0001193125-23-227699 | 10-Q | XBRL Viewer

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Leases - Additional Information (Detail) $ in Thousands		1 Months Ended							6 Months Ended
Leases - Additional Information (Detail) $ in Thousands	Dec. 01, 2019	Nov. 30, 2022	Sep. 30, 2022 USD ($)	Mar. 31, 2022	Jun. 30, 2021 ft²	May 31, 2019 ft²	Jan. 31, 2019 ft²	Jul. 31, 2018 ft²	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Nov. 30, 2019 USD ($)	Nov. 01, 2018
Lessee, Lease, Description [Line Items]
Operating lease, impairment loss			$ 500
Lessee, operating lease, liability, to be paid									$ 4,430
Payments for rent									900	$ 1,100
Operating lease, payments									$ 1,200	$ 700
Operating lease agreement [Member]
Lessee, Lease, Description [Line Items]
Number of square feet for lease \| ft²						9,423
Lessee, operating lease, term of contract	5 years
Lessee, operating lease, option to extend	one renewal option for a period of five years
Lessee, operating lease, renewal term	5 years
Office space [Member] \| Operating lease agreement [Member]
Lessee, Lease, Description [Line Items]
Number of square feet for lease \| ft²								6,500
Lessee, operating lease, term of contract												7 years 3 months
Laboratory space [Member] \| Operating lease agreement [Member]
Lessee, Lease, Description [Line Items]
Number of square feet for lease \| ft²							6,000
Lessee, operating lease, term of contract											3 years
Lessee, operating lease, liability, to be paid											$ 100
Lessee, operating lease, option to extend		the lease was extended for a one year period with the option to renew for an additional one year term which the Company does not plan to exercise.
Lessee, operating lease, renewal term		1 year
Office and laboratory space [Member] \| Operating lease agreement [Member]
Lessee, Lease, Description [Line Items]
Number of square feet for lease \| ft²					19,474
Lessee, operating lease, term of contract				38 months
Lessee, operating lease, option to extend				one renewal option for a period of three years and commenced in March 2022
Lessee, operating lease, renewal term				3 years

Asset Acquisition - Additional Information (Detail) - USD ($) $ in Thousands						1 Months Ended		3 Months Ended		6 Months Ended		12 Months Ended
	Jul. 25, 2023	Jun. 30, 2023	Jun. 14, 2022	Jun. 08, 2022	Dec. 15, 2020	Jan. 31, 2023	Jul. 31, 2022	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2020	Jan. 10, 2023	Jul. 28, 2022	Jul. 25, 2022	May 31, 2022
Asset Acquisition [Line Items]
Payment for contingent consideration liability										$ 898
Third Milestone Payment [Member]
Asset Acquisition [Line Items]
Contingent consideration payable					$ 20,000
Langer [Member] \| Second Milestone Payment [Member]
Asset Acquisition [Line Items]
Contingent consideration payable															$ 9,400
Contingent consideration payable by shares							$ 5,000
Contingent consideration payable by cash													$ 2,200	$ 2,200
Stock issued during the period for milestone payments shares				212,203
Stock issued during the period for milestone payments value				$ 5,000
Payment for contingent consideration liability						$ 2,200	2,200
Myst Holders [Member] \| Second Milestone Payment [Member]
Asset Acquisition [Line Items]
Contingent consideration payable															10,000	$ 10,000
Contingent consideration payable by shares																5,000
Contingent consideration payable by cash																$ 5,000
Payment for contingent consideration liability							2,800
Remaining Myst Holders [Member] \| Second Milestone Payment [Member]
Asset Acquisition [Line Items]
Contingent consideration payable by cash															$ 600
Payment for contingent consideration liability							$ 600
Myst Merger Agreement [Member]
Asset Acquisition [Line Items]
Payments to acquire productive assets			$ 1,000		9,000
Research and development contract obligation assumed					1,500
Commitment to spend for cell therapy infrastructure and continued research and development					30,000
Research and development asset acquired other than through business combination, write-off												$ 19,400
Asset acquisition contingent consideration arrangements change in amount of contingent consideration, liability								$ 300	$ 6,200	$ 900	$ 6,500
Myst Merger Agreement [Member] \| Second Milestone Payment [Member]
Asset Acquisition [Line Items]
Contingent consideration payable					$ 10,000
Myst Merger Agreement [Member] \| Subsequent Event [Member] \| Initial Milestone Payment [Member]
Asset Acquisition [Line Items]
Contingent consideration, liability	$ 3,000
Number of trading days	20 days
Myst Merger Agreement [Member] \| Langer [Member]
Asset Acquisition [Line Items]
Asset acquisition, consideration transferred, equity interest issued and issuable shares			725,920
Asset acquisition consideration transferred equity interest issued shares			362,960
Asset acquisition consideration transferred equity interest issuable shares			362,960
Myst Merger Agreement [Member] \| Langer [Member] \| Restricted Stock [Member]
Asset Acquisition [Line Items]
Percentage of vesting of award under share-based payment arrangement			25.00%
Number of equity-based payment instruments vested during the period		181,480
Number of non-vested equity-based payment instruments		181,480						181,480		181,480
Award vesting period										1 year 6 months

Summary of Significant Accounting Policies	6 Months Ended
Summary of Significant Accounting Policies	Jun. 30, 2023
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation of Unaudited Condensed Consolidated Financial Information The accompanying unaudited condensed consolidated financial statements of the Company have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) for interim financial information and pursuant to the rules and regulations of the SEC. Accordingly, they do not include all the information and footnotes required by GAAP for complete financial statements. However, such interim financial statements reflects all adjustments (consisting solely of normal recurring adjustments), which are, in the opinion of management, necessary for the fair presentation of the Company’s financial position and results of operations. Results shown for interim periods are not necessarily indicative of the results that may be expected for the year ended December 31, 2023 or for any other period. The condensed consolidated balance sheet as of December 31, 2022 was derived from the audited consolidated financial statements. These unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements, included in the Company’s final prospectus filed with the SEC pursuant to Rule 424(b)(4) on July 2 4 , 2023. Certain prior period amounts reported in the Company’s unaudited condensed consolidated financial statements and accompanying notes have been reclassified to conform to the current period presentation. Any reference in these notes to applicable guidance is meant to refer to the authoritative accounting principles generally accepted in the United States as found in the Accounting Standard Codification (“ASC”) and Accounting Standards Update (“ASU”) of the Financial Accounting Standards Board (“FASB”). Principles of Consolidation The accompanying unaudited condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. Significant Accounting Policies The significant accounting policies used in preparation of these unaudited condensed consolidated financial statements are consistent with those discussed in Note 2 to the audited consolidated financial statements included in the Company’s final prospectus filed with the SEC pursuant to Rule 424(b)(4) on July 2 4 , 2023. Use of Estimates The preparation of these unaudited condensed consolidated financial statements in accordance with GAAP requires management to make estimates and assumptions that affect the amounts reported in the unaudited condensed consolidated financial statements and accompanying notes. On an ongoing basis, management evaluates its estimates, including those related to accrued expenses, contingent liabilities, revenue recognition, the valuation of equity-based compensation, common stock, restricted common stock, and income taxes. The Company bases its estimates on various assumptions that the Company believes to be reasonable under the circumstances. Actual results could differ from those estimates. Restricted Cash and Investments Restricted cash consists of certificate of deposit accounts that are pledged as collateral for the Company’s San Diego facility lease as of June 30, 2023 and the San Diego and New York facility leases as of December 31, 2022. Restricted cash was approximately $0.1 million and $0.4 million as of June 30, 2023 and December 31, 2022, respectively. The Company invests its excess cash in investment grade, short-term, fixed income securities and recognizes purchased securities on the settlement date. All investments have been classified as “available-for-sale” in the unaudited condensed consolidated balance sheets, and are carried at estimated fair value based upon quoted market prices or pricing models for similar securities. Management determines the appropriate classification of its investments at the time of purchase and re-evaluates such designation as of each balance sheet date. The Company assesses its available-for-sale securities under the available-for-sale security impairment model in ASC 326 as of each reporting date in order to determine if a portion of any decline in fair value below carrying value is the result of a credit loss. The Company records credit losses in the unaudited condensed consolidated statements of operations and comprehensive income (loss) as credit loss expense, which is limited to the difference between the fair value and the amortized cost of the security. To date, the Company has not recorded any credit losses on its available-for-sale securities. Declines in fair value below carrying value attributable to non-credit related factors are recorded as accumulated other comprehensive loss, which is a separate component of stockholders’ deficit. Realized gains and losses are reported in other income (expense), net. Interest on short-term investments is included in other income (expense), net. The Company’s investments are classified as current assets, even though the stated maturity date may be one year or more beyond the current balance sheet date, which reflects management’s intention to use the proceeds from sales of these securities to fund its operations, as necessary. Concentration of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash and cash equivalents, investments and restricted cash. The Company’s investment policy restricts cash investments to high credit quality, investment grade investments. The Company’s investment policy provides guidelines and limits regarding investment type, concentration, credit quality, and maturity aimed at maintaining sufficient liquidity to satisfy operating and working capital requirements along with strategic initiatives, preserving capital, and minimizing risk of capital loss while generating returns on its investments. The Company is exposed to credit risk in the event of default by the issuer or the institutions holding the cash and cash equivalents to the extent of the amounts recorded on the balance sheets. The Company records accounts receivable amounts invoiced to a collaborator, for which the Company has an unconditional right to consideration. For amounts to which the Company has an unconditional right to consideration but has not yet invoiced the collaborator, the Company records unbilled accounts receivable. The Company estimates an allowance for credit losses based on the creditworthiness of its collaborator, current economic conditions and future economic conditions, as may be applicable. If a receivable is deemed to be uncollectible, the balance is charged against the allowance. As of June 30, 2023 and December 31, 2022, the Company had an accounts receivable balance of $ 0.3 million and $8.7 million, respectively of which Takeda accounted for 100%, and no allowance was recorded. Accounts receivable and unbilled accounts receivable are presented in accounts receivable, net on the unaudited condensed consolidated balance sheets. During the three months and six months ended June 30, 2023 and 2022, the Company did not recognize any charges for write-offs of accounts receivable. The Company has no off-balance sheet risk, such as foreign exchange contracts, option contracts or other foreign-hedging arrangements. Fair Value Measurements The Company applies fair value accounting for all financial assets and liabilities and non-financial assets and liabilities that are recognized or disclosed at fair value in the unaudited condensed consolidated financial statements on a recurring basis. Fair value is defined as the exchange price that would be received for an asset or an exit price that would be paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The fair value hierarchy requires that an entity maximize the use of observable inputs when estimating fair value. The fair value hierarchy includes the following three-level classification which is based on the market observability of the inputs used for estimating the fair value of the assets or liabilities being measured: Level 1 – Quoted market prices in active markets for identical assets or liabilities. Level 2 – Observable inputs other than quoted prices in active markets for identical assets and liabilities, quoted prices for identical or similar assets or liabilities in inactive markets, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3 – Inputs that are generally unobservable and typically reflect management’s estimate of assumptions that a market participant would use in pricing the asset or liability. Fair value accounting is applied for all financial assets and liabilities and non-financial assets and liabilities that are recognized at fair value in the unaudited condensed consolidated financial statements on a recurring basis (at least annually). To the extent the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair values requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized as Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. Stock-Based Compensation The Company measures the cost of employee, nonemployee and director services received in exchange for an award of equity instruments based on the fair value of the award on the date of grant and recognizes the related expense over the period during which the employee, nonemployee or director is required to provide service in exchange for the award on a straight-line basis. The Company estimates the fair value of options granted using the Black-Scholes option pricing model (“Black-Scholes”) and the fair value of common stock to determine the fair value of restricted stock. The determination of fair value for stock-based awards on the date of grant using an option-pricing model requires management to make certain assumptions regarding a number of variables. Upon adoption of ASU 2016-09, the Company can make an accounting policy election to either estimate the number of share-based awards that are expected to vest, or account for forfeitures when they occur. The Company elected to account for forfeitures when they occur. As such, the Company recognizes stock-based compensation expense, over the requisite service period, based on the vesting provisions of the individual grants. The Black-Scholes option pricing model requires inputs based on certain subjective assumptions, including (a) the expected stock price volatility, (b) the expected term of the award, (c) the risk-free interest rate and (d) expected dividend yields. Due to the lack of a public market for the Company’s common stock until July 21, 2023, and lack of company- specific historical and implied volatility data, the Company has based its computation of expected volatility on the average historical volatility of a representative group of public companies with similar characteristics to the Company, including stage of product development and life science industry focus. The historical volatility is calculated based on a period of time commensurate with the expected term. The Company uses the simplified method as prescribed by the U.S. Securities and Exchange Commission Staff Accounting Bulletin No. 107, Share-Based Payment, to calculate the expected term for options granted to employees as it does not have sufficient historical exercise data to provide a reasonable basis upon which to estimate the expected term. The expected term is applied to the stock option grant group as a whole, as the Company does not expect substantially different exercise or post-vesting termination behavior among its employee population. The risk-free interest rate is based on a treasury instrument whose term is consistent with the expected term of the stock options. The expected dividend yield is assumed to be zero as the Company has never paid dividends and has no current plans to pay any dividends on its common stock. Determination of Fair Value of Common Stock There are significant judgments and estimates inherent in the determination of the fair value of the Company’s common stock. These estimates and assumptions include a number of objective and subjective factors, including, among other things, external market conditions, the prices at which the Company sold shares of its convertible preferred stock, the superior rights and preferences of securities senior to its common stock at the time of, and the likelihood of, achieving a liquidity event, such as an initial public offering or sale of the Company. The approach to estimating the fair market value of common stock is consistent with the methods outlined in the American Institute of Certified Public Accountants’ Accounting and Valuation Guide, Valuation of Privately-Held Company Equity Securities Issued as Compensation (the “Practice Aid”). In valuing the Company’s common stock, the equity value of the business was determined using the backsolve method, a form of the subject company transaction method, wherein the equity value for a privately held company is derived from a recent transaction in the company’s own securities. The value is then allocated using the hybrid method allocation methodology. For grants made prior to September 30, 2018, in accordance with the Practice Aid, the Company determined the option pricing method (“OPM”), was the most appropriate method for determining the fair value of the Company’s common stock based on its stage of development and other relevant factors. For grants made subsequent to September 30, 2018, the Company used a hybrid method, which is a hybrid between the OPM and the probability-weighted expected return method (“PWERM”). The hybrid method is a combination of the PWERM and OPM. The OPM allocates the overall Company value to the various share classes based on differences in liquidation preferences, participation rights, dividend policy and conversion rights, using a series of call options. The call right is valued using a Black-Scholes option pricing model. The PWERM employs additional information not used in the OPM, including various market approach calculations depending upon the likelihood of various discrete future liquidity scenarios, such as an initial public offering or sale of the Company, as well as the probability of remaining a private company. In a hybrid method, various exit scenarios are analyzed. A discount for lack of marketability of the Company’s common stock is then applied to arrive at an indication of value for the common stock. Redeemable Convertible Preferred Stock The Company records all proceeds from redeemable convertible preferred stock (“Preferred Stock”) net of issuance costs. The Company classifies Preferred Stock outside of stockholders’ deficit due to certain events that are outside of the Company’s control, including sale or transfer of control of the Company, or redemption upon the election of the required majority of the Preferred Stockholders any time after June 29, 2026, as holders of the Preferred Stock could cause redemption of the shares in these situations. The Company adjusts the carrying values of the Preferred Stock to the ultimate redemption values over the period from issuance to the earliest redemption date. Deferred Offering Costs The Company has deferred offering costs consisting of legal, accounting and other fees and costs directly attributable to the Company’s IPO and are included with other assets, noncurrent in the balance sheets. The deferred offering costs will be offset against the proceeds received upon the completion of the IPO. As of June 30, 2023 and December 31, 2022, the Company recorded $ 4.4 million and $1.9 million of deferred offering costs, respectively. Contingent Consideration Consideration paid related to the Myst Merger Agreement (as defined below) may include potential future payments that are contingent upon the Company achieving certain milestones in the future. Contingent consideration liabilities are measured at their estimated fair value as of the date of the unaudited condensed consolidated balance sheets using a probability-based income approach based on the monetary value of the milestone payment discounted for the likelihood of achieving the milestone and a present value factor based on the timing of when the milestone is expected to be achieved. Contingent consideration liabilities expected to be settled within 12 months after the balance sheet date are presented in current liabilities, with the non-current portion recorded under other liabilities, non-current in the unaudited condensed consolidated balance sheets. Changes in the fair value of the contingent consideration are recorded as research and development expenses in the unaudited condensed consolidated statement of operations and comprehensive income (loss). Recently Adopted Accounting Pronouncements In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326)—Measurement of Credit Losses on Financial Instruments, which has been subsequently amended by ASU No. 2018-19, ASU No. 2019-04, ASU No. 2019-05, ASU No. 2019-10, ASU No. 2019-11 and ASU No. 2021-03 (“ASU 2016-13”). The provisions of ASU 2016-13 modify the impairment model to utilize an expected loss methodology in place of the currently used incurred loss methodology and require a consideration of a broader range of reasonable and supportable information to inform credit loss estimates. ASU 2016-13 is effective for the Company on January 1, 2023. The adoption did not have a material impact on the unaudited condensed consolidated financial statements. Recently Issued Accounting Pronouncements In August 2020, the FASB issued ASU No. 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging Contracts in Entity’s Own Equity (Subtopic 815-40) (“ASU 2020-06”), which reduces the number of accounting models for convertible debt instruments and convertible preferred stock as well as amends the derivatives scope exception for contracts in an entity’s own equity. ASU 2020-06 is effective for the Company on January 1, 2024, with early adoption permitted. The Company is currently evaluating the potential impact that this standard may have on its unaudited condensed consolidated financial statements and related disclosures.

Stockholders' Equity

6 Months Ended

Jun. 30, 2023

Stockholders' Equity Note [Abstract]

Stockholders' Equity

8. Stockholders’ Equity

Series A Preferred Stock

From October 2015 to October 2016, the Company issued a total of 11,250,000 shares of series A preferred stock (the “Series A Preferred Stock”) at CDN$1.00 per share (equivalent to $0.74 per share, based on a conversion ratio of 1.344 Canadian dollars to one U.S. dollar) for total net proceeds of CDN$ 10.9 million (equivalent to $8.1 million based on a conversion ratio of 1.344 Canadian dollars to one U.S. dollar).

Series B Preferred Stock

In October 2016, the Company issued a total of 16,285,156 shares of series

B-1

preferred stock (the “Series

B-1

Preferred Stock”) at $0.77 per share for total net proceeds of $12.3 million. In November 2018, the Company issued 25,065,538 shares of series

B-2

preferred stock (the “Series

B-2

Preferred Stock”, and together with the Series

B-1

Preferred Stock, the “Series B Preferred Stock”) at $1.15 per share for total net proceeds of $28.9 million.

Series C Preferred Stock

The Company issued a total of 17,905,288 shares of series C preferred stock (the “Series C Preferred Stock”) at $2.35 per share in January 2019 for net proceeds of $41.8 million.

Series D Preferred Stock

The Company issued a total of 29,285,356 shares of series D preferred stock (the “Series D Preferred Stock”) at $2.73 per share in June 2021 for net proceeds of $79.8 million.

The rights and preferences of the Preferred Stock as of June 30, 2023, are summarized below, which relate to each of the Series A, Series B, Series C and Series D Preferred Stock unless specified otherwise.

Conversion

The holders of Preferred Stock have the right, at any time and at the holder’s discretion, to convert, without payment of any additional consideration, in whole or in part, such holder’s Preferred Stock into common stock at the then applicable conversion price, which shall initially be one share of common stock for one share of Preferred Stock. The Preferred Stock will be automatically converted into common stock at the then applicable conversion price, upon the earlier of a qualified initial public offering or the election of a required majority of the holders of Preferred Stock.

Voting

The holders of the Preferred Stock are entitled to vote on any matters on which holders of common stock are entitled to vote, on an

as-converted

basis. Holders of Preferred Stock and holders of common stock are required to vote together as a single class, except for meetings at which only holders of another specified class of shares are entitled to vote. Each Preferred Stockholder is entitled to such number of votes equal to the number of shares of common stock issuable upon the exercise of any conversion rights attaching to such Preferred Stock at the date of such vote, using the applicable conversion price.

Dividends

The holders of the Series A and Series B Preferred Stock are entitled to receive

non-cumulative

dividends at the rate of 8% per annum and the holders of the Series C and Series D Preferred Stock are entitled to receive

non-cumulative

dividends at the rate of 10% per annum when and if declared by the board of directors and in preference to the common stock. After the preferred dividend is paid, the Preferred Stock participates in any dividend paid to common stock on an

as-converted

basis (participating). Through June 30, 2023, the Company has not declared or paid dividends and has no present intention of paying any dividends in the foreseeable future.

Liquidation Preference

In the event of a liquidation event, the holders of Preferred Stock are entitled to receive, in preference to the holders of common stock, an amount equal to their initial issue price plus the aggregate of all declared but unpaid dividends and may then participate in the distribution of any residual assets with the common stock on an

as-converted

basis.

If the amount to distribute is insufficient to pay the liquidation preference in full, then the Preferred Stock receive the distribution ratably in proportion to the respective amounts which would otherwise be payable in respect of the shares held by them upon such distribution if all amounts payable on or with respect to such shares were paid in full.

Redemption

At the option of the holders of at least a majority of the then outstanding shares of Preferred Stock, consenting or voting together as a single class on an

as-converted

to Common Stock basis (the “Required Majority”), at any time after June 29, 2026, each holder of Preferred Stock shall be entitled to require the Company to redeem all or any of the outstanding Preferred Stock held by those holders electing at a price equal to the Redemption Price which is defined as initial issue price plus declared but unpaid dividends.

The Company is accreting the carrying value of the Preferred Stock up to the full redemption value over the period from issuance to the earliest redemption date. The Company recorded accretion totaling $0.0 million and $0.1 million for the six months ended June 30, 2023 and 2022, respectively. As of June 30, 2023 and December 31, 2022, the full redemption value of the Preferred Stock is $172.0 million and $171.9 million, respectively. As of June 30, 2023, no shares have been redeemed.

The Company has assessed whether there are any embedded derivatives or beneficial conversion option relating to the preferred stock and determined that none exist.

Anti-Dilution Protection

If the Company issues additional securities without consideration or for consideration per share less than the initial issue price of a series of Preferred Stock (other than certain customary exceptions), then the conversion price for the applicable series of Preferred Stock will be adjusted using a broad-based weighted average anti-dilution formula.

Common Stock

As of June 30, 2023, the Company’s certificate of incorporation, as amended and restated, authorized the Company to issue 147,892,358 shares of common stock, $0.001 par value per share. The common stockholders are entitled to receive dividends, in subordination to the Series A, Series B, Series C and Series D Preferred Stock, if and when declared by the board of directors. In the event of dissolution, the common stock ranks in seniority behind the Series A, Series B, Series C and Series D Preferred Stock. The holders of common stock are entitled to one vote for each share held.

Shares of common stock reserved for future issuance, on an

as-if-converted

basis, consisted of the following:


	June 30, 2023		December 31, 2022
Series A redeemable convertible preferred stock		1,408,502		1,408,502
Series B-1 redeemable convertible preferred stock		2,038,903		2,038,903
Series B-2 redeemable convertible preferred stock		3,138,208		3,138,208
Series C redeemable convertible preferred stock		2,241,740		2,241,740
Series D redeemable convertible preferred stock		3,666,526		3,666,526
Stock options, issued and outstanding		2,604,639		1,759,275
Stock options, available for future issuance		159,243		830,774

		15,257,761		15,083,928

- Definition

The entire disclosure for equity.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Section 50
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
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-Paragraph 1
-Subparagraph (SX 210.4-08(e)(1))
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Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//505/tableOfContent

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-14

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-14

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 16
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-16

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-18

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-18

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-18

+ Details

Asset Acquisition	6 Months Ended
Asset Acquisition	Jun. 30, 2023
Asset Acquisition [Abstract]
Asset Acquisition	7. Asset Acquisition In December 2020, the Company entered into the Agreement and Plan of Merger and Reorganization (the “Myst Merger Agreement”), by and among the Company, Flatiron Merger Sub I, Inc. (“Merger Sub”), Flatiron Merger Sub II, LLC (“Merger LLC”), a direct, wholly-owned subsidiary of the Company, Myst Therapeutics, Inc. (“Myst”), and Timothy Langer, the sole common stockholder of Myst (“Langer”). Pursuant to the Myst Merger Agreement, the business combination (the “Merger”) was effected in two steps. The first step was the merger of Merger Sub with and into Myst. The second step was the merger of Myst with and into Merger LLC. The Merger closed on December 14, 2020, and the effective date of the Merger was January 20, 2021 As a result of the Merger, the separate existences of Merger Sub and Myst ceased, and Merger LLC became the Company’s wholly-owned subsidiary. Pursuant to the Myst Merger Agreement, on December 15, 2020, the Company paid the former equity holders of Myst, (the “Myst Holders”), a one-time up-front payment of $9.0 million in cash. The Company paid an additional cash consideration of $1.0 million to the Myst Holders on June 14, 2022. The Company also issued Langer up to 725,920 shares of the Company’s common stock. Of these shares, 362,960 shares of the Company’s common stock were issued upon the closing of the Merger and the remaining 362,960 shares of the Company’s common stock were held in escrow with 25% vesting in December of each year that Langer remains an employee of the Company. As of June 30, 2023, Langer is still employed by the Company and 181,480 shares of the Company’s common stock have vested and been released from escrow with the remaining 181,480 shares of the Company’s common stock to be released in equal annual installments over the next 1.5 years based on his continued employment. This restricted equity grant is accounted for as a compensatory arrangement under ASC 718 as continued service is required under the agreement. In addition, under the Myst Merger Agreement, each Myst Holder is entitled to receive certain payments as consideration based on the achievement by the Company of three predefined milestones. The initial milestone is the closing of an initial public offering, which occurred on July 25, 2023, the second milestone is the first acceptance by the FDA of an IND filed by, on behalf of or for the benefit of the Company, or the Company’s sublicensees for a product being developed by or on behalf of the Company or its sublicensees that is claimed as a product or method of making or using the product by a pending or issued Myst patent claim existing at the time of such acceptance, and the third milestone is the occurrence of the earlier of (i) the commencement of the first registration study for a product being developed by, on behalf of or for the benefit of the Company that is claimed as a product or a method of making or using the product by an issued Myst patent claim existing as of the time of such commencement or (ii) the issuance of a Myst patent claim that claims a product or method of making or using the product then being developed by, on behalf of or for the benefit of the Company, or its sublicensees, that is or was the subject of a registration study that has or had commenced. The milestones are not contingent on one another, and the milestones do not need to be achieved in any specific order. Within 45 days of the achievement of the initial milestone, which occurred on July 25, 2023, the Company is obligated to pay the Myst Holders an aggregate amount equal to $3.0 million. At the Company’s election, the Company may pay this consideration in cash or in shares of the Company’s common stock. The fair market value of the Company’s common stock measured after the IPO, is the volume weighted-average closing price of the Company’s common stock on Nasdaq for the consecutive 20 trading day period ending on the last trading day on or prior to the date on which the milestone was earned pursuant to the Myst Merger Agreement. Within 45 days of the achievement of the second milestone, the Company is obligated to pay the Myst Holders an aggregate amount equal to $10.0 million. At the Company’s election, the Company may pay this consideration in cash or in shares of the Company’s common stock. In May 2022, this $10.0 million milestone was achieved. The Company elected to pay $5.0 million in the Company’s common stock and $5.0 million in cash. Pursuant to a letter agreement dated July 25, 2022 between the Company and the former equityholders of Myst regarding the $10.0 million milestone payment that became due and owing to the Myst Holders, the Company agreed to pay to the former optionholders of Myst on or before July 28, 2022, $0.6 million in cash, with the remaining $9.4 million payable to Langer as follows: (i) on or before July 28, 2022, $2.2 million in cash, (ii) on or before July 31, 2022, $5.0 million in shares of the Company’s common stock and (iii) on or before January 10, 2023, $2.2 million in cash. On June 8, 2022, the Company issued Langer 212,203 shares of the Company’s common stock to settle the $5.0 million obligation payable in common stock. The Company then paid the Myst Holders $2.8 million in July 2022, with $2.2 million paid to Langer and $0.6 million paid to the remaining Myst Holders, and the remaining $2.2 million was paid to Langer in January 2023. Within 45 days of the achievement of the third milestone, the Company is obligated to pay the Myst Holders an aggregate amount equal to $20.0 million. At the Company’s election, the Company may pay this consideration in cash or in shares of its common stock. Additionally, the Company assumed an ongoing research and development contract obligation of approximately $1.5 million and committed to spend at least $30.0 million for building out the cell therapy infrastructure and continued research and development. The Company accounted for the merger with Myst pursuant to the Myst Merger Agreement as an asset acquisition as substantially all of the value received was concentrated in the acquired in-process research and development of Myst and did not have an alternate future use. The Company recognized a $19.4 million charge to research and development expense at the time of the completion of the asset acquisition during the year ended December 31, 2020. The Company determined that the milestone payments are separate units of account and accounted for the initial milestone as a derivative in accordance with ASC 815 and the second and third milestones as liabilities in accordance with ASC 480. In connection with the initial public offering, the Company reassessed its initial accounting of the milestone payments and concluded that they should be viewed as one unit of account because the milestone payments are not legally detachable from each other. The milestone payments, as one unit of account, would be classified as a liability in accordance with ASC 480 and measured at fair value, with changes in the fair value recorded in earnings. Regardless of whether the milestone payments are viewed as one unit of account or three units of account, because they are all subject to fair value measurement, the financial reporting effect of the contingent consideration arrangement as one unit of account or three units of account is substantially the same. As a liability under ASC 480, the contingent consideration will continue to be recorded at fair value until settled. The adjustment to the fair value of the contingent consideration of $0.3 million and $ 6.2 million for the three months ended June 30, 2023 and 2022, respectively, and $0.9 million and $6.5 million for the six months ended June 30, 2023 and 2022, respectively were included in research and development expense in the Company’s unaudited condensed consolidated statements of operations and comprehensive income (loss).

Cover Page - shares	6 Months Ended
Cover Page - shares	Jun. 30, 2023	Aug. 29, 2023
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Amendment Flag	false
Document Period End Date	Jun. 30, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q2
Entity Registrant Name	Turnstone Biologics Corp.
Entity Central Index Key	0001764974
Entity File Number	001-41747
Entity Tax Identification Number	83-2909368
Entity Incorporation, State or Country Code	DE
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	No
Entity Interactive Data Current	Yes
Entity Shell Company	false
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Address, Address Line One	9310 Athena Circle
Entity Address, Address Line Two	Suite 300
Entity Address, City or Town	La Jolla
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92037
City Area Code	347
Local Phone Number	897-5988
Title of 12(b) Security	Common Stock ($0.001 par value)
Trading Symbol	TSBX
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		22,842,144

Fair Value of Financial Assets and Liabilities - Schedule of company's cash, cash equivalents and available-for-sale securities (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2023	Dec. 31, 2022
Fair Value Disclosures [Line Items]
Amortized cost	$ 44,372	$ 57,140
Gross unrealized gains	5
Gross unrealized losses	(15)	(190)
Estimated fair value	44,362	56,950
Money market funds [Member] \| Level 1 [Member]
Fair Value Disclosures [Line Items]
Amortized cost	16,540	9,238
Estimated fair value	16,540	9,238
Restricted cash [Member]
Fair Value Disclosures [Line Items]
Estimated fair value	116	382
Restricted cash [Member] \| Level 1 [Member]
Fair Value Disclosures [Line Items]
Amortized cost	116	382
Estimated fair value	116	382
U.S. government and agency securities [Member] \| Level 1 [Member]
Fair Value Disclosures [Line Items]
Amortized cost	18,743	30,761
Gross unrealized gains	5
Gross unrealized losses	(2)	(112)
Estimated fair value	18,746	30,649
U.S. government and agency securities [Member] \| Level 2 [Member]
Fair Value Disclosures [Line Items]
Amortized cost	8,973	16,759
Gross unrealized losses	(13)	(78)
Estimated fair value	8,960	16,681
Cash and cash equivalents [Member]
Fair Value Disclosures [Line Items]
Estimated fair value	16,540	9,238
Short-term investments [Member]
Fair Value Disclosures [Line Items]
Estimated fair value	$ 27,706	$ 47,330

Agreements - Schedule Of Transaction Price Allocated To Programs Performance Obligation (Detail) $ in Millions	Jun. 13, 2023 USD ($)
Price Pre-Modification [Member]
Schedule Of Transaction Price Allocatied To Programs Performance Obligation [Line Items]
Performance Obligations	$ 192.6
Price at Modification [Member]
Schedule Of Transaction Price Allocatied To Programs Performance Obligation [Line Items]
Performance Obligations	155.5
Development Program [Member] \| Price Pre-Modification [Member]
Schedule Of Transaction Price Allocatied To Programs Performance Obligation [Line Items]
Performance Obligations	166.3
Development Program [Member] \| Price at Modification [Member]
Schedule Of Transaction Price Allocatied To Programs Performance Obligation [Line Items]
Performance Obligations	134.3
Discovery Program [Member] \| Price Pre-Modification [Member]
Schedule Of Transaction Price Allocatied To Programs Performance Obligation [Line Items]
Performance Obligations	26.3
Discovery Program [Member] \| Price at Modification [Member]
Schedule Of Transaction Price Allocatied To Programs Performance Obligation [Line Items]
Performance Obligations	$ 21.2

Fair Value of Financial Assets and Liabilities - Schedule of company's contingent consideration measured at fair value level 3 (Detail) - Contingent consideration [Member] $ in Thousands	6 Months Ended
	Jun. 30, 2023 USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 5,994
Cash payment of Myst milestone	(2,187)
Changes in the fair value of contingent consideration	876
Ending balance	$ 4,683

Stockholders' Equity - Additional Information (Detail) $ / shares in Units, $ / shares in Units, $ in Thousands, $ in Millions		1 Months Ended				3 Months Ended		6 Months Ended		13 Months Ended
	Jun. 30, 2023 USD ($) $ / shares shares	Jun. 30, 2021 USD ($) $ / shares shares	Jan. 31, 2019 USD ($) $ / shares shares	Nov. 30, 2018 USD ($) $ / shares shares	Oct. 31, 2016 USD ($) $ / shares shares	Jun. 30, 2023 USD ($) $ / shares shares	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($) $ / shares shares	Jun. 30, 2022 USD ($)	Oct. 31, 2016 USD ($) $ / shares shares	Oct. 31, 2016 CAD ($) shares	Dec. 31, 2022 USD ($) $ / shares	Oct. 31, 2016 $ / shares
Class of Stock [Line Items]
Accretion of preferred stock to redemption value						$ 19	$ 57	$ 39	$ 114
Common stock, par or stated value per Share \| $ / shares	$ 0.001					$ 0.001		$ 0.001				$ 0.001
Description of voting rights of common stock	one vote for each share
Common stock aggregate issues \| shares	147,892,358					147,892,358		147,892,358
Series A Preferred Stock [Member]
Class of Stock [Line Items]
Number of stock classified as temporary equity issued during the period \| shares										11,250,000	11,250,000
Shares issued, price per share \| (per share)					$ 0.74					$ 0.74			$ 1
Foreign exchange rate					1.344					1.344			1.344
Value of new stock classified as temporary equity issued during the period										$ 8,100	$ 10.9
Temporary Equity, aggregate amount of redemption requirement	$ 8,643					$ 8,643		$ 8,643
Series B1 Redeemable Convertible Preferred Stock [Member]
Class of Stock [Line Items]
Number of stock classified as temporary equity issued during the period \| shares					16,285,156
Shares issued, price per share \| $ / shares					$ 0.77					$ 0.77
Proceeds from Issuance of redeemable convertible preferred stock					$ 12,300
Temporary Equity, aggregate amount of redemption requirement	12,611					12,611		12,611
Series B2 Redeemable Convertible Preferred Stock [Member]
Class of Stock [Line Items]
Number of stock classified as temporary equity issued during the period \| shares				25,065,538
Shares issued, price per share \| $ / shares				$ 1.15
Proceeds from Issuance of redeemable convertible preferred stock				$ 28,900
Temporary Equity, aggregate amount of redemption requirement	28,860					28,860		28,860
Series C Preferred Stock [Member]
Class of Stock [Line Items]
Number of stock classified as temporary equity issued during the period \| shares			17,905,288
Shares issued, price per share \| $ / shares			$ 2.35
Proceeds from Issuance of redeemable convertible preferred stock			$ 41,800
Temporary Equity, aggregate amount of redemption requirement	42,100					42,100		42,100
Series D Preferred Stock [Member]
Class of Stock [Line Items]
Number of stock classified as temporary equity issued during the period \| shares		29,285,356
Shares issued, price per share \| $ / shares		$ 2.73
Proceeds from Issuance of redeemable convertible preferred stock		$ 79,800
Temporary Equity, aggregate amount of redemption requirement	$ 80,000					$ 80,000		$ 80,000
Series A and Series B redeemable convertible preferred stock [Member]
Class of Stock [Line Items]
Temporary equity dividend rate	8.00%					8.00%		8.00%
Series Series C and Series D redeemable convertible preferred stock [Member]
Class of Stock [Line Items]
Temporary equity dividend rate	10.00%					10.00%		10.00%
Redeemable Convertible Preferred Stock [Member]
Class of Stock [Line Items]
Accretion of preferred stock to redemption value								$ 0	$ 100
Temporary Equity, aggregate amount of redemption requirement	$ 172,000					$ 172,000		$ 172,000				$ 171,900
Temporary equity aggregate stock redeemed \| shares	0					0		0

Accrued Expenses and Other Current Liabilities - Schedule of Accrued Liabilities and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Accrued Liabilities and Other Liabilities [Abstract]
Research and development expense	$ 8,534	$ 6,688
Professional and consulting expense	3,104	1,170
Compensation	2,496	2,366
Tax liability, current	83	252
Contingent consideration, current	2,250	3,791
Other current liabilities		20
Total accrued expenses and other current liabilities	$ 16,467	$ 14,287

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Common stock, par or stated value per Share	$ 0.001	$ 0.001
Common stock, shares authorized	147,892,358	147,892,358
Common stock, shares, outstanding	3,029,258	2,915,757
Common stock, shares, issued	3,029,258	2,915,757
Series A Preferred Stock [Member]
Temporary equity, par or stated value per share	$ 0.001	$ 0.001
Temporary equity, shares authorized	11,250,000	11,250,000
Temporary equity, shares issued	11,250,000	11,250,000
Temporary equity, shares outstanding	11,250,000	11,250,000
Temporary Equity, aggregate amount of redemption requirement	$ 8,643
Series B-1 redeemable convertible preferred stock [Member]
Temporary equity, par or stated value per share	$ 0.001	$ 0.001
Temporary equity, shares authorized	16,285,156	16,285,156
Temporary equity, shares issued	16,285,156	16,285,156
Temporary equity, shares outstanding	16,285,156	16,285,156
Temporary Equity, aggregate amount of redemption requirement	$ 12,611
Series B-2 redeemable convertible preferred stock [Member]
Temporary equity, par or stated value per share	$ 0.001	$ 0.001
Temporary equity, shares authorized	25,065,538	25,065,538
Temporary equity, shares issued	25,065,538	25,065,538
Temporary equity, shares outstanding	25,065,538	25,065,538
Temporary Equity, aggregate amount of redemption requirement	$ 28,860
Series C Preferred Stock [Member]
Temporary equity, par or stated value per share	$ 0.001	$ 0.001
Temporary equity, shares authorized	17,905,288	17,905,288
Temporary equity, shares issued	17,905,288	17,905,288
Temporary equity, shares outstanding	17,905,288	17,905,288
Temporary Equity, aggregate amount of redemption requirement	$ 42,100
Series D Preferred Stock [Member]
Temporary equity, par or stated value per share	$ 0.001	$ 0.001
Temporary equity, shares authorized	29,285,356	29,285,356
Temporary equity, shares issued	29,285,356	29,285,356
Temporary equity, shares outstanding	29,285,356	29,285,356
Temporary Equity, aggregate amount of redemption requirement	$ 80,000

Leases (Tables)

6 Months Ended

Jun. 30, 2023

Leases [Abstract]

Schedule of information about lease costs

The table below summarizes the Company’s total lease costs included in its unaudited consolidated financial statements, as well as other required quantitative disclosures (

in thousands


	Three Months Ended June 30,						Six Months Ended June 30,
	2023			2022			2023			2022
Operating lease cost	$	558		$	545		$	1,138		$	871
Short-term lease costs		—			(7	)		1			249
Variable leases costs		—			13			5			14
Sublease income		(128	)		—			(238	)		—

Total lease cost	$	430		$	551		$	906		$	1,134

Schedule of present value of operating lease payments

The present value assumptions used in calculating the present value of the lease payments were as follows:


	Three Months Ended June 30, 2023
Weighted-average remaining lease term in years		1.9
Weighted-average discount rate		5.69	%

Schedule of minimum aggregate future operating lease commitments

The minimum aggregate future operating lease commitments at June 30, 2023 are as follows (

in thousands


	Minimum Lease Payments
Remainder of 2023	$	1,084
2024		2,131
2025		1,110
2026		105
2027		0

Total undiscounted lease payments	$	4,430
Less: imputed interest		(222	)

Total operating lease liability		4,208
Less: current portion of operating lease liability		(1,999	)

Operating lease liability, noncurrent	$	2,209

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Operating Activities
Net loss	$ (21,431)	$ (1,016)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	2,066	2,009
Gain on disposal of property and equipment	(14)
Depreciation and amortization	1,439	1,643
Moffitt performance-based common stock award		1,026
Amortization/(Accretion) of premium on short term investments	(468)	176
Change in fair value of contingent consideration liability	876	1,498
Changes in operating assets and liabilities:
Accounts receivable - collaboration agreement	8,478	1,096
Prepaid expenses	652	(1,813)
Other current assets	(347)	(703)
Tax liability	22
Operating lease liabilities	(29)	(481)
Accounts payable	(3,237)	1,012
Change in contingent consideration liability	(1,289)
Accrued compensation and other accrued liabilities	1,002	(1,483)
Other non-current assets	(275)	(1,347)
Deferred revenue	(19,306)	(41,158)
Net cash flows used in operating activities	(31,861)	(39,541)
Investing Activities
Proceeds from maturities of short-term investments	35,500	23,500
Purchase of short-term investments	(15,228)	(24,324)
Proceeds from sale of property and equipment	193
Purchases of property and equipment	(990)	(2,760)
Net cash flows provided by (used in) investing activities	19,475	(3,584)
Financing Activities
Payment of contingent consideration related to Myst milestone	(898)
Payment of deferred IPO costs	(269)
Proceeds from exercise of stock options	86	150
Net cash flows provided by (used in) financing activities	(1,081)	150
Net decrease in cash, cash equivalents and restricted cash	(13,467)	(42,975)
Cash, cash equivalents and restricted cash at beginning of the period	35,113	123,763
Cash, cash equivalents and restricted cash at end of the period	21,646	80,788
Supplemental Disclosure of Cash Flow Information:
Cash paid for income taxes		42
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Accretion of redeemable convertible preferred stock	39	113
Additions to ROU assets obtained from new operating leases		4,120
Equipment purchases included in accrued expenses	186	153
Deferred IPO costs included in accrued expenses	$ 2,286
Issuance of common stock to settle Myst contingent consideration liability		$ 5,000

Income Taxes	6 Months Ended
Income Taxes	Jun. 30, 2023
Income Tax Disclosure [Abstract]
Income taxes	10. Income Taxes The Company did not record federal income tax expense for the six months ended June 30, 2023 and 2022, respectively, as the Company expects to be in a cumulative taxable loss position in 2023 and 2022, and the net deferred tax assets are fully offset by a valuation allowance as it is not more likely than not that the benefit will be realized. The Company recorded a benefit (provision) for state income taxes of $0.1 million and $0.0 million for the six months ended June 30, 2023 and 2022, respectively.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-13

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(h)(2))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//740/tableOfContent

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-14

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 21
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-21

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 270
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482526/740-270-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 17
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-17

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 6.I.5.Q1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479360/740-10-S99-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 11.C)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479360/740-10-S99-2

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482603/740-30-50-2

+ Details

Legal Proceedings - Additional Information (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2023	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Loss contingency reserve for litigation liabilities	$ 0	$ 0

Stockholders' Equity (Tables)

6 Months Ended

Jun. 30, 2023

Stockholders' Equity Note [Abstract]

Summary of shares of common stock reserved for future issuance

Shares of common stock reserved for future issuance, on an

as-if-converted

basis, consisted of the following:


	June 30, 2023		December 31, 2022
Series A redeemable convertible preferred stock		1,408,502		1,408,502
Series B-1 redeemable convertible preferred stock		2,038,903		2,038,903
Series B-2 redeemable convertible preferred stock		3,138,208		3,138,208
Series C redeemable convertible preferred stock		2,241,740		2,241,740
Series D redeemable convertible preferred stock		3,666,526		3,666,526
Stock options, issued and outstanding		2,604,639		1,759,275
Stock options, available for future issuance		159,243		830,774

		15,257,761		15,083,928

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Significant Accounting Policies [Line Items]
Restricted cash	$ 100,000		$ 100,000		$ 400,000
Deferred offering costs	4,400,000		4,400,000		1,900,000
Credit Concentration Risk [Member] \| Accounts Receivable [Member]
Significant Accounting Policies [Line Items]
Accounts receivable	300,000		300,000		8,700,000
Allowance for doubtful accounts receivable	0		$ 0		$ 0
Concentration risk, percentage			100.00%
Accounts receivable write-off	$ 0	$ 0	$ 0	$ 0

Subsequent Events - Additional Information (Detail) - USD ($) $ in Millions	1 Months Ended
	Jul. 31, 2023	Jul. 25, 2023	Jun. 30, 2023	Dec. 31, 2022
Subsequent Event [Line Items]
Common stock, capital shares reserved for future issuance			15,257,761	15,083,928
Subsequent Event [Member] \| Employee Stock Purchase Plan [Member]
Subsequent Event [Line Items]
Share-based compensation arrangement by share-based payment award, number of shares authorized	222,287
Common stock, capital shares reserved for future issuance increase decrease period	10 years
Share-based compensation arrangement by share-based payment award, percentage of outstanding stock maximum	1.00%
Common stock, capital shares reserved for future issuance	666,680
Subsequent Event [Member] \| 2023 Plan [Member]
Subsequent Event [Line Items]
Common stock, capital shares reserved for future issuance increase decrease period	10 years
Share-based compensation arrangement by share-based payment award, percentage of outstanding stock maximum	5.00%
Common stock, capital shares reserved for future issuance	1,889,435
Share-based compensation arrangement by share-based payment award, number of shares available for grant	120,949
Subsequent Event [Member] \| 2021 Plan [Member]
Subsequent Event [Line Items]
Common stock, capital shares reserved for future issuance	712,503
Subsequent Event [Member] \| Myst Therapeutics Inc [Member]
Subsequent Event [Line Items]
Business acquisition contingent liability milestone payment due		$ 3.0

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Income Tax Disclosure [Abstract]
Federal income tax expense	$ 0	$ 0
Benefit (provision) for income taxes	$ 100	$ 0

Subsequent Events	6 Months Ended
Subsequent Events	Jun. 30, 2023
Subsequent Events [Abstract]
Subsequent Events	14. Subsequent Events In July 2023, the Company adopted the Employee Stock Purchase Plan (the “ESPP”), which became effective with the IPO on July 25, 2023. The ESPP was adopted by the Company’s board of directors and stockholders in June, 2023. The ESPP initially provides participating employees with the opportunity to purchase up to an aggregate of 222,287 shares of common stock. The number of shares of common stock reserved for issuance will automatically increase on January 1st of each calendar year for a period of up to ten years, commencing on January 1, 2024 and ending on (and including) January 1, 2033, in an amount equal to the lesser of (i) one percent (1%) of the total number of shares of capital stock outstanding on the last day of the calendar month before the date of the automatic increase, and (ii) 666,680 shares of common stock. Notwithstanding the foregoing, the board may act prior to the first day of any calendar year to provide that there will be no January 1st increase in the share reserve for such calendar year or that the increase in the share reserve for such calendar year will be a lesser number of shares of common stock than would otherwise occur pursuant to the preceding sentence. In Ju ly 2023, the Company adopted the 2023 Equity Incentive Plan (the “2023 Plan”) which became effective with the IPO. The 2023 Plan is a successor to the Company’s 2016 and 2018 Stock Incentive Plans (the “Prior Plans”). The number of shares available for future issuance under the 2023 Plan is the sum of (1) 1,889,435 new shares, plus (2) 712,503 remaining shares of common stock reserved under the Prior Plans that became available for issuance upon the effectiveness of the 2021 Plan, and (3) up to 120,949 Returning Shares (as defined in the 2023 Plan), as such shares become available from time to time. The number of shares of common stock reserved for issuance under the 2023 Plan will automatically increase on January 1 of each year, for a period of ten years, from January 1, 2024 continuing through January 1, 2033, by 5% of the total number of shares of common stock outstanding on December 31 of the preceding calendar year, or a lesser number of shares as may be determined by the Company’s board of directors. Following the effectiveness of the 2023 Plan, no further grants may be made under the Prior Plans; however, any outstanding equity awards granted under the Prior Plans will continue to be governed by the terms of the Prior Plans. On July 25, 2023, the Company concluded its IPO triggering the $3.0 million milestone payment due to the Myst Shareholders. At the Company’s option, this may be made in cash or common stock.

Leases

6 Months Ended

Jun. 30, 2023

Leases [Abstract]

Leases

11. Leases

Operating Leases

The Company leases office space for its corporate headquarters, located in San Diego, California, New York, New York and Ontario, Canada and a laboratory in Ontario, Canada. Operating lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term. In calculating the present value of the lease payments, the Company has elected to utilize its incremental borrowing rate based on the original lease term and not the remaining lease term. The Company determines if an arrangement is a lease by considering whether there is an identified asset, and the contract conveys the right to control its use. Leases with an initial term of 12 months or less are not recorded on the balance sheet. The Company’s lease terms may include options to extend or terminate a lease. If the lease includes

non-lease

components (i.e., common area maintenance) that are paid separately from rent based on actual costs incurred and therefore are not included in the

right-of-use

asset and lease liability but are reflected as an expense in the period incurred.

In July 2018, the Company entered into a lease agreement for approximately 6,500 square feet of office space in New York, New York. The term of the lease is seven years and three months, starting November 1, 2018. The lease requires the Company to share in prorated expenses and property taxes based upon actual amounts incurred. The lease contains escalating rent clauses which require higher rent payments in future years. In September 2022, the Company made the decision to sublease this space and executed a sublease in November, 2022 for the remaining term of the lease. Since the Company is still responsible for making the lease payments, there was no impact to the operating lease liability from the sublease. However, since the sublease payment does not cover the entire lease payment, the carrying value of the operating right of use asset was analyzed and determined to be impaired resulting in a $0.5 million reduction in the operating right of use asset in September 2022.

In January 2019, the Company executed an agreement to lease approximately 6,000 square feet of laboratory space at Carleton University in Ontario, Canada. The initial term of the lease is three years and started in November 2019 at a rate of approximately $0.1 million per year. In November 2022, the lease was extended for a one year period with the option to renew for an additional one year term which the Company does not plan to exercise.

In May 2019, the Company entered into a noncancelable operating lease for approximately 9,423 square feet located at 12 York Street, Ontario, CA. The term of the lease is five years, starting December 1, 2019, and includes one renewal option for a period of five years. The lease requires the Company to share in prorated expenses and property taxes based upon actual amounts incurred. The lease contains escalating rent clauses which require higher rent payments in future years.

In June 2021, the Company entered into a lease agreement for approximately 19,474 square feet of office and laboratory space in San Diego, California. The initial term of the lease is 38 months with one renewal option for a period of three years and commenced in March 2022. The lease requires the Company to share in prorated expenses and property taxes based upon actual amounts incurred. The lease contains escalating rent clauses which require higher rent payments in future years.

The Company recorded rent expense of $0.9 million and $1.1 million for the six months ended June 30, 2023 and 2022, respectively. Cash paid for operating lease liabilities was $1.2 million and $0.7 million for the six months ended June 30, 2023 and 2022, respectively. The table below summarizes the Company’s total lease costs included in its unaudited consolidated financial statements, as well as other required quantitative disclosures (

in thousands


	Three Months Ended June 30,						Six Months Ended June 30,
	2023			2022			2023			2022
Operating lease cost	$	558		$	545		$	1,138		$	871
Short-term lease costs		—			(7	)		1			249
Variable leases costs		—			13			5			14
Sublease income		(128	)		—			(238	)		—

Total lease cost	$	430		$	551		$	906		$	1,134

The present value assumptions used in calculating the present value of the lease payments were as follows:


	Three Months Ended June 30, 2023
Weighted-average remaining lease term in years		1.9
Weighted-average discount rate		5.69	%

The minimum aggregate future operating lease commitments at June 30, 2023 are as follows (

in thousands


	Minimum Lease Payments
Remainder of 2023	$	1,084
2024		2,131
2025		1,110
2026		105
2027		0

Total undiscounted lease payments	$	4,430
Less: imputed interest		(222	)

Total operating lease liability		4,208
Less: current portion of operating lease liability		(1,999	)

Operating lease liability, noncurrent	$	2,209

Agreements - Additional Information (Detail) - USD ($)			1 Months Ended		3 Months Ended		6 Months Ended
Agreements - Additional Information (Detail) - USD ($)	Apr. 30, 2020	Nov. 30, 2019	Apr. 30, 2020	Nov. 30, 2019	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Jun. 01, 2023	Dec. 31, 2022	Dec. 31, 2021
Inflow From Issuance Of Intangible Asset
Additional revenue recognized on change in contract modification						$ 41,915,000	$ 19,306,000	$ 52,633,000
Takeda Agreement [Member]
Inflow From Issuance Of Intangible Asset
Percentage of share of operating profit or loss		30.00%
Transaction price		$ 158,600		$ 158,600							$ 192,600,000
Additional revenue recognized on change in contract modification							31,600,000
Deferred revenue					$ 0		0			$ 19,300,000
Revenue from collaborative arrangement					0	$ 41,900,000	19,300,000	$ 52,600,000
Collaborative arrangement additional consideration receivable for license option					15,000		15,000
Revenue, performance obligation fixed aggregate consideration		80,000,000		80,000,000
Revenue, performance obligation fixed consideration Non refundable upfront payment received				50,000,000
Revenue, performance obligation fixed consideration Non refundable payment received			$ 30,000,000
Estimated compensation earning from project expense sharing		58,600,000		58,600,000							92,600,000
Takeda Agreement [Member] \| Development Program [Member]
Inflow From Issuance Of Intangible Asset
Receivables related to reimbursable costs					$ 300,000		$ 300,000				$ 8,700,000
Takeda Agreement [Member] \| Development Program [Member] \| First Milestone Payment [Member]
Inflow From Issuance Of Intangible Asset
Milestone payment receivable		20,000,000		20,000,000
Transaction price		20,000,000		20,000,000
Takeda Agreement [Member] \| Development Program [Member] \| Second Milestone Payment [Member]
Inflow From Issuance Of Intangible Asset
Milestone payment receivable		15,000,000		15,000,000
Takeda Agreement [Member] \| Development Program [Member] \| Third Milestone Payment [Member]
Inflow From Issuance Of Intangible Asset
Milestone payment receivable		15,000,000		15,000,000
Takeda Agreement [Member] \| Discovery Program [Member]
Inflow From Issuance Of Intangible Asset
Equity purchase commitments by counter party		20,000,000		20,000,000
Takeda Pharmaceutical Company Limited [Member] \| Takeda Agreement [Member]
Inflow From Issuance Of Intangible Asset
Inflow From Issuance Of Intangible Asset	$ 30,000,000	$ 50,000,000
Percentage of share of operating profit or loss		70.00%
Collaborative arrangement additional consideration receivable	$ 15,000		$ 15,000
Takeda Pharmaceutical Company Limited [Member] \| Takeda Agreement [Member] \| Clinical and Regulatory Milestones On Development Program [Member]
Inflow From Issuance Of Intangible Asset
Milestone payment receivable		$ 200,000,000		200,000,000
Takeda Pharmaceutical Company Limited [Member] \| Takeda Agreement [Member] \| Sales Milestones On Development Program [Member]
Inflow From Issuance Of Intangible Asset
Milestone payment receivable		150,000,000		150,000,000
Takeda Pharmaceutical Company Limited [Member] \| Takeda Agreement [Member] \| Clinical and Regulatory Milestones on Licensed Discovery Product [Member]
Inflow From Issuance Of Intangible Asset
Milestone payment receivable		240,000,000		240,000,000
Takeda Pharmaceutical Company Limited [Member] \| Takeda Agreement [Member] \| Sales Milestones on Licensed Discovery Product [Member]
Inflow From Issuance Of Intangible Asset
Milestone payment receivable		$ 300,000,000		$ 300,000,000
H. Lee Moffitt Cancer Center [Member] \| Alliance Agreement [Member]
Inflow From Issuance Of Intangible Asset
Research development and manufacturing services aggregate annual amount									$ 3,500,000
Collaborative arrangement aggregate consideration payable									$ 17,500,000
Number of new stock issued during the period							91,721
H. Lee Moffitt Cancer Center [Member] \| Alliance Agreement [Member] \| Performance Shares [Member]
Inflow From Issuance Of Intangible Asset
Number of new stock issued during the period							91,721
Number of non-vested equity-based payment instruments					366,884		366,884
H. Lee Moffitt Cancer Center [Member] \| Alliance Agreement [Member] \| Sales Based Milestones [Member]
Inflow From Issuance Of Intangible Asset
Other commitment					$ 50,000,000		$ 50,000,000

Property and Equipment, Net - Schedule of Property and Equipment, Net Consist (Detail) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Computer equipment and software	$ 376	$ 376
Laboratory equipment	13,581	12,901
Furniture	743	758
Leasehold improvements	1,308	1,308
Property plant and equipment gross	16,008	15,343
Less accumulated depreciation and amortization	(6,727)	(5,619)
Total property and equipment, net	$ 9,281	$ 9,724

Property and Equipment, Net (Tables)

6 Months Ended

Jun. 30, 2023

Property, Plant and Equipment [Abstract]

Schedule of Property and Equipment Net

Property and equipment, net consist of the following (

in thousands


	June 30, 2023			December 31, 2022
Computer equipment and software	$	376		$	376
Laboratory equipment		13,581			12,901
Furniture		743			758
Leasehold improvements		1,308			1,308

		16,008			15,343
Less accumulated depreciation and amortization		(6,727	)		(5,619	)

Total property and equipment, net	$	9,281		$	9,724

Leases - Schedule of Minimum Aggregate Future Operating Lease Commitments (Detail) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Lessee, Operating Lease, Liability, to be Paid, Fiscal Year Maturity [Abstract]
Remainder of 2023	$ 1,084
2024	2,131
2025	1,110
2026	105
2027	0
Total undiscounted lease payments	4,430
Less: imputed interest	(222)
Total operating lease liability	4,208
Less: current portion of operating lease liability	(1,999)	$ (1,961)
Operating lease liability, noncurrent	$ 2,209	$ 3,205

Accrued Expenses and Other Current Liabilities (Tables)

6 Months Ended

Jun. 30, 2023

Accrued Liabilities and Other Liabilities [Abstract]

Schedule of Accrued Liabilities and Other Current Liabilities

Accrued expenses and other current liabilities consist of the following

(in thousands):


	June 30, 2023		December 31, 2022
Research and development expense	$	8,534	$	6,688
Professional and consulting expense		3,104		1,170
Compensation		2,496		2,366
Tax liability, current		83		252
Contingent consideration, current		2,250		3,791
Other current liabilities		—		20

Total accrued expenses and other current liabilities	$	16,467	$	14,287

Net Earnings (Loss) per Share - Schedule of Dilutive Securities Excluded From Computation of Diluted Net Loss Per Share (Detail)	6 Months Ended
	Jun. 30, 2023 shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	15,279,998
Redeemable Convertible Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	12,493,879
Restricted Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	181,480
Options to purchase common stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	2,604,639

Property and Equipment, Net

6 Months Ended

Jun. 30, 2023

Property, Plant and Equipment [Abstract]

Property and Equipment, Net

4. Property and Equipment, Net

Property and equipment, net consist of the following (

in thousands


	June 30, 2023			December 31, 2022
Computer equipment and software	$	376		$	376
Laboratory equipment		13,581			12,901
Furniture		743			758
Leasehold improvements		1,308			1,308

		16,008			15,343
Less accumulated depreciation and amortization		(6,727	)		(5,619	)

Total property and equipment, net	$	9,281		$	9,724

Property and equipment depreciation and amortization expense for the three months ended June 30, 2023 and 2022, was $0.7 million and $0.9 million, respectively and the six months ended June 30, 2023 and 2022, was $1.4 million and $1.6 million, respectively.

Fair Value of Financial Assets and Liabilities - Schedule of unobservable input of contingent consideration valuation (Detail) - Contingent consideration [Member] $ in Thousands	Jun. 30, 2023 USD ($) yr	Dec. 31, 2022 USD ($) yr
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value of financial liabilities \| $	$ 4,683	$ 5,994
Measurement input likelihood of occurrence [Member] \| Valuation technique discounted cash flow [Member] \| Minimum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration input range	20	20
Measurement input likelihood of occurrence [Member] \| Valuation technique discounted cash flow [Member] \| Maximum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration input range	75	100
Measurement input discount rate [Member] \| Valuation technique discounted cash flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration input range	22	22
Measurement input expected term [Member] \| Valuation technique discounted cash flow [Member] \| Minimum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration input range	0.25	0.25
Measurement input expected term [Member] \| Valuation technique discounted cash flow [Member] \| Maximum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration input range	2.5	2.75

Agreements (Tables)

6 Months Ended

Jun. 30, 2023

Collaborative Arrangement Disclosure [Abstract]

Schedule Of Transaction Price Allocated To Programs Performance Obligation

The Company determined that the notice of termination on June 13, 2022 represented a modification of the arrangement under ASC 606 and that the transaction price should be updated and

re-allocated

to the Development Program Performance Obligation and the Discovery Program Performance Obligation based on their standalone selling prices, as follows:


Performance Obligations	Price Pre-Modification	Price at Modification
Development Program	$166.3 million	$134.3 million
Discovery Program	$26.3 million	$21.2 million
Total	$192.6 million	$155.5 million

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 21,530	$ 34,731
Restricted cash	116	382
Short-term investments	27,706	47,330
Accounts receivable - collaboration agreement	250	8,728
Prepaid expenses	4,429	5,081
Other current assets	2,096	1,749
Total current assets	56,127	98,001
Other assets, noncurrent	5,661	2,582
Operating lease right of use assets	3,702	4,631
Property and equipment, net	9,281	9,724
Total assets	74,771	114,938
Current liabilities:
Accounts payable	198	3,435
Accrued expenses and other current liabilities	16,467	14,287
Operating lease liability, current	1,999	1,961
Deferred revenue, current	0	15,144
Total current liabilities	18,664	34,827
Deferred revenue, noncurrent	0	4,162
Operating lease liability, noncurrent	2,209	3,205
Other liabilities, noncurrent	2,520	2,267
Total liabilities	23,393	44,461
Redeemable convertible preferred stock
Preferred stock ,shares authorized, issued and outstanding	171,983	171,944
Stockholders' deficit
Common stock, $0.001 par value; 147,892,358 shares authorized, 3,029,258 and 2,915,757 shares issued and outstanding as of June 30, 2023 and December 31, 2022, respectively	3	3
Additional paid-in capital	22,614	20,501
Accumulated other comprehensive loss	(233)	(413)
Accumulated deficit	(142,989)	(121,558)
Total stockholders' deficit	(120,605)	(101,467)
Total liabilities, redeemable convertible preferred stock and stockholders'	74,771	114,938
Series A Preferred Stock [Member]
Redeemable convertible preferred stock
Preferred stock ,shares authorized, issued and outstanding	8,643	8,643
Series B-1 redeemable convertible preferred stock [Member]
Redeemable convertible preferred stock
Preferred stock ,shares authorized, issued and outstanding	12,611	12,611
Series B-2 redeemable convertible preferred stock [Member]
Redeemable convertible preferred stock
Preferred stock ,shares authorized, issued and outstanding	28,860	28,860
Series C Preferred Stock [Member]
Redeemable convertible preferred stock
Preferred stock ,shares authorized, issued and outstanding	42,100	42,100
Series D Preferred Stock [Member]
Redeemable convertible preferred stock
Preferred stock ,shares authorized, issued and outstanding	$ 79,769	$ 79,730

Agreements

6 Months Ended

Jun. 30, 2023

Agreements [Abstract]

Agreements

6. Agreements

Takeda Pharmaceutical Company Limited

Collaboration Agreement

In November 2019, the Company entered into a discovery, collaboration and license agreement (“Takeda Agreement”) with Millennium Pharmaceuticals, Inc. (also known as Takeda Oncology), a wholly owned subsidiary of Takeda Pharmaceutical Company Limited (Takeda). Under the Takeda Agreement, the Company agreed to collaborate with Takeda to

co-develop

and

co-commercialize

TBio-6517 (also known as

RIVAL-01)

(“Development Program”) and to conduct discovery programs to identify additional novel product candidates based on its vaccinia virus platform for independent development (“Discovery Program”).

Under the Takeda Agreement, the Company granted Takeda and its affiliates a worldwide, irrevocable,

non-transferable,

co-exclusive,

sublicensable license under certain of the Company’s

know-how

and patent rights (“Turnstone Technology”) to make, use, sell, offer for sale, develop, manufacture, and commercialize, or otherwise exploit TBio-6517 (“Licensed Compound”) and products containing TBio-6517 (“Takeda Licensed Products”) in all fields. Takeda granted the Company and the Company’s affiliates an irrevocable,

non-transferable,

non-exclusive,

sublicensable license under certain

know-how

and patent rights of Takeda (“Takeda Technology”) to make, use, sell, offer for sale, develop, manufacture, and commercialize, or otherwise exploit the Licensed Compound and Takeda Licensed Products in all fields in accordance with joint development, commercialization, and medical affairs plans under the Takeda Agreement. Under the Takeda Agreement, the Company also granted to Takeda and its affiliates a worldwide,

non-transferable,

non-exclusive,

sublicensable license under Turnstone Technology to conduct joint discovery and research activities in all fields in accordance with joint research and discovery plans. Under the Takeda Agreement, Takeda granted the Company a license to Takeda Technology to conduct discovery and research activities in all fields in accordance with joint research and discovery plans. The Company also granted to Takeda and its affiliates an exclusive option to obtain a worldwide, irrevocable,

non-transferable,

exclusive, sublicensable license under Turnstone Technology to make, use, sell, offer for sale, develop, manufacture, and commercialize, or otherwise exploit (i) selected discovery virus candidates generated and evaluated by the parties under a joint discovery program (“Selected Discovery Candidates”), and (ii) any corresponding licensed products containing a Selected Discovery Candidate (“Licensed Discovery Products”). Takeda may exercise this option with respect to two virus candidates and within a specified option exercise period. The Company granted Takeda and its affiliates a

non-exclusive,

perpetual, irrevocable, worldwide, sublicensable and fully

paid-up

license under certain of the Company’s

know-how

and patents relating to manufacturing improvements developed under the Takeda Agreement solely for use in connection with the manufacture of products that do not comprise or incorporate, and that are not based on, an oncolytic virus. Takeda granted the Company and the Company’s affiliates a

non-exclusive,

perpetual, irrevocable, worldwide, sublicensable and fully

paid-up

license under certain of Takeda’s

know-how

and patents relating to manufacturing improvements developed under the Takeda Agreement solely for use in connection with the manufacture of any and all products. With respect to discovery virus candidates for which Takeda does not exercise its option, Takeda granted the Company a

non-exclusive,

perpetual, worldwide, sublicensable and royalty-bearing license under certain of its

know-how

and patents that is necessary or reasonably useful for the exploitation of such declined discovery virus candidates (“Declined Candidate License”).

Responsibilities for the development of Licensed Compounds and Takeda Licensed Products are delineated pursuant to a joint development plan under the terms of the Takeda Agreement. The Company will be responsible for all activities under the joint development plan prior to completion of a Phase 2a clinical trial and Takeda will be responsible for all activities in the joint development plan upon and after completion of the Phase 2a clinical trial. Responsibilities relating to manufacturing, medical affairs, and commercialization of Licensed Compounds and Takeda Licensed Products are delineated

pursuant to a manufacturing working plan, joint medical affairs plan and joint commercialization plan, respectively. The Company has the right to reduce or

opt-out

of its share of responsibilities for costs and expenses of certain development or commercialization activities for the Takeda Licensed Compounds and Takeda Licensed Products. Responsibilities for the discovery and research of Selected Discovery Candidates are delineated pursuant to joint discovery and research plans under the terms of the Takeda Agreement.

Under the Takeda Agreement, Takeda paid the Company a

non-refundable

payment of $50.0 million in November, 2019 and an additional

non-refundable

payment of $30.0 million in April, 2020, for the option to license up to two Selected Discovery Candidates, with additional consideration of $15.0 million to be paid by Takeda to the Company for each exercise of such option.

Under the Takeda Agreement, the Company has the right to reduce its share of funding obligations with respect to development activities for the Licensed Compound and Takeda Licensed Products (the “Development

Opt-Down

Right”), or to

opt-out

of all further funding obligations with respect to development activities for the Licensed Compound and Takeda Licensed Products (the “Development

Opt-Out

Right”). Unless and until the Company exercises the Development

Opt-Down

Right, the parties will share evenly in any operating profits or losses with respect to joint development activities, joint medical affairs activities, and joint commercialization activities. If the Company exercises its Development

Opt-Down

Right, then starting from the effective date of the exercise of the right, Takeda will bear (and be entitled to) 70% and the Company will bear (and be entitled to) 30% of the operating profits or losses with respect to joint development activities, joint medical affairs activities, and joint commercialization activities. Takeda is obligated to pay the Company (i) up to $200.0 million in aggregate upon achievement of certain clinical and regulatory milestones for the first Takeda Licensed Product to achieve the applicable development milestone event, (ii) up to $150.0 million in aggregate for

one-time

payments upon achievement of certain sales milestones for each Takeda Licensed Product, (iii) up to $240.0 million in aggregate (if Takeda exercises both options to Selected Discovery Candidates) upon achievement of certain clinical and regulatory milestones for the first Takeda Licensed Discovery Product to achieve applicable development milestone events, and (iv) up to $300.0 million in aggregate (if Takeda exercises both options to Selected Discovery Candidates) for

one-time

payments upon achievement of certain sales milestones for a Licensed Discovery Product. If the Company exercises its Development

Opt-Out

Right for the Takeda Licensed Products, then in lieu of the profit and loss share arrangement described above, the Company is entitled to receive tiered

low-

to high- teen percentage royalties on net sales of all Takeda Licensed Products by the Company or the Company’s sublicensees during the royalty term, which commences on the first commercial sale of a Takeda Licensed Product in a country and ends on the later of the expiration of all licensed patents covering such Licensed Product in such country or ten years after the date of the first commercial sale in such country (“Royalty Term”). For Licensed Discovery Products, the Company is entitled to receive tiered high-single digit to

low-teen

percentage royalties on net sales of all Licensed Discovery Products by the Company or the Company’s sublicensees during the Royalty Term. Royalty payments are subject to customary reductions.

Takeda has the right to terminate for convenience as follows: (i) prior to the expiration of the option exercise period related to a Discovery Virus Candidate, Takeda may terminate the Takeda Agreement related to such Discovery Virus Candidate and the Discovery Program with 90 days’ notice, (ii) prior to any commercial sale, Takeda may terminate the Takeda Agreement either in its entirety or on a

compound-by-compound

region-by-region

basis, with six months’ notice and (iii) after a commercial sale, Takeda may terminate the Takeda Agreement either in its entirety or on a

compound-by-compound

region-by-region

basis, with 12 months’ notice.

Termination of Development Program

On June 13, 2022, Takeda provided six months’ written notice to terminate the Development Program in accordance with its termination for convenience rights, with such termination being effective as of December 13, 2022. During the six months’ notice period, the Company was obligated to continue providing the necessary Development Program services to wind down the program. Upon the effective termination date of December 13, 2022, Takeda’s

co-exclusive

license to TBio-6517 terminated and the Company is no longer obligated to pursue development of TBio-6517.

Termination of Discovery Program

On January 6, 2023, Takeda provided six months’ written notice to terminate the remainder of the Takeda Agreement, with such termination being effective as of July 6, 2023 (“Effective Termination Date”). On the Effective Termination Date, all options and licenses granted under the Takeda Agreement will terminate (except for the Declined Candidate License) and Takeda will grant the Company a

non-exclusive

license under the patent rights and

know-how

controlled by Takeda as of the Effective Termination Date necessary for the Company to exploit the Licensed Compound and Takeda Licensed Products in the form existing as of the Effective Termination Date for any use worldwide, subject to a royalty to be agreed upon by Takeda and the Company. As of March 31, 2023, the Company ceased all work under the Takeda Agreement and the Company has concluded that there are no remaining estimated services associated with the obligations under the Takeda Agreement

as of June

30, 2023

Accounting Analysis

The Company assessed the promised goods and services under the Takeda Agreement in accordance with ASC 606, and determined that, at inception, the Takeda Agreement includes the following performance obligations: (i) research, development and manufacturing services under the Development Program for the completion of clinical trials through Phase 2a for

RIVAL-01

and a

co-exclusive

license to exploit

RIVAL-01

(“Development Program Performance Obligation”); and (ii) research and development services under the Discovery Program to identify and optimize four Selected Discovery Candidates for further development (“Discovery Program Performance Obligation”). The individual promises under the Development Program including research, development, manufacturing for clinical trials, and the

co-exclusive

license to

RIVAL-01

are not individually distinct as they represent inputs into a combined output of advancing

RIVAL-01

through the Phase 2a clinical trial. Therefore, all promises under the Development Program represent a single performance obligation. Similarly, the research and development services under the Discovery Program represent a single research program aimed at generating four Selected Discovery Candidates and therefore represents a single performance obligation. The Development Program promises are distinct from the promises under the Discovery Program, as the benefits under each program are separately identifiable. Each program has a separate work plan and the promises to be provided under the Development Program do not relate to the promises to be provided under the Discovery Program.

The Company concluded that Takeda’s license options under the Discovery Program do not represent material rights, and therefore are not performance obligations, as the Company is entitled to an additional $15.0 million payment for each license option exercised, which approximates the estimated standalone selling price of the underlying license.

The total transaction price at contract inception is $158.6 million, comprised of the following components:

•

Fixed consideration of $80.0 million including a

non-refundable

up-front

payment of $50.0 million in November, 2019 and another

non-refundable

payment of $30.0 million that was due on April 1, 2020 and received in April 2020.

•

Variable consideration related to the expense sharing under the Development Program. These amounts are determinable based on the Development Program plan and budget, and the Company has a contractual right to the payment of costs incurred under the agreed upon plan. Consistent with the expected value method, the Company estimated that it will receive $58.6 million under the expense sharing through the completion of the Phase IIa clinical trial. The Company has concluded that these amounts do not require a constraint and are included in the transaction price at inception. The Company has evaluated this estimate at each reporting date and updated the estimate based on information available.

•

Variable consideration for the development milestones under the Development Program. The Company uses the most likely amount method to value this variable consideration as there are only two possible outcomes of achieving the individual milestones. Under the Development Program, the first milestone of $20.0 million is due upon acceptance of the IND by the FDA. At inception, the Company concluded that achievement of this milestone was highly probable and therefore the $20.0 million was included in the transaction price and was received in March 2020. The second milestone of $15.0 million under the Development Program is due upon the initiation of the first Phase 2 clinical trial for a licensed product. The Company has determined that the most likely amount is $15.0 million, however, the Company will not include this $15.0 million milestone in the transaction price until it becomes probable that a significant reversal of cumulative revenue will not occur.

Additional consideration to be paid to the Company includes development and sales milestones, profit and loss share, royalties and option exercise payments. These additional payments are achievable only after the completion of the Phase 2a clinical trial under the Development Program or exercise of the license options under the Discovery Program and therefore are excluded from the transaction price. Additionally, Takeda’s equity purchase commitments of up to $20.0 million are at fair value and therefore no

non-cash

consideration has been included as a component of the transaction price.

The Company allocated the transaction price to the separate performance obligations based on their relative standalone selling prices. The Company determined the standalone selling price of the Development Program Performance Obligation based on the costs incurred to develop

RIVAL-01

plus the estimated costs to perform the research, development and manufacturing services through the completion of the Phase 2a clinical trial, inclusive of a reasonable profit margin. The Company determined the standalone selling price of the Discovery Program Performance Obligation based on the estimated costs to discover and research four Selected Discovery Candidates, inclusive of a reasonable profit margin. Significant inputs used to determine the standalone selling prices of the performance obligations include the length of time required, the internal hours expected to be incurred on the services, and the amount of third-party expenses that will be incurred to complete the performance obligations.

The Company recognizes the amounts associated with these performance obligations on a proportional performance basis over the contract term using input-based measurements of total cost of research and development incurred to estimate the proportion performed as compared to the estimated total cost and remeasures its progress towards completion at the end of each reporting period.

As of December 31, 2021 the transaction price was updated to $192.6 million to reflect an increase in the variable consideration related to the expense sharing under the Development Program from $58.6 million at inception to $92.6 million.

The Company determined that the notice of termination on June 13, 2022 represented a modification of the arrangement under ASC 606 and that the transaction price should be updated and

re-allocated

to the Development Program Performance Obligation and the Discovery Program Performance Obligation based on their standalone selling prices, as follows:


Performance Obligations	Price Pre-Modification	Price at Modification
Development Program	$166.3 million	$134.3 million
Discovery Program	$26.3 million	$21.2 million
Total	$192.6 million	$155.5 million

Additionally, the Company updated its measure of progress for each performance obligation as of the modification date and recorded a cumulative adjustment that increased collaboration revenue by $31.6 million on the partially satisfied remaining performance obligations, as the remaining services to be performed under each of the performance obligations are not distinct from the services prior to the modification.

Costs incurred relating to the Takeda Agreement consist of internal and external research and development costs, which primarily include salaries and benefits, lab supplies, and preclinical research studies. All of these costs are included in research and development expenses in the Company’s unaudited condensed consolidated statements of operations and comprehensive income (loss) during the six months ended June 30, 2023 and 2022.

The deferred revenue balance in connection with the Takeda Agreement as of June 30, 2023 and December 31, 2022 was $0.0 million and $19.3

million, respectively, which is classified as either current or noncurrent in the accompanying unaudited condensed consolidated balance sheet based on the periods the performance obligations are expected to be performed. The Company recognized the remaining deferred revenue balance during the three months ended March 31, 2023 as the Company concluded that there are no remaining estimated services to be performed associated with the obligations under the Takeda Agreement. The Company recognized collaboration revenue related to the Takeda Agreement for the six months ended June 30, 2023 and 2022 of $

19.3 million and $52.6 million, respectively, and for the three months ended June 30, 2023 and 2022 of $0.0 million and $41.9 million, respectively. Receivables related to reimbursable costs expected to be received from Takeda for research and development services performed under the Development Program at June 30, 2023 and December 31, 2022 were $0.3 million and $8.7 million, respectively.

H. Lee Moffitt Cancer Center

Master Collaboration Agreement

In January 2021, the Company entered into an amended and restated master collaboration agreement (the “Moffitt Agreement”), with Moffitt, to amend a then-existing master collaboration agreement from November 2019, as amended March 2020, between Moffitt and the Company’s now wholly-owned subsidiary, Myst Therapeutics LLC, with the intent to continue to work collaboratively in the research of cancer immunotherapies.

Each party granted the other party a right to use its research materials for performance of the research plans agreed to by the parties (the “Research Plans”). Each party granted the other party a

non-exclusive,

worldwide, sublicensable, perpetual, irrevocable, royalty-free license under all inventions invented in performance of a Research Plan and invented jointly by the Company and Moffitt (the “Joint Inventions”) (with certain exclusions) to make, use, sell, offer for sale, import products and services and/or otherwise practice such inventions.

The Company granted Moffitt a royalty free,

non-sublicensable,

non-transferable,

perpetual,

non-exclusive

license to use and practice certain inventions invented solely by the Company in the performance of a Research Plan for its internal

non-commercial

research purposes.

Moffitt granted the Company (i) a royalty-free, sublicensable,

non-transferable,

perpetual,

non-exclusive

license to use and practice certain inventions invented solely by Moffitt in the performance of a Research Plan (“Moffitt Inventions”), (a) for internal,

non-commercial

research purposes outside the field of ACT and/or (b) to research, develop, make, use, sell, offer to sell, or import products and/or services in the field of ACT and (ii) a royalty free, sublicensable,

non-transferable,

perpetual,

non-exclusive

license to use and practice certain inventions invented in performance of a Research Plan or through the use of specified Moffitt research materials.

Moffitt granted the Company an option to obtain, with terms to be negotiated in good faith under commercially reasonable terms, a royalty-bearing, sublicensable exclusive license in the Moffitt Inventions, the TCR Inventions, and/or Moffitt’s interest in Joint Inventions. The Company can exercise this option at any time within six months after Moffitt informs the Company of any new invention, and upon the Company’s exercise, the parties will have a period of six months to negotiate the terms of such exclusive license.

The Moffitt Agreement will expire upon the later of (i) four years from the effective date of the Moffitt Agreement or (ii) the termination or expiration of all Research Plans in effect under the Moffitt Agreement, unless extended upon mutual written agreement of the parties. Either party may terminate the Moffitt Agreement for cause upon any uncured breach by the other party or upon the insolvency of the other party.

Moffitt Alliance Agreement

In June 2022, the Company entered into a life science alliance agreement with Moffitt (the “Alliance Agreement”), in order to further expand the Company’s relationship and support the Company’s existing agreements with Moffitt (the “Underlying Agreements”). Pursuant to the Alliance Agreement, the Company will have priority access to Moffitt’s scientific research, manufacturing, and clinical capabilities for the development of novel TIL therapies, including expedited clinical trial activation, enhanced patient screening and data sharing, access to Moffitt’s cellular therapies research and development infrastructure, expanded molecular data sets and biospecimens for research, and allocated cGMP manufacturing capacity for the Company’s product candidates.

Under the Alliance Agreement, the Company is obligated to use commercially reasonable efforts to further develop TIL Products, to manufacture TIL Products, to obtain regulatory approval for at least one TIL Product in the United States and to commercialize TIL Products in all countries in which regulatory approval for a TIL Product has been obtained. For purposes of the Alliance Agreement, TIL Product means any pharmaceutical, biopharmaceutical, or biotechnology TIL product that has been developed by us or Moffitt and is advanced into clinical development under an IND sponsored by Moffitt.

Pursuant to the Alliance Agreement, the Company agreed to pay to Moffitt a total amount of at least $

17.5

million (the “Alliance Funding Amount”), for research, development and manufacturing related services that will be paid equally over five years on June 1st of each year starting on June 1, 2023. The Alliance Funding Amount will be calculated annually at the conclusion of each payment period, and, to the extent the Company’s annual aggregate payments to Moffitt of $

3.5

million exceeds the applicable annual installment amount, the Company will receive a reduction in the amount due for future installment payments based on a predetermined formula agreed to by the parties. To the extent the aggregate annual payments are less than $

3.5

million, the Company will prepay the remaining amount due.

In connection with the execution of the Alliance Agreement, the Company issued Moffitt 91,721 shares of its common stock. As partial consideration under the Alliance Agreement, the Company also agreed to issue Moffitt an additional 366,884

shares of its common stock in the aggregate upon the satisfaction of certain clinical and regulatory milestones with respect to TIL Products. The issuances of common stock are treated as performance-based stock awards. On February 27, 2023,

91,721 shares were issued due to the achievement of the milestone related to the start of the Phase 1 trial. In addition, upon achievement of certain thresholds for aggregate net sales of all TIL Products, the Company is required to make tiered sales-based milestones payments to Moffitt of up to an aggregate of $

50.0

million. With respect to each of the equity and sales milestones described above, TIL products include any pharmaceutical, biopharmaceutical or biotechnology TIL product that is developed by the Company or Moffitt and is advanced into clinical development under an IND sponsored by Moffitt.

Unless earlier terminated, the Alliance Agreement will remain in effect for a term of five years and may be extended for additional periods upon the mutual written consent of both parties. Either party may terminate the Alliance Agreement in the event of (i) the other party’s material breach of the Alliance Agreement that remains uncured after ninety days of receiving written notice of such breach (or in the case of breach of payment obligations, within ten days), (ii) the other party’s insolvency and (iii) a pandemic event resulting in government lockdowns or orders that legally compel such party to cease operations or that result in material disruptions in the available workforce and prevents such party from performing its contractual obligations for a period of more than six months. At any time after June 1, 2025, either party may terminate the Alliance Agreement without cause upon sixty days prior written notice to the other party (a “Termination for Convenience”). Upon a Termination for Convenience, the terminating party shall pay to the other party a termination fee in an amount equal to a low double digit percentage of the then remaining Alliance Funding Amount. Termination or expiry of one or more Underlying Agreements does not affect the term of the Alliance Agreement, which will continue to apply to the remaining ongoing Underlying Agreements.

Net Earnings (Loss) per Share

6 Months Ended

Jun. 30, 2023

Earnings Per Share [Abstract]

Net earnings (loss) per share

12. Net Earnings (Loss) per Share

The following table sets forth the computation of the basic and diluted net loss per share (

in thousands, except share and per share data


	Three Months Ended June 30,						Six Months Ended June 30,
	2023			2022			2023			2022
Net income (loss)	$	(21,499	)	$	11,600		$	(21,431	)	$	(1,016	)
Less: accretion of Preferred Stock to redemption value		(19	)		(57	)		(39	)		(114	)
Less: undistributed earnings allocable to participating securities		—			(10,355	)		—			—

Net income (loss) attributable to common stockholders, basic and diluted	$	(21,518	)	$	1,188		$	(21,470	)	$	(1,130	)

Weighted-average number of basic shares used in computing net earnings (loss) per share		2,847,675			2,355,553			2,817,008			2,317,631
Effect of dilutive securities
Stock options		—			442,002			—			—
Restricted stock		—			29,683			—			—
Redeemable converted preferred stock		—			—			—			—

Weighted-average number of diluted shares used in computing net earnings (loss) per share		2,847,675			2,827,238			2,817,008			2,317,631

Net earnings (loss) per share
Basic	$	(7.56	)	$	0.50		$	(7.62	)	$	(0.49	)

Diluted	$	(7.56	)	$	0.42		$	(7.62	)	$	(0.49	)

The following outstanding potentially dilutive shares were excluded from the computation of diluted net loss per share attributable to common stockholders for the six months ended June 30, 2023, because including them would have been anti-dilutive (on an

as-converted

basis).


Restricted stock			181,480
Options to purchase common stock			2,604,639
Redeemable convertible preferred stock			12,493,879

Total			15,279,998

Property and Equipment, Net - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Property, Plant and Equipment [Abstract]
Property and equipment depreciation and amortization expense	$ 700	$ 900	$ 1,439	$ 1,643

Equity Based Compensation

6 Months Ended

Jun. 30, 2023

Share-Based Payment Arrangement [Abstract]

Equity Based Compensation

9. Equity Based Compensation

2018 Equity Incentive Plan

In December 2018, the Company adopted the 2018 Equity Incentive Plan (the “2018 Plan”) which provides for the Company to grant incentive stock options or nonqualified stock options for the purchase of common stock, or restricted shares, to employees, members of the board of directors and consultants of the Company. The Company assumed all of the outstanding options under the amended and restated Equity Incentive Plan of Turnstone Biologics Inc. dated October 1, 2016 (the “Prior Plan”) in connection with the corporate reorganization in December 2018. However, there were no changes to the terms of the options requiring modification accounting.

All options granted under the 2018 Plan will have an exercise price, a vesting period determine by the Company’s board of directors and

ten-year

term as determined and approved by the Company’s board of directors (the board of directors may delegate authority to one of the boards’ committees) at the time of grant. The terms and conditions of the restricted shares are determined by the board of directors at the grant date.

The majority of grants outstanding have been approved with a four-year vesting schedule with 25% vesting after one year and the remainder vesting evenly over the remaining 36 months. The total number of shares of common stock that may be issued under the 2018 Plan was 35,000,000 shares when the 2018 Plan was adopted. As of June 30, 2023, 159,243 shares were available to be issued under the 2018 Plan.

A summary of the stock option activity under the 2018 Plan is as follows:


	Number of Shares Underlying Outstanding Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value (in thousands)
Outstanding — December 31, 2021		1,759,275		$	7.26		7.2	$	6,912

Options granted		874,879		$	11.02
Options exercised		(60,574	)	$	2.47
Options canceled/forfeited		(22,679	)	$	8.14

Outstanding — June 30, 2022		2,550,901		$	8.62		7.5	$	6,464

Exercisable — June 30, 2022		1,126,388		$	6.07		5.7	$	5,718

Vested and expected to vest — June 30, 2022		2,550,901		$	8.62		7.5		6,464

Outstanding — December 31, 2022		2,529,982		$	8.86		6.8	$	5,886

Options granted		189,365		$	16.45
Options exercised		(21,784	)	$	3.91
Options canceled/forfeited		(92,924	)	$	10.46

Outstanding — June 30, 2023		2,604,639		$	9.42		6.8	$	18,605

Exercisable — June 30, 2023		1,622,615		$	7.82		5.7	$	14,100

Vested and expected to vest — June 30, 2023		2,604,639		$	9.42		6.8	$	18,605

The fair value of each stock option granted to employees and directors was estimated on the date of grant using the Black-Scholes option-pricing model, with the following range of assumptions:


	Six Months Ended June 30,
	2023	2022
Risk-free interest rate	3.89% - 4.48%	1.48% - 3.00%
Expected term (in years)	6.09 - 6.20	5.69 - 5.92
Dividend yield	0%	0%
Volatility	85.8% - 86.2%	86.8% - 87.2%
Exercise price of stock options grante d	$11.18 - $16.53	10.94 - 11.18

The expense related to awards granted to employees and directors was $2.1 million and $2.0 million for the six months ended June 30, 2023, and 2022, respectively. The weighted-average grant date Black Scholes fair market value of options granted to employees, directors and consultants during the six months ended June 30, 2023, and 2022 was $12.23 per share and $7.90 per share, respectively.

Stock-based compensation expense for all stock awards included in the Company’s statements of operations are as follows (

in thousands


	Three Months Ended June 30,				Six Months Ended June 30,
	2023		2022		2023		2022
Research and development	$	507	$	542	$	1,009	$	1,063
General and administrative		567	$	505		1,057		946

Total stock-based compensation	$	1,074	$	1,047	$	2,066	$	2,009

As of June 30, 2023, the Company had unrecognized stock-based compensation expense of $8.9 million, related to stock options, which is expected to be recognized over a weighted-average period of 2.7 years.

Restricted Stock

In December 2020, Langer received 725,920 shares as payment related to the Myst Merger Agreement. Of the total issued, the Company restricted 362,960 shares to vest over a four-year period in equal annual installments. As of June 30, 2023, 181,480 shares remain unvested, and the Company had $1.4 million in unrecognized

stock-based

compensation expense related to unvested restricted stock which is expected to be recognized evenly over 1.5 years.

Legal Proceedings	6 Months Ended
Legal Proceedings	Jun. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Legal Proceedings	13. Legal Proceedings The Company is not a party to any material legal matters or claims and does not have contingency reserves established for any litigation liabilities as of the six months ended June 30, 2023 and the year ended December 31, 2022.

Stockholders' Equity - Summary Of Shares Of Common Stock Reserved For Future Issuance (Detail) - shares	Jun. 30, 2023	Dec. 31, 2022
Class of Stock [Line Items]
Common stock reserved for future issuance	15,257,761	15,083,928
Vested Employee Stock Option [Member]
Class of Stock [Line Items]
Common stock reserved for future issuance	2,604,639	1,759,275
Unvested Employee Stock Option [Member]
Class of Stock [Line Items]
Common stock reserved for future issuance	159,243	830,774
Series A redeemable convertible preferred stock [Member]
Class of Stock [Line Items]
Common stock reserved for future issuance	1,408,502	1,408,502
Series B-1 redeemable convertible preferred stock [Member]
Class of Stock [Line Items]
Common stock reserved for future issuance	2,038,903	2,038,903
Series B-2 redeemable convertible preferred stock [Member]
Class of Stock [Line Items]
Common stock reserved for future issuance	3,138,208	3,138,208
Series C redeemable convertible preferred stock [Member]
Class of Stock [Line Items]
Common stock reserved for future issuance	2,241,740	2,241,740
Series D redeemable convertible preferred stock [Member]
Class of Stock [Line Items]
Common stock reserved for future issuance	3,666,526	3,666,526

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 505
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-Name Accounting Standards Codification
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Reference 2: http://www.xbrl.org/2003/role/recommendedDisclosureRef
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Reference 11: http://www.xbrl.org/2003/role/disclosureRef
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-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-2

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-03(i)(2))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479886/946-10-S99-3

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-03(i)(1))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479886/946-10-S99-3

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-03(i)(2)(i))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479886/946-10-S99-3

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.6-03(i)(2)(ii))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479886/946-10-S99-3

+ Details

Equity Based Compensation - Schedule of Fair Value Assumption of Stock Option Activity (Detail) - $ / shares	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Schedule Of Share Based Payment Award Stock Options Valuation Assumptions [Line Items]
Risk-free interest rate, Minimum	3.89%	1.48%
Risk-free interest rate, Maximum	4.48%	3.00%
Dividend yield	0.00%	0.00%
Volatility, Minimum	85.80%	86.80%
Volatility, Maximum	86.20%	87.20%
Minimum [Member]
Schedule Of Share Based Payment Award Stock Options Valuation Assumptions [Line Items]
Expected term (in years)	6 years 1 month 2 days	5 years 8 months 8 days
Exercise price of stock options granted	$ 11.18	$ 10.94
Maximum [Member]
Schedule Of Share Based Payment Award Stock Options Valuation Assumptions [Line Items]
Expected term (in years)	6 years 2 months 12 days	5 years 11 months 1 day
Exercise price of stock options granted	$ 16.53	$ 11.18

Equity Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended
	Dec. 31, 2020	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Allocated share based compensation expense		$ 1,074	$ 1,047	$ 2,066	$ 2,009
Share-based compensation arrangement by share-based payment award, options, grants in period, weighted average grant date fair value				$ 12.23	$ 7.9
Share-based payment arrangement, non-vested award, option, cost not yet recognized, amount		$ 8,900		$ 8,900
Share-based payment arrangement, non-vested award, cost not yet recognized, period for recognition				2 years 8 months 12 days
Myst Merger Agreement [Member] \| Restricted Stock [Member]
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Award requisite service period	4 years
Share-based payment arrangement, non-vested award, cost not yet recognized, period for recognition				1 year 6 months
Share-based compensation arrangement by share-based payment award, equity instruments other than options, nonvested, number		181,480		181,480
Share-based payment arrangement, non-vested award, excluding option, cost not yet recognized, amount		$ 1,400		$ 1,400
Myst Merger Agreement [Member] \| Timothy Langer [Member]
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Business acquisition, equity interest issued or issuable, number of shares	725,920
Myst Merger Agreement [Member] \| Timothy Langer [Member] \| Restricted Stock [Member]
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Business acquisition, equity interest issued or issuable, number of shares	362,960
2018 Plan [Member]
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Award requisite service period				10 years
Award vesting period				4 years
Share-based compensation arrangement by share-based payment award, award vesting rights, percentage				25.00%
Number of shares authorized for issuance under share-based payment arrangement		35,000,000		35,000,000
Share-based compensation arrangement by share-based payment award, number of shares available for grant		159,243		159,243

Equity Based Compensation - Schedule of Stock Option Plan Activity (Detail) - 2018 Plan [Member] - USD ($) $ / shares in Units, $ in Thousands			6 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Jun. 30, 2023	Jun. 30, 2022
Schedule Of Share Based Compensation Stock Options Activity [Line Items]
Number of Shares Underlying Outstanding Options, Beginning balance			2,529,982	1,759,275
Options granted			189,365	874,879
Options exercised			(21,784)	(60,574)
Options canceled/forfeited			(92,924)	(22,679)
Number of Shares Underlying Outstanding Options, Ending balance	2,529,982	1,759,275	2,604,639	2,550,901
Exercisable			1,622,615	1,126,388
Vested and expected to vest			2,604,639	2,550,901
Weighted- Average Exercise Price Outstanding			$ 8.86	$ 7.26
Options granted			16.45	11.02
Options exercised			3.91	2.47
Options canceled/forfeited			10.46	8.14
Weighted- Average Exercise Price Outstanding	$ 8.86	$ 7.26	9.42	8.62
Exercisable			7.82	6.07
Vested and expected to vest			$ 9.42	$ 8.62
Weighted- Average Remaining Contractual Term (Years) Outstanding	6 years 9 months 18 days	7 years 2 months 12 days	6 years 9 months 18 days	7 years 6 months
Exercisable			5 years 8 months 12 days	5 years 8 months 12 days
Vested and expected to vest			6 years 9 months 18 days	7 years 6 months
Aggregate Intrinsic Value Outstanding , Beginning balance			$ 5,886	$ 6,912
Aggregate Intrinsic Value Outstanding , Ending balance	$ 5,886	$ 6,912	18,605	6,464
Exercisable			14,100	5,718
Vested and expected to vest			$ 18,605	$ 6,464

Leases - Schedule of Present Value of Operating Lease Payments (Detail)	Jun. 30, 2023
Schedule of Present Value of Operating Lease Payments [Abstract]
Weighted-average remaining lease term in years	1 year 10 months 24 days
Weighted-average discount rate	5.69%

Condensed Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders' Deficit - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Deficit [Member]	Series A redeemable convertible preferred stock [Member]	Series A redeemable convertible preferred stock [Member] Preferred Stock [Member]	Series B-1 Redeemable Convertible Preferred Stock [Member]	Series B-1 Redeemable Convertible Preferred Stock [Member] Preferred Stock [Member]	Series B-2 Redeemable Convertible Preferred Stock [Member]	Series B-2 Redeemable Convertible Preferred Stock [Member] Preferred Stock [Member]	Series C Redeemable Convertible Preferred Stock [Member]	Series C Redeemable Convertible Preferred Stock [Member] Preferred Stock [Member]	Series D redeemable convertible preferred stock [Member]	Series D redeemable convertible preferred stock [Member] Preferred Stock [Member]
Beginning balance (in shares) at Dec. 31, 2021							11,250,000		16,285,156		25,065,538		17,905,288		29,285,356
Beginning balance at Dec. 31, 2021							$ 8,582		$ 12,611		$ 28,860		$ 42,048		$ 79,653
Beginning balance (in shares) at Dec. 31, 2021		2,550,478
Beginning balance at Dec. 31, 2021	$ (81,851)	$ 3	$ 9,115	$ (245)	$ (90,724)
Accretion of redeemable convertible preferred stock issuance costs							$ 21						$ 17		$ 19
Accretion of redeemable convertible preferred stock issuance costs	(57)		(57)
Exercise of stock options (in shares)		1,064
Exercise of stock options	10		10
Stock-based compensation expense	962		962
Unrealized loss on available-for-sale debt securities	(94)			(94)
Net income (loss)	(12,616)				(12,616)
Ending balance (in shares) at Mar. 31, 2022							11,250,000		16,285,156		25,065,538		17,905,288		29,285,356
Ending balance at Mar. 31, 2022							$ 8,603		$ 12,611		$ 28,860		$ 42,065		$ 79,672
Ending balance (in shares) at Mar. 31, 2022		2,551,542
Ending balance at Mar. 31, 2022	(93,646)	$ 3	10,030	(339)	(103,340)
Beginning balance (in shares) at Dec. 31, 2021							11,250,000		16,285,156		25,065,538		17,905,288		29,285,356
Beginning balance at Dec. 31, 2021							$ 8,582		$ 12,611		$ 28,860		$ 42,048		$ 79,653
Beginning balance (in shares) at Dec. 31, 2021		2,550,478
Beginning balance at Dec. 31, 2021	(81,851)	$ 3	9,115	(245)	(90,724)
Unrealized loss on available-for-sale debt securities	(175)
Net income (loss)	(1,016)
Ending balance (in shares) at Jun. 30, 2022							11,250,000		16,285,156		25,065,538		17,905,288		29,285,356
Ending balance at Jun. 30, 2022							$ 8,623		$ 12,611		$ 28,860		$ 42,082		$ 79,692
Ending balance (in shares) at Jun. 30, 2022		2,702,770
Ending balance at Jun. 30, 2022	(74,972)	$ 3	17,185	(420)	(91,740)
Beginning balance (in shares) at Mar. 31, 2022							11,250,000		16,285,156		25,065,538		17,905,288		29,285,356
Beginning balance at Mar. 31, 2022							$ 8,603		$ 12,611		$ 28,860		$ 42,065		$ 79,672
Beginning balance (in shares) at Mar. 31, 2022		2,551,542
Beginning balance at Mar. 31, 2022	(93,646)	$ 3	10,030	(339)	(103,340)
Accretion of redeemable convertible preferred stock issuance costs							$ 20						$ 17		$ 20
Accretion of redeemable convertible preferred stock issuance costs	(57)		(57)
Issuance of common stock upon Myst milestone achievement	5,000		5,000
Moffitt performance based common stock award (in shares)		91,721
Moffitt performance based common stock award	1,026		1,026
Exercise of stock options (in shares)		59,507
Exercise of stock options	140		140
Stock-based compensation expense	1,046		1,046
Unrealized loss on available-for-sale debt securities	(81)			(81)
Net income (loss)	11,600				11,600
Ending balance (in shares) at Jun. 30, 2022							11,250,000		16,285,156		25,065,538		17,905,288		29,285,356
Ending balance at Jun. 30, 2022							$ 8,623		$ 12,611		$ 28,860		$ 42,082		$ 79,692
Ending balance (in shares) at Jun. 30, 2022		2,702,770
Ending balance at Jun. 30, 2022	$ (74,972)	$ 3	17,185	(420)	(91,740)
Beginning balance (in shares) at Dec. 31, 2022						11,250,000	11,250,000	16,285,156	16,285,156	25,065,538	25,065,538	17,905,288	17,905,288	29,285,356	29,285,356
Beginning balance at Dec. 31, 2022							$ 8,643		$ 12,611		$ 28,860		$ 42,100		$ 79,730
Beginning balance (in shares) at Dec. 31, 2022	2,915,757	2,915,757
Beginning balance at Dec. 31, 2022	$ (101,467)	$ 3	20,501	(413)	(121,558)
Accretion of redeemable convertible preferred stock issuance costs															$ 20
Accretion of redeemable convertible preferred stock issuance costs	(20)		(20)
Moffitt performance based common stock award (in shares)		91,721
Moffitt performance based common stock award	0
Exercise of stock options (in shares)		20,658
Exercise of stock options	83		83
Stock-based compensation expense	992		992
Unrealized loss on available-for-sale debt securities	121			121
Net income (loss)	68				68
Ending balance (in shares) at Mar. 31, 2023							11,250,000		16,285,156		25,065,538		17,905,288		29,285,356
Ending balance at Mar. 31, 2023							$ 8,643		$ 12,611		$ 28,860		$ 42,100		$ 79,750
Ending balance (in shares) at Mar. 31, 2023		3,028,136
Ending balance at Mar. 31, 2023	$ (100,223)	$ 3	21,556	(292)	(121,490)
Beginning balance (in shares) at Dec. 31, 2022						11,250,000	11,250,000	16,285,156	16,285,156	25,065,538	25,065,538	17,905,288	17,905,288	29,285,356	29,285,356
Beginning balance at Dec. 31, 2022							$ 8,643		$ 12,611		$ 28,860		$ 42,100		$ 79,730
Beginning balance (in shares) at Dec. 31, 2022	2,915,757	2,915,757
Beginning balance at Dec. 31, 2022	$ (101,467)	$ 3	20,501	(413)	(121,558)
Unrealized loss on available-for-sale debt securities	180
Net income (loss)	$ (21,431)
Ending balance (in shares) at Jun. 30, 2023						11,250,000	11,250,000	16,285,156	16,285,156	25,065,538	25,065,538	17,905,288	17,905,288	29,285,356	29,285,356
Ending balance at Jun. 30, 2023							$ 8,643		$ 12,611		$ 28,860		$ 42,100		$ 79,769
Ending balance (in shares) at Jun. 30, 2023	3,029,258	3,029,258
Ending balance at Jun. 30, 2023	$ (120,605)	$ 3	22,614	(233)	(142,989)
Beginning balance (in shares) at Mar. 31, 2023							11,250,000		16,285,156		25,065,538		17,905,288		29,285,356
Beginning balance at Mar. 31, 2023							$ 8,643		$ 12,611		$ 28,860		$ 42,100		$ 79,750
Beginning balance (in shares) at Mar. 31, 2023		3,028,136
Beginning balance at Mar. 31, 2023	(100,223)	$ 3	21,556	(292)	(121,490)
Accretion of redeemable convertible preferred stock issuance costs															$ 19
Accretion of redeemable convertible preferred stock issuance costs	(19)		(19)
Exercise of stock options (in shares)		1,122
Exercise of stock options	3		3
Stock-based compensation expense	1,074		1,074
Unrealized loss on available-for-sale debt securities	59			59
Net income (loss)	$ (21,499)				(21,499)
Ending balance (in shares) at Jun. 30, 2023						11,250,000	11,250,000	16,285,156	16,285,156	25,065,538	25,065,538	17,905,288	17,905,288	29,285,356	29,285,356
Ending balance at Jun. 30, 2023							$ 8,643		$ 12,611		$ 28,860		$ 42,100		$ 79,769
Ending balance (in shares) at Jun. 30, 2023	3,029,258	3,029,258
Ending balance at Jun. 30, 2023	$ (120,605)	$ 3	$ 22,614	$ (233)	$ (142,989)

Fair Value of Financial Assets and Liabilities - Schedule of financial assets and liabilities measured on recurring basis at fair value (Detail) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Financial assets:
Total financial assets	$ 44,362	$ 56,950
Contingent consideration [Member]
Financial liabilities:
Total financial liabilities	4,683	5,994
Fair value recurring basis [Member]
Financial assets:
Money market funds	16,540	9,238
Restricted cash	116	382
U.S. government and agency securities	27,706	47,330
Total financial assets	44,362	56,950
Financial liabilities:
Total financial liabilities	4,683	5,994
Fair value recurring basis [Member] \| Contingent consideration [Member]
Financial liabilities:
Contingent consideration	4,683	5,994
Fair value recurring basis [Member] \| Level 1 [Member]
Financial assets:
Money market funds	16,540	9,238
Restricted cash	116	382
U.S. government and agency securities	18,746	30,649
Total financial assets	35,402	40,269
Fair value recurring basis [Member] \| Level 2 [Member]
Financial assets:
U.S. government and agency securities	8,960	16,681
Total financial assets	8,960	16,681
Fair value recurring basis [Member] \| Level 3 [Member]
Financial liabilities:
Total financial liabilities	4,683	5,994
Fair value recurring basis [Member] \| Level 3 [Member] \| Contingent consideration [Member]
Financial liabilities:
Contingent consideration	$ 4,683	$ 5,994

Net Earnings (Loss) per Share (Tables)

6 Months Ended

Jun. 30, 2023

Earnings Per Share [Abstract]

Schedule of computation of basic and diluted net loss per share

The following table sets forth the computation of the basic and diluted net loss per share (

in thousands, except share and per share data


	Three Months Ended June 30,						Six Months Ended June 30,
	2023			2022			2023			2022
Net income (loss)	$	(21,499	)	$	11,600		$	(21,431	)	$	(1,016	)
Less: accretion of Preferred Stock to redemption value		(19	)		(57	)		(39	)		(114	)
Less: undistributed earnings allocable to participating securities		—			(10,355	)		—			—

Net income (loss) attributable to common stockholders, basic and diluted	$	(21,518	)	$	1,188		$	(21,470	)	$	(1,130	)

Weighted-average number of basic shares used in computing net earnings (loss) per share		2,847,675			2,355,553			2,817,008			2,317,631
Effect of dilutive securities
Stock options		—			442,002			—			—
Restricted stock		—			29,683			—			—
Redeemable converted preferred stock		—			—			—			—

Weighted-average number of diluted shares used in computing net earnings (loss) per share		2,847,675			2,827,238			2,817,008			2,317,631

Net earnings (loss) per share
Basic	$	(7.56	)	$	0.50		$	(7.62	)	$	(0.49	)

Diluted	$	(7.56	)	$	0.42		$	(7.62	)	$	(0.49	)

Schedule of dilutive securities excluded from computation of diluted net loss per share

as-converted

basis).


Restricted stock			181,480
Options to purchase common stock			2,604,639
Redeemable convertible preferred stock			12,493,879

Total			15,279,998

Summary of Significant Accounting Policies (Policies)	6 Months Ended
Summary of Significant Accounting Policies (Policies)	Jun. 30, 2023
Accounting Policies [Abstract]
Basis of Presentation of Unaudited Condensed Consolidated Financial Information	Basis of Presentation of Unaudited Condensed Consolidated Financial Information The accompanying unaudited condensed consolidated financial statements of the Company have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) for interim financial information and pursuant to the rules and regulations of the SEC. Accordingly, they do not include all the information and footnotes required by GAAP for complete financial statements. However, such interim financial statements reflects all adjustments (consisting solely of normal recurring adjustments), which are, in the opinion of management, necessary for the fair presentation of the Company’s financial position and results of operations. Results shown for interim periods are not necessarily indicative of the results that may be expected for the year ended December 31, 2023 or for any other period. The condensed consolidated balance sheet as of December 31, 2022 was derived from the audited consolidated financial statements. These unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements, included in the Company’s final prospectus filed with the SEC pursuant to Rule 424(b)(4) on July 2 4 , 2023. Certain prior period amounts reported in the Company’s unaudited condensed consolidated financial statements and accompanying notes have been reclassified to conform to the current period presentation. Any reference in these notes to applicable guidance is meant to refer to the authoritative accounting principles generally accepted in the United States as found in the Accounting Standard Codification (“ASC”) and Accounting Standards Update (“ASU”) of the Financial Accounting Standards Board (“FASB”).
Principles of Consolidation	Principles of Consolidation The accompanying unaudited condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation.
Significant Accounting Policies	Significant Accounting Policies The significant accounting policies used in preparation of these unaudited condensed consolidated financial statements are consistent with those discussed in Note 2 to the audited consolidated financial statements included in the Company’s final prospectus filed with the SEC pursuant to Rule 424(b)(4) on July 2 4 , 2023.
Use of Estimates	Use of Estimates The preparation of these unaudited condensed consolidated financial statements in accordance with GAAP requires management to make estimates and assumptions that affect the amounts reported in the unaudited condensed consolidated financial statements and accompanying notes. On an ongoing basis, management evaluates its estimates, including those related to accrued expenses, contingent liabilities, revenue recognition, the valuation of equity-based compensation, common stock, restricted common stock, and income taxes. The Company bases its estimates on various assumptions that the Company believes to be reasonable under the circumstances. Actual results could differ from those estimates.
Restricted Cash and Investments	Restricted Cash and Investments Restricted cash consists of certificate of deposit accounts that are pledged as collateral for the Company’s San Diego facility lease as of June 30, 2023 and the San Diego and New York facility leases as of December 31, 2022. Restricted cash was approximately $0.1 million and $0.4 million as of June 30, 2023 and December 31, 2022, respectively. The Company invests its excess cash in investment grade, short-term, fixed income securities and recognizes purchased securities on the settlement date. All investments have been classified as “available-for-sale” in the unaudited condensed consolidated balance sheets, and are carried at estimated fair value based upon quoted market prices or pricing models for similar securities. Management determines the appropriate classification of its investments at the time of purchase and re-evaluates such designation as of each balance sheet date. The Company assesses its available-for-sale securities under the available-for-sale security impairment model in ASC 326 as of each reporting date in order to determine if a portion of any decline in fair value below carrying value is the result of a credit loss. The Company records credit losses in the unaudited condensed consolidated statements of operations and comprehensive income (loss) as credit loss expense, which is limited to the difference between the fair value and the amortized cost of the security. To date, the Company has not recorded any credit losses on its available-for-sale securities. Declines in fair value below carrying value attributable to non-credit related factors are recorded as accumulated other comprehensive loss, which is a separate component of stockholders’ deficit. Realized gains and losses are reported in other income (expense), net. Interest on short-term investments is included in other income (expense), net. The Company’s investments are classified as current assets, even though the stated maturity date may be one year or more beyond the current balance sheet date, which reflects management’s intention to use the proceeds from sales of these securities to fund its operations, as necessary.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash and cash equivalents, investments and restricted cash. The Company’s investment policy restricts cash investments to high credit quality, investment grade investments. The Company’s investment policy provides guidelines and limits regarding investment type, concentration, credit quality, and maturity aimed at maintaining sufficient liquidity to satisfy operating and working capital requirements along with strategic initiatives, preserving capital, and minimizing risk of capital loss while generating returns on its investments. The Company is exposed to credit risk in the event of default by the issuer or the institutions holding the cash and cash equivalents to the extent of the amounts recorded on the balance sheets. The Company records accounts receivable amounts invoiced to a collaborator, for which the Company has an unconditional right to consideration. For amounts to which the Company has an unconditional right to consideration but has not yet invoiced the collaborator, the Company records unbilled accounts receivable. The Company estimates an allowance for credit losses based on the creditworthiness of its collaborator, current economic conditions and future economic conditions, as may be applicable. If a receivable is deemed to be uncollectible, the balance is charged against the allowance. As of June 30, 2023 and December 31, 2022, the Company had an accounts receivable balance of $ 0.3 million and $8.7 million, respectively of which Takeda accounted for 100%, and no allowance was recorded. Accounts receivable and unbilled accounts receivable are presented in accounts receivable, net on the unaudited condensed consolidated balance sheets. During the three months and six months ended June 30, 2023 and 2022, the Company did not recognize any charges for write-offs of accounts receivable. The Company has no off-balance sheet risk, such as foreign exchange contracts, option contracts or other foreign-hedging arrangements.
Fair Value Measurements	Fair Value Measurements The Company applies fair value accounting for all financial assets and liabilities and non-financial assets and liabilities that are recognized or disclosed at fair value in the unaudited condensed consolidated financial statements on a recurring basis. Fair value is defined as the exchange price that would be received for an asset or an exit price that would be paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The fair value hierarchy requires that an entity maximize the use of observable inputs when estimating fair value. The fair value hierarchy includes the following three-level classification which is based on the market observability of the inputs used for estimating the fair value of the assets or liabilities being measured: Level 1 – Quoted market prices in active markets for identical assets or liabilities. Level 2 – Observable inputs other than quoted prices in active markets for identical assets and liabilities, quoted prices for identical or similar assets or liabilities in inactive markets, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3 – Inputs that are generally unobservable and typically reflect management’s estimate of assumptions that a market participant would use in pricing the asset or liability. Fair value accounting is applied for all financial assets and liabilities and non-financial assets and liabilities that are recognized at fair value in the unaudited condensed consolidated financial statements on a recurring basis (at least annually). To the extent the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair values requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized as Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement.
Stock-Based Compensation	Stock-Based Compensation The Company measures the cost of employee, nonemployee and director services received in exchange for an award of equity instruments based on the fair value of the award on the date of grant and recognizes the related expense over the period during which the employee, nonemployee or director is required to provide service in exchange for the award on a straight-line basis. The Company estimates the fair value of options granted using the Black-Scholes option pricing model (“Black-Scholes”) and the fair value of common stock to determine the fair value of restricted stock. The determination of fair value for stock-based awards on the date of grant using an option-pricing model requires management to make certain assumptions regarding a number of variables. Upon adoption of ASU 2016-09, the Company can make an accounting policy election to either estimate the number of share-based awards that are expected to vest, or account for forfeitures when they occur. The Company elected to account for forfeitures when they occur. As such, the Company recognizes stock-based compensation expense, over the requisite service period, based on the vesting provisions of the individual grants. The Black-Scholes option pricing model requires inputs based on certain subjective assumptions, including (a) the expected stock price volatility, (b) the expected term of the award, (c) the risk-free interest rate and (d) expected dividend yields. Due to the lack of a public market for the Company’s common stock until July 21, 2023, and lack of company- specific historical and implied volatility data, the Company has based its computation of expected volatility on the average historical volatility of a representative group of public companies with similar characteristics to the Company, including stage of product development and life science industry focus. The historical volatility is calculated based on a period of time commensurate with the expected term. The Company uses the simplified method as prescribed by the U.S. Securities and Exchange Commission Staff Accounting Bulletin No. 107, Share-Based Payment, to calculate the expected term for options granted to employees as it does not have sufficient historical exercise data to provide a reasonable basis upon which to estimate the expected term. The expected term is applied to the stock option grant group as a whole, as the Company does not expect substantially different exercise or post-vesting termination behavior among its employee population. The risk-free interest rate is based on a treasury instrument whose term is consistent with the expected term of the stock options. The expected dividend yield is assumed to be zero as the Company has never paid dividends and has no current plans to pay any dividends on its common stock.
Determination of Fair Value of Common Stock	Determination of Fair Value of Common Stock There are significant judgments and estimates inherent in the determination of the fair value of the Company’s common stock. These estimates and assumptions include a number of objective and subjective factors, including, among other things, external market conditions, the prices at which the Company sold shares of its convertible preferred stock, the superior rights and preferences of securities senior to its common stock at the time of, and the likelihood of, achieving a liquidity event, such as an initial public offering or sale of the Company. The approach to estimating the fair market value of common stock is consistent with the methods outlined in the American Institute of Certified Public Accountants’ Accounting and Valuation Guide, Valuation of Privately-Held Company Equity Securities Issued as Compensation (the “Practice Aid”). In valuing the Company’s common stock, the equity value of the business was determined using the backsolve method, a form of the subject company transaction method, wherein the equity value for a privately held company is derived from a recent transaction in the company’s own securities. The value is then allocated using the hybrid method allocation methodology. For grants made prior to September 30, 2018, in accordance with the Practice Aid, the Company determined the option pricing method (“OPM”), was the most appropriate method for determining the fair value of the Company’s common stock based on its stage of development and other relevant factors. For grants made subsequent to September 30, 2018, the Company used a hybrid method, which is a hybrid between the OPM and the probability-weighted expected return method (“PWERM”). The hybrid method is a combination of the PWERM and OPM. The OPM allocates the overall Company value to the various share classes based on differences in liquidation preferences, participation rights, dividend policy and conversion rights, using a series of call options. The call right is valued using a Black-Scholes option pricing model. The PWERM employs additional information not used in the OPM, including various market approach calculations depending upon the likelihood of various discrete future liquidity scenarios, such as an initial public offering or sale of the Company, as well as the probability of remaining a private company. In a hybrid method, various exit scenarios are analyzed. A discount for lack of marketability of the Company’s common stock is then applied to arrive at an indication of value for the common stock.
Redeemable Convertible Preferred Stock	Redeemable Convertible Preferred Stock The Company records all proceeds from redeemable convertible preferred stock (“Preferred Stock”) net of issuance costs. The Company classifies Preferred Stock outside of stockholders’ deficit due to certain events that are outside of the Company’s control, including sale or transfer of control of the Company, or redemption upon the election of the required majority of the Preferred Stockholders any time after June 29, 2026, as holders of the Preferred Stock could cause redemption of the shares in these situations. The Company adjusts the carrying values of the Preferred Stock to the ultimate redemption values over the period from issuance to the earliest redemption date.
Deferred Offering Costs	Deferred Offering Costs The Company has deferred offering costs consisting of legal, accounting and other fees and costs directly attributable to the Company’s IPO and are included with other assets, noncurrent in the balance sheets. The deferred offering costs will be offset against the proceeds received upon the completion of the IPO. As of June 30, 2023 and December 31, 2022, the Company recorded $ 4.4 million and $1.9 million of deferred offering costs, respectively.
Contingent Consideration	Contingent Consideration Consideration paid related to the Myst Merger Agreement (as defined below) may include potential future payments that are contingent upon the Company achieving certain milestones in the future. Contingent consideration liabilities are measured at their estimated fair value as of the date of the unaudited condensed consolidated balance sheets using a probability-based income approach based on the monetary value of the milestone payment discounted for the likelihood of achieving the milestone and a present value factor based on the timing of when the milestone is expected to be achieved. Contingent consideration liabilities expected to be settled within 12 months after the balance sheet date are presented in current liabilities, with the non-current portion recorded under other liabilities, non-current in the unaudited condensed consolidated balance sheets. Changes in the fair value of the contingent consideration are recorded as research and development expenses in the unaudited condensed consolidated statement of operations and comprehensive income (loss).
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326)—Measurement of Credit Losses on Financial Instruments, which has been subsequently amended by ASU No. 2018-19, ASU No. 2019-04, ASU No. 2019-05, ASU No. 2019-10, ASU No. 2019-11 and ASU No. 2021-03 (“ASU 2016-13”). The provisions of ASU 2016-13 modify the impairment model to utilize an expected loss methodology in place of the currently used incurred loss methodology and require a consideration of a broader range of reasonable and supportable information to inform credit loss estimates. ASU 2016-13 is effective for the Company on January 1, 2023. The adoption did not have a material impact on the unaudited condensed consolidated financial statements.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In August 2020, the FASB issued ASU No. 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging Contracts in Entity’s Own Equity (Subtopic 815-40) (“ASU 2020-06”), which reduces the number of accounting models for convertible debt instruments and convertible preferred stock as well as amends the derivatives scope exception for contracts in an entity’s own equity. ASU 2020-06 is effective for the Company on January 1, 2024, with early adoption permitted. The Company is currently evaluating the potential impact that this standard may have on its unaudited condensed consolidated financial statements and related disclosures.

Leases - Schedule of Information about Lease Costs (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Lease, Cost [Abstract]
Operating lease cost	$ 558	$ 545	$ 1,138	$ 871
Short-term lease costs		(7)	1	249
Variable leases costs		13	5	14
Sublease income	(128)		(238)
Total lease cost	$ 430	$ 551	$ 906	$ 1,134

Net Earnings (Loss) per Share - Schedule of Computation of Basic And Diluted Net Loss Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income (loss)	$ (21,499)	$ 68	$ 11,600	$ (12,616)	$ (21,431)	$ (1,016)
Less: undistributed earnings allocable to participating securities			(10,355)
Net income (loss) attributable to common stockholders, basic	(21,518)		1,188		(21,470)	(1,130)
Net income (loss) attributable to common stockholders, Diluted	$ (21,518)		$ 1,188		$ (21,470)	$ (1,130)
Weighted-average number of basic shares used in computing net earnings (loss) per share	2,847,675		2,355,553		2,817,008	2,317,631
Effect of dilutive securities
Stock options			$ 442,002
Restricted stock			$ 29,683
Weighted-average number of diluted shares used in computing net earnings (loss) per share	2,847,675		2,827,238		2,817,008	2,317,631
Net earnings (loss) per share
Basic	$ (7.56)		$ 0.5		$ (7.62)	$ (0.49)
Diluted	$ (7.56)		$ 0.42		$ (7.62)	$ (0.49)
Redeemable Convertible Preferred Stock [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Less: accretion of preferred stock to redemption value	$ (19)		$ (57)		$ (39)	$ (114)
Effect of dilutive securities
Redeemable converted preferred stock			$ 0

Equity Based Compensation (Tables)

6 Months Ended

Jun. 30, 2023

Share-Based Payment Arrangement [Abstract]

Schedule of stock option plan activity

A summary of the stock option activity under the 2018 Plan is as follows:


	Number of Shares Underlying Outstanding Options			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value (in thousands)
Outstanding — December 31, 2021		1,759,275		$	7.26		7.2	$	6,912

Options granted		874,879		$	11.02
Options exercised		(60,574	)	$	2.47
Options canceled/forfeited		(22,679	)	$	8.14

Outstanding — June 30, 2022		2,550,901		$	8.62		7.5	$	6,464

Exercisable — June 30, 2022		1,126,388		$	6.07		5.7	$	5,718

Vested and expected to vest — June 30, 2022		2,550,901		$	8.62		7.5		6,464

Outstanding — December 31, 2022		2,529,982		$	8.86		6.8	$	5,886

Options granted		189,365		$	16.45
Options exercised		(21,784	)	$	3.91
Options canceled/forfeited		(92,924	)	$	10.46

Outstanding — June 30, 2023		2,604,639		$	9.42		6.8	$	18,605

Exercisable — June 30, 2023		1,622,615		$	7.82		5.7	$	14,100

Vested and expected to vest — June 30, 2023		2,604,639		$	9.42		6.8	$	18,605

Schedule of fair value assumption of stock option activity

The fair value of each stock option granted to employees and directors was estimated on the date of grant using the Black-Scholes option-pricing model, with the following range of assumptions:


	Six Months Ended June 30,
	2023	2022
Risk-free interest rate	3.89% - 4.48%	1.48% - 3.00%
Expected term (in years)	6.09 - 6.20	5.69 - 5.92
Dividend yield	0%	0%
Volatility	85.8% - 86.2%	86.8% - 87.2%
Exercise price of stock options grante d	$11.18 - $16.53	10.94 - 11.18

Schedule of stock based compensation for stock awards

Stock-based compensation expense for all stock awards included in the Company’s statements of operations are as follows (

in thousands


	Three Months Ended June 30,				Six Months Ended June 30,
	2023		2022		2023		2022
Research and development	$	507	$	542	$	1,009	$	1,063
General and administrative		567	$	505		1,057		946

Total stock-based compensation	$	1,074	$	1,047	$	2,066	$	2,009

Nature of the Business and Basis of Presentation	6 Months Ended
Nature of the Business and Basis of Presentation	Jun. 30, 2023
Business Description And Basis Of Presentation [Abstract]
Nature of the Business and Basis of Presentation	1. Nature of the Business and Basis of Presentation Organization Turnstone Biologics Corp. (the “Company” or “Turnstone”) is a clinical stage biotechnology company focused on developing new medicines to treat and cure patients with solid tumors. Turnstone is pioneering a differentiated approach to tumor infiltrating lymphocytes (“TILs”), a clinically validated technology for treating solid tumors. The Company is developing next generation TIL therapies by selecting the most potent and tumor reactive T cells (“Selected TILs”). The Company has initiated two Phase 1 clinical trials for its lead Selected TIL product candidate, TIDAL-01, for the treatment of breast cancer, colorectal cancer, uveal melanoma and other non-cutaneous and cutaneous melanomas. Turnstone Biologics Inc. (“Turnstone Canada”) was incorporated as a Canadian corporation on March 27, 2014. On December 13, 2018, Turnstone Biologics Corp. was incorporated under the laws of the State of Delaware. On December 14, 2018, the Company completed a reorganization from Canada to the United States (the “Reorganization”). In connection with the Reorganization, all of the shareholders of Turnstone Canada exchanged their shares in Turnstone Canada for shares of the newly incorporated Delaware entity, as a result of which Turnstone Canada became the newly incorporated Delaware entity’s wholly owned subsidiary. The corporate reorganization was a common control reorganization applied on a retrospective basis. The Company’s headquarters are located in San Diego, California. Reverse Stock Split On July 14, 2023, the Company effected a 1-for-7.9872 reverse stock split (“Reverse Split”) of its issued and outstanding shares of common stock and redeemable convertible preferred stock. All share and per share amounts included in the accompanying unaudited condensed consolidated financial statements and related notes have been retroactively adjusted, where applicable, to reflect the Reverse Split, including reclassifying an amount equal to the reduction in par value of common stock to additional paid-in capital. Shares of common stock, underlying outstanding stock options, and restricted stock were proportionately reduced and the respective exercise prices, if applicable, were proportionately increased in accordance with the terms of the appropriate securities agreements. Stockholders entitled to fractional shares as a result of the Reverse Split received a cash payment in lieu of receiving fractional shares. Initial Public Offering On July 25, 2023, the Company completed its IPO pursuant to which it issued and sold an aggregate of 6,666,667 shares of common stock at a price to the public of $12.00 per share , Aggregate net proceeds to the Company were $70.1 million after deducting underwriting discounts and commissions of $5.6 million and other offering expenses of $4.3 million. On August 15, 2023, the underwriters exercised their option to purchase an additional 651,608 shares of common stock at $12.00 per share. Aggregate net proceeds to the Company were $7.3 million after deducting underwriting discounts and commissions of $0.5 million. Upon the closing of the IPO, all outstanding shares of redeemable convertible preferred stock automatically converted into shares of common stock. Subsequent to the closing of the IPO, there were no shares of redeemable convertible preferred stock outstanding. In connection with the closing of the IPO, the Company filed its Amended and Restated Certificate of Incorporation which provides that the authorized capital stock of the Company is 500,000,000 shares consisting of 490,000,000 shares of common stock and 10,000,000 shares of undesignated preferred stock, both with a par value of $0.001 per share. Sources of Liquidity Since its inception, the Company has devoted substantially all of its efforts and financial resources to organizing and staffing the Company, business planning, raising capital, discovering product candidates and securing related intellectual property rights, and conducting research and development activities for its Selected TIL programs and product candidates. The Company does not have any products approved for sale, has not generated any revenue from product sales and has incurred overall net losses since commencement of the Company’s operations, including a net loss of $21.4 million and $1.0 million for the six months ended June 30, 2023 and 2022, respectively. The Company has financed its operations through the issuance and sale of shares of the Company’s redeemable convertible preferred stock, from collaboration revenue received pursuant to certain collaboration agreements, and most recently, with proceeds from the IPO completed on July 25, 2023 and the exercise of the underwriters option to purchase additional shares on August 15, 2023. As of June 30, 2023, the Company had an accumulated deficit of $ 143.0 million. The Company expects to continue to generate significant operating losses for the foreseeable future. The Company has evaluated and concluded there are no conditions or events, considered in the aggregate, that raise substantial doubt about its ability to continue as a going concern for a period of one year following the date these unaudited condensed consolidated financial statements are issued and believes its existing cash and cash equivalents and short-term investments as of June 30, 2023 of $49.2 million, together with the net proceeds of $77.4 million received from its IPO and exercise of the underwriters option to purchase additional shares, will be sufficient to fund its operating expenses and capital expenditure requirements for at least 12 months from the date these unaudited condensed consolidated financial statements are filed with the Securities and Exchange Commission (“SEC”). The Company intends to fund future operations and future capital funding needs through equity and/or debt financings, as well as possible asset sales, licensing transactions, and collaborations or strategic partnerships with other companies. The sale of equity or convertible debt could result in additional dilution to stockholders. The incurrence of indebtedness would result in debt service obligations and could result in operating and financial covenants that would restrict the Company’s operations. The Company can provide no assurance that sufficient financing will be available on acceptable terms, if at all. If the Company is not able to secure adequate additional funding it may be forced to make reductions in spending, extend payment terms with suppliers, liquidate assets where possible, and/or suspend or curtail planned programs. Any of these actions could materially harm the Company’s business. Risks and Uncertainties The Company is subject to risks and uncertainties common to early-stage companies in the biotechnology industry, including, but not limited to, development by competitors of new technological innovations, dependence on key personnel, protection of proprietary technology, compliance with government regulations and the ability to secure additional capital to fund operations. Product candidates currently under development will require significant additional research and development efforts, including non-clinical and clinical testing and regulatory approval, prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel and infrastructure and extensive compliance and reporting capabilities. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will realize significant revenue from product sales.

Fair Value of Financial Assets and Liabilities - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Fair Value Disclosures [Line Items]
Unpaid liability on milestone acheivement					$ 2,200
Short-term investments [Member]
Fair Value Disclosures [Line Items]
Asset impairment charges	$ 0	$ 0	$ 0	$ 0
Myst [Member]
Fair Value Disclosures [Line Items]
Contingent consideration liability	$ 4,700		$ 4,700		$ 6,000

Fair Value of Financial Assets and Liabilities (Tables)

6 Months Ended

Jun. 30, 2023

Fair Value Disclosures [Abstract]

Schedule of Financial Assets and Liabilities Measured on Recurring Basis at Fair Value

The following tables represents a summary of the financial assets and liabilities that are measured on a recurring basis at fair value

(in thousands)


	June 30, 2023
	Level 1		Level 2		Level 3		Fair Value
Financial assets:
Money market funds	$	16,540	$	—	$	—	$	16,540
Restricted cash (1)		116		—		—		116
U.S. government and agency securities (2)		18,746		8,960		—		27,706

Total financial assets	$	35,402	$	8,960	$	—	$	44,362

Financial liabilities:
Contingent consideration (3)	$	—	$	—	$	4,683	$	4,683

Total financial liabilities	$	—	$	—	$	4,683	$	4,683


	December 31, 2022
	Level 1		Level 2		Level 3		Fair Value
Financial assets:
Money market funds	$	9,238	$	—	$	—	$	9,238
Restricted cash (1)		382		—		—		382
U.S. government and agency securities (2)		30,649		16,681		—		47,330

Total financial assets	$	40,269	$	16,681	$	—	$	56,950

Financial liabilities:
Contingent consideration (3)	$	—	$	—	$	5,994	$	5,994

Total financial liabilities	$	—	$	—	$	5,994	$	5,994

(1)	Restricted cash serves as deposits for the Company’s San Diego office lease as of June 30, 2023 and New York and San Diego office leases as of December 31, 2022.

(2)	Included in short-term investments on the unaudited condensed consolidated balance sheets and are classified as available-for sale debt securities.

(3)	Contingent consideration related to the Myst Merger Agreement.

Schedule of Unobservable Input of Contingent Consideration Valuation

The following significant unobservable inputs were used in the valuation of the contingent consideration payable to the sole common stockholder of Myst pursuant to the Myst Merger Agreement:

Contingent Consideration Liability

Fair Value as of

June 30, 2023

Valuation Technique

Unobservable Input

Range

(in thousands)

Milestone payments

4,683

Discounted cash flow

Likelihood of occurrence

20% - 75%

Discount rate

Expected term (in years)

0.25-2.50

Contingent Consideration Liability

Fair Value as of

December 31, 2022

Valuation Technique

Unobservable Input

Range

(in thousands)

Milestone payments

5,994

Discounted cash flow

Likelihood of occurrence

20% - 100%

Discount rate

22%

Expected term (in years)

0.25-2.75

Schedule of Company's Contingent Consideration Measured at Fair Value Level 3

The following table reflects the activity for the Company’s contingent consideration, measured at fair value using Level 3 inputs (

in thousands


Contingent consideration at December 31, 2022	$	5,994
Cash payment of Myst milestone		(2,187	)
Changes in the fair value of contingent consideration		876

Contingent consideration at June 30, 2023	$	4,683

Schedule of Company's Cash, Cash Equivalents and Available-for-Sale Securities

The following tables show the Company’s cash, cash equivalents and

available-for-sale

securities by significant investment category

(in thousands


	June 30, 2023
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Level 1: Money market funds	$	16,540	$	—	$	—		$	16,540
Restricted cash		116		—		—			116
U.S. government securities		18,743		5		(2	)		18,746
Level 2: U.S. agency securities		8,973		—		(13	)		8,960

Total financial assets	$	44,372	$	5	$	(15	)	$	44,362

Classified as:
Cash and cash equivalents								$	16,540
Restricted cash									116
Short-term investments									27,706

								$	44,362


	December 31, 2022
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Level 1: Money market funds	$	9,238	$	—	$	—		$	9,238
Restricted cash		382		—		—			382
U.S. government securities		30,761		—		(112	)		30,649
Level 2: U.S. agency securities		16,759		—		(78	)		16,681

Total financial assets	$	57,140	$	—	$	(190	)	$	56,950

Classified as:
Cash and cash equivalents								$	9,238
Restricted cash									382
Short-term investments									47,330

								$	56,950

Condensed Consolidated Statements of Operations and Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Collaboration revenue		$ 41,915	$ 19,306	$ 52,633
Operating expenses:
Research and development	$ 17,193	26,537	32,861	45,238
General and administrative	4,659	3,932	8,691	8,630
Total operating expenses	21,852	30,469	41,552	53,868
Income (loss) from operations	(21,852)	11,446	(22,246)	(1,235)
Other income (expense), net	347	180	727	265
Net income (loss) before income taxes	(21,505)	11,626	(21,519)	(970)
Benefit (provision) for income taxes	6	(26)	88	(46)
Net income (loss)	(21,499)	11,600	(21,431)	(1,016)
Other comprehensive income (loss):
Unrealized gain (loss) on available-for-sale debt securities	59	(81)	180	(175)
Total comprehensive income (loss)	(21,440)	11,519	(21,251)	(1,191)
Net income (loss)	(21,499)	11,600	(21,431)	(1,016)
Less: accretion of preferred stock to redemption value	(19)	(57)	(39)	(114)
Less: undistributed earnings allocable to participating securities		(10,355)
Net income (loss) attributable to common stockholders, basic	(21,518)	1,188	(21,470)	(1,130)
Net income (loss) attributable to common stockholders, diluted	$ (21,518)	$ 1,188	$ (21,470)	$ (1,130)
Weighted-average number of shares used in computing net earnings (loss) per share
Basic	2,847,675	2,355,553	2,817,008	2,317,631
Diluted	2,847,675	2,827,238	2,817,008	2,317,631
Net income (loss) per share attributable to common stockholders
Basic	$ (7.56)	$ 0.5	$ (7.62)	$ (0.49)
Diluted	$ (7.56)	$ 0.42	$ (7.62)	$ (0.49)

Accrued Expenses and Other Current Liabilities

6 Months Ended

Jun. 30, 2023

Accrued Liabilities and Other Liabilities [Abstract]

Accrued Expenses and Other Current Liabilities

5. Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consist of the following

(in thousands):


	June 30, 2023		December 31, 2022
Research and development expense	$	8,534	$	6,688
Professional and consulting expense		3,104		1,170
Compensation		2,496		2,366
Tax liability, current		83		252
Contingent consideration, current		2,250		3,791
Other current liabilities		—		20

Total accrued expenses and other current liabilities	$	16,467	$	14,287

Equity Based Compensation - Schedule of Stock Based Compensation for Stock Awards (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation	$ 1,074	$ 1,047	$ 2,066	$ 2,009
Research and development [Member]
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation	507	542	1,009	1,063
General and administrative [Member]
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation	$ 567	$ 505	$ 1,057	$ 946

Fair Value of Financial Assets and Liabilities

6 Months Ended

Jun. 30, 2023

Fair Value Disclosures [Abstract]

Fair Value of Financial Assets and Liabilities

3. Fair Value of Financial Assets and Liabilities

For a description of the fair value hierarchy and our fair value methodology, see Note 2 – Summary of Significant Accounting Policies for additional information. As of June 30, 2023 and December 31, 2022, the Company’s restricted cash which is maintained as collateral in connection with its New York and San Diego facility leases, (See Note 2 – Summary of Significant Accounting Policies for additional information) are valued using Level 1 inputs. The Company’s highly liquid money market funds included within cash equivalents, restricted cash and U.S. treasury securities are valued using Level 1 inputs. The Company classifies its federal agency securities as Level 2. There were no transfers in or out of Level 1 and Level 2 during the periods presented. U.S. treasury securities are bonds issued by the U.S. government and are fully backed by the U.S. government. Given the frequency at which U.S. treasury securities trade and the accessibility of observable, quoted prices for such assets in active markets, they are recognized as Level 1 assets. Federal agency securities are bonds and notes issued by government-sponsored enterprises, including Fannie Mae, Freddie Mac and the Federal Home Loan Bank. Since Federal agency securities typically do not trade as frequently as U.S. government agency securities and no exchange exists to price such investments, they are recognized as Level 2 assets.

The Company had $4.7 million and $6.0 million in contingent consideration liabilities as of June 30, 2023 and December 31, 2022, respectively, related to the Myst Merger Agreement. The contingent consideration balances are comprised of two separate potential milestone payments as of June 30, 2023 and two separate potential milestone payments as well as the remaining unpaid liability of $2.2 million from the milestone achievement as of December 31, 2022 with each measured at fair value (See Note 7—Asset Acquisition for additional information). The fair value of the contingent consideration is estimated based on the monetary value of the milestone discounted for the likelihood of achieving the milestone and a present value factor based on the timing of when the milestone is expected to be achieved. The value for the contingent consideration balance is based on significant inputs not observable in the market which represents a Level 3 measurement within the fair value hierarchy. There were no transfers in or out of Level 3 during the periods presented.

The following tables represents a summary of the financial assets and liabilities that are measured on a recurring basis at fair value

(in thousands)


	June 30, 2023
	Level 1		Level 2		Level 3		Fair Value
Financial assets:
Money market funds	$	16,540	$	—	$	—	$	16,540
Restricted cash (1)		116		—		—		116
U.S. government and agency securities (2)		18,746		8,960		—		27,706

Total financial assets	$	35,402	$	8,960	$	—	$	44,362

Financial liabilities:
Contingent consideration (3)	$	—	$	—	$	4,683	$	4,683

Total financial liabilities	$	—	$	—	$	4,683	$	4,683


	December 31, 2022
	Level 1		Level 2		Level 3		Fair Value
Financial assets:
Money market funds	$	9,238	$	—	$	—	$	9,238
Restricted cash (1)		382		—		—		382
U.S. government and agency securities (2)		30,649		16,681		—		47,330

Total financial assets	$	40,269	$	16,681	$	—	$	56,950

Financial liabilities:
Contingent consideration (3)	$	—	$	—	$	5,994	$	5,994

Total financial liabilities	$	—	$	—	$	5,994	$	5,994

(1)	Restricted cash serves as deposits for the Company’s San Diego office lease as of June 30, 2023 and New York and San Diego office leases as of December 31, 2022.

(2)	Included in short-term investments on the unaudited condensed consolidated balance sheets and are classified as available-for sale debt securities.

(3)	Contingent consideration related to the Myst Merger Agreement.

The following significant unobservable inputs were used in the valuation of the contingent consideration payable to the sole common stockholder of Myst pursuant to the Myst Merger Agreement:

Contingent Consideration Liability

Fair Value as of

June 30, 2023

Valuation Technique

Unobservable Input

Range

(in thousands)

Milestone payments

4,683

Discounted cash flow

Likelihood of occurrence

20% - 75%

Discount rate

Expected term (in years)

0.25-2.50

Contingent Consideration Liability

Fair Value as of

December 31, 2022

Valuation Technique

Unobservable Input

Range

(in thousands)

Milestone payments

5,994

Discounted cash flow

Likelihood of occurrence

20% - 100%

Discount rate

22%

Expected term (in years)

0.25-2.75

The following table reflects the activity for the Company’s contingent consideration, measured at fair value using Level 3 inputs (

in thousands


Contingent consideration at December 31, 2022	$	5,994
Cash payment of Myst milestone		(2,187	)
Changes in the fair value of contingent consideration		876

Contingent consideration at June 30, 2023	$	4,683

The following tables show the Company’s cash, cash equivalents and

available-for-sale

securities by significant investment category

(in thousands


	June 30, 2023
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Level 1: Money market funds	$	16,540	$	—	$	—		$	16,540
Restricted cash		116		—		—			116
U.S. government securities		18,743		5		(2	)		18,746
Level 2: U.S. agency securities		8,973		—		(13	)		8,960

Total financial assets	$	44,372	$	5	$	(15	)	$	44,362

Classified as:
Cash and cash equivalents								$	16,540
Restricted cash									116
Short-term investments									27,706

								$	44,362


	December 31, 2022
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Level 1: Money market funds	$	9,238	$	—	$	—		$	9,238
Restricted cash		382		—		—			382
U.S. government securities		30,761		—		(112	)		30,649
Level 2: U.S. agency securities		16,759		—		(78	)		16,681

Total financial assets	$	57,140	$	—	$	(190	)	$	56,950

Classified as:
Cash and cash equivalents								$	9,238
Restricted cash									382
Short-term investments									47,330

								$	56,950

While short-term investments are

available-for-sale,

it is not more likely than not that the Company will be required to sell the investments before recovery of their amortized cost bases, which may be maturity. All short-term investments currently held have maturities of less than one year.

The Company reviews short-term investments for impairment during each reporting period. Credit losses are recognized up to the amount equal to the difference between the fair value and the amortized cost basis and recorded as an allowance for credit losses in the unaudited condensed consolidated balance sheets with a corresponding adjustment to earnings. Unrealized losses that are not related to credit losses are recognized in accumulated other comprehensive loss. Unrealized losses were not significant for the investments held in the Company’s portfolio as of June 30, 2023 and Company considered the decline in market value for these securities to be primarily attributable to economic and market conditions rather than credit-related factors. The Company considered the risk-profile of the counterparties under ASU 2016-13, noting that any credit risk associated with such entities is either zero or near zero.

There were no impairment losses or expected credit losses related to its short-term investments during the three months and six months ended June 30, 2023 and 2022.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Nature of the Business and Basis of Presentation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands			3 Months Ended				6 Months Ended
	Aug. 15, 2023	Jul. 25, 2023	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Business Description And Basis Of Presentation [Line Items]
Common stock, shares authorized			147,892,358				147,892,358		147,892,358
Common stock par value			$ 0.001				$ 0.001		$ 0.001
Net income (loss)			$ 21,499	$ (68)	$ (11,600)	$ 12,616	$ 21,431	$ 1,016
Accumulated deficit			142,989				142,989		$ 121,558
Cash, cash equivalents, and short-term investments			$ 49,200				$ 49,200
Subsequent Event [Member]
Business Description And Basis Of Presentation [Line Items]
Description of the reverse stock split arrangement		1-for-7.9872
Number of new stock issued during the period	651,608
Shares issued, price per share	$ 12
Cash received on stock transaction after deduction of issuance costs	$ 7,300
Underwriting discounts and commissions	$ 500
Shares authorized		500,000,000
Common stock, shares authorized		490,000,000
Preferred stock, shares authorized		10,000,000
Common stock par value		$ 0.001
Preferred stock par value		$ 0.001
Proceeds from issuance initial public offering		$ 77,400
Subsequent Event [Member] \| IPO [Member]
Business Description And Basis Of Presentation [Line Items]
Number of new stock issued during the period		6,666,667
Shares issued, price per share		$ 12
Cash received on stock transaction after deduction of issuance costs		$ 70,100
Underwriting discounts and commissions		5,600
Other offering expenses		$ 4,300