SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person* ORBIMED ADVISORS LLC (Last) (First) (Middle) 601 LEXINGTON AVENUE, 54TH FLOOR (Street) NEW YORK NY 10022 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 07/20/2023	3. Issuer Name and Ticker or Trading Symbol Turnstone Biologics Corp. [ TSBX ]
		4. Relationship of Reporting Person(s) to Issuer (Check all applicable) X Director X 10% Owner Officer (give title below) Other (specify below)	5. If Amendment, Date of Original Filed (Month/Day/Year)
			6. Individual or Joint/Group Filing (Check Applicable Line) Form filed by One Reporting Person X Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Series B-1 Preferred Stock	(1)	(1)	Common Stock	937,372	(1)	I	See footnotes(2)(3)
Series B-2 Preferred Stock	(1)	(1)	Common Stock	1,249,829	(1)	I	See footnotes(2)(3)
Series C Preferred Stock	(1)	(1)	Common Stock	266,240	(1)	I	See footnotes(2)(3)
Series D Preferred Stock	(1)	(1)	Common Stock	229,158	(1)	I	See footnotes(2)(3)

1. Name and Address of Reporting Person* ORBIMED ADVISORS LLC (Last) (First) (Middle) 601 LEXINGTON AVENUE, 54TH FLOOR (Street) NEW YORK NY 10022 (City) (State) (Zip)

1. Name and Address of Reporting Person* OrbiMed Capital GP VI LLC (Last) (First) (Middle) 601 LEXINGTON AVENUE, 54TH FLOOR (Street) NEW YORK NY 10022 (City) (State) (Zip)

Explanation of Responses:

1. Each share of Series B-1 Preferred Stock, Series, Series B-2 Preferred Stock, Series C Preferred Stock and Series D Preferred Stock will automatically convert into shares of Common Stock on a 7.9872 for 1 basis immediately prior to the closing of the Issuer's initial public offering and have no expiration date.

2. These securities are held of record by OrbiMed Private Investments VI, LP ("OPI VI"). OrbiMed Capital GP VI LLC ("GP VI") is the general partner of OPI VI and OrbiMed Advisors LLC ("OrbiMed Advisors") is the managing member of GP VI. By virtue of such relationships, OrbiMed Advisors and GP VI may be deemed to have voting power and investment power over the securities held by OPI VI and, as a result, may be deemed to have beneficial ownership over such securities. OrbiMed Advisors exercises voting and investment power through a management committee comprised of Carl L. Gordon, Sven H. Borho, and W. Carter Neild, each of whom disclaims beneficial ownership of the securities held by OPI VI.

3. Each of OrbiMed Advisors and GP VI disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of its pecuniary interest therein, if any. OrbiMed Advisors and GP VI have designated a representative, Rishi Gupta, an employee of OrbiMed Advisors, to serve on the Issuer's board of directors. This report shall not be deemed an admission that any such person or entity is a beneficial owner of such securities for the purpose of Section 16 of the Exchange Act, or for any other purpose.

Remarks:

	OrbiMed Advisors LLC, By /s/ Douglas Coon, Chief Compliance Officer	07/20/2023
	OrbiMed Capital GP VI LLC, By /s/ Douglas Coon, Chief Compliance Officer	07/20/2023
	** Signature of Reporting Person	Date
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