[Form 4] Turnstone Biologics Corp. Insider Trading Activity

Rhea-AI Filing Summary

Versant-affiliated entities reported dispositions of Turnstone Biologics common stock on 08/08/2025 pursuant to an Agreement and Plan of Merger dated June 26, 2025 under which XOMA Royalty Corporation completed a cash tender offer for all outstanding shares at $0.34 per share plus one non-transferable contractual contingent value right (CVR) per share. The Form 4 shows post-transaction indirect beneficial ownership retained by Versant vehicles: 2,726,322 shares held by Versant Venture Capital V, L.P., 207,486 by Versant Venture Capital V (Canada) LP, 90,888 by Versant Ophthalmic Affiliates Fund I, L.P., 82,006 by Versant Affiliates Fund V, L.P., and 274,990 by Versant Vantage II, L.P. The filing was signed on 08/12/2025 by Max Eisenberg as Chief Operating Officer.

Positive

• Transaction completed under a defined merger/tender framework with disclosed consideration of $0.34 per share plus one CVR, providing clear terms
• Detailed post-transaction holdings disclosed, showing substantive retained indirect positions (e.g., 2,726,322 shares held by Versant Venture Capital V, L.P.)

Negative

• Significant disposals occurred—transactions were dispositions pursuant to the Agreement and Plan of Merger, reducing direct holdings by the reporting entities
• Potential concentration of control remains with affiliated entities as general partners and a director are disclosed to share voting and dispositive power, which may complicate independence assessments

Insights

Financial Analyst

TL;DR: Versant entities disposed shares via a merger-related tender offer at $0.34 plus a CVR; several funds retain material indirect stakes.

The reported transactions on 08/08/2025 were dispositions made pursuant to the Agreement and Plan of Merger with XOMA Royalty Corporation, which offered $0.34 per share plus one CVR. The Form 4 shows that multiple Versant funds continue to hold significant indirect positions—most notably 2.73 million shares via Versant Venture Capital V, L.P.—indicating partial retention of exposure post-offer. The disclosure is procedural and documents the mechanics of the tender and residual holdings rather than operational results.

Corporate Governance Expert

TL;DR: Filing documents a merger-related disposition across affiliated funds and clarifies shared voting/dispositive power among general partners and a board director.

The explanatory notes specify the ownership chains and disclaimers: general partners and an Issuer director may be deemed to share voting and dispositive power over the reported holdings but disclaim beneficial ownership except for pecuniary interest. This Form 4 clarifies post-transaction beneficial ownership and governance links among Versant entities and a director who files separate Section 16 reports. The filing enhances transparency about which entities retain indirect stakes after the tender offer.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
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X

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Versant Ventures V, LLC

(Last) (First) (Middle)

ONE SANSOME STREET, SUITE 1650

(Street)

SAN FRANCISCO CA 94104

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Turnstone Biologics Corp. [ TSBX ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
08/08/2025

4. 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 Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	08/08/2025		U(1)		2,726,322	D	(1)	0	I	By Versant Venture Capital V, L.P.(2)
Common Stock	08/08/2025		U(1)		207,486	D	(1)	0	I	By Versant Venture Capital V (Canada) LP(3)
Common Stock	08/08/2025		U(1)		90,888	D	(1)	0	I	By Versant Ophthalmic Affiliates Fund I, L.P.(4)
Common Stock	08/08/2025		U(1)		82,006	D	(1)	0	I	By Versant Affiliates Fund V, L.P.(5)
Common Stock	08/08/2025		U(1)		274,990	D	(1)	0	I	By Versant Vantage II, L.P.(6)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

1. Name and Address of Reporting Person^*

Versant Ventures V, LLC

(Last) (First) (Middle)

ONE SANSOME STREET, SUITE 1650

(Street)

SAN FRANCISCO CA 94104

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

Versant Venture Capital V, L.P.

(Last) (First) (Middle)

ONE SANSOME STREET, SUITE 1650

(Street)

SAN FRANCISCO CA 94104

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

Versant Ophthalmic Affiliates I, L.P.

(Last) (First) (Middle)

ONE SANSOME STREET, SUITE 1650

(Street)

SAN FRANCISCO CA 94104

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

Versant Affiliates Fund V, L.P.

(Last) (First) (Middle)

ONE SANSOME STREET, SUITE 1650

(Street)

SAN FRANCISCO CA 94104

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

Versant Ventures V GP-GP (Canada), Inc.

(Last) (First) (Middle)

ONE SANSOME STREET, SUITE 1650

(Street)

SAN FRANCISCO CA 94104

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

Versant Ventures V (Canada), L.P.

(Last) (First) (Middle)

ONE SANSOME STREET, SUITE 1650

(Street)

SAN FRANCISCO CA 94104

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

Versant Venture Capital V (Canada), LP

(Last) (First) (Middle)

ONE SANSOME STREET, SUITE 1650

(Street)

SAN FRANCISCO CA 94104

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

Versant Vantage II GP-GP, LLC

(Last) (First) (Middle)

ONE SANSOME STREET, SUITE 1650

(Street)

SAN FRANCISCO CA 94104

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

Versant Vantage II GP, L.P.

(Last) (First) (Middle)

ONE SANSOME STREET, SUITE 1650

(Street)

SAN FRANCISCO CA 94104

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

Versant Vantage II, L.P.

(Last) (First) (Middle)

ONE SANSOME STREET, SUITE 1650

(Street)

SAN FRANCISCO CA 94104

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

Explanation of Responses:

1. Disposed of pursuant to the terms of the Agreement and Plan of Merger, dated June 26, 2025, by and among the Issuer, XOMA Royalty Corporation ("Purchaser") and XRA 3 Corp., a wholly-owned subsidiary of Purchaser, pursuant to which Purchaser completed a cash tender offer (the "Offer")for all outstanding shares of common stock of the Issuer for (i) $0.34 per share in cash, payable subject to any applicable tax withholding and without interest, plus (ii) one non-transferable contractual contingent value right per share, payable subject to any applicable tax withholding and without interest.

2. Shares are held by Versant Venture Capital V, L.P. ("Versant V"). Versant Ventures V, LLC ("Versant V GP") is the sole general partner of Versant V. Jerel C. Davis ("Dr. Davis"), a member of the Issuer's board of directors, is a managing director of Versant V GP. Each of Versant V GP and Dr. Davis may be deemed to share voting and dispositive power over the shares held by Versant V, and each disclaims beneficial ownership of the shares held by Versant V, except to the extent of their respective pecuniary interest therein. Dr. Davis is a director of the Issuer and files separate Section 16 reports.

3. Shares are held by Versant Venture Capital V (Canada) LP ("Canada V"). Versant Ventures V (Canada), L.P. ("Canada V GP") is the general partner of Canada V and Versant Ventures V GP-GP (Canada), Inc. ("Canada V GP-GP") is the sole general partner of Canada V GP. Dr. Davis, a member of the Issuer's board of directors, is a director of Canada V GP-GP. Each of Canada V GP-GP, Canada V GP and Dr. Davis may be deemed to share voting and dispositive power over the shares held by Canada V, and each disclaims beneficial ownership of the shares held by Canada V, except to the extent of their respective pecuniary interest therein. Dr. Davis is a director of the Issuer and files separate Section 16 reports.

4. Shares are held by Versant Ophthalmic Affiliates Fund I, L.P. ("Ophthalmic"). Versant V GP is the sole general partner of Ophthalmic. Dr. Davis, a member of the Issuer's board of directors, is a managing director of Versant V GP. Each of Versant V GP and Dr. Davis may be deemed to share voting and dispositive power over the shares held by Ophthalmic, and each disclaims beneficial ownership of the shares held by Ophthalmic, except to the extent of their respective pecuniary interest therein. Dr. Davis is a director of the Issuer and files separate Section 16 reports.

5. Shares are held by Versant Affiliates Fund V, L.P. ("Affiliates V"). Versant V GP is the sole general partner of Affiliates V. Dr. Davis, a member of the Issuer's board of directors, is a managing director of Versant V GP. Each of Versant V GP and Dr. Davis may be deemed to share voting and dispositive power over the shares held by Affiliates V, and each disclaims beneficial ownership of the shares held by Affiliates, except to the extent of their respective pecuniary interest therein. Dr. Davis is a director of the Issuer and files separate Section 16 reports.

6. Shares held by Versant Vantage II, L.P. ("Vantage II"). Versant Vantage II GP, L.P. ("Vantage II GP") is the sole general partner of Vantage II and Versant Vantage II GP-GP, LLC ("Vantage II GP-GP") is the sole general partner of Vantage II GP. Dr. Davis, a member of the Issuer's board of directors, is a managing director of Vantage II GP-GP. Each of Vantage II GP-GP, Vantage II GP and Dr. Davis may be deemed to share voting and dispositive power over the shares held by Vantage II, and each disclaims beneficial ownership of the shares held by Canada V, except to the extent of their respective pecuniary interest therein. Dr. Davis is a director of the Issuer and files separate Section 16 reports.

	Versant Ventures V, LLC, By /s/ Max Eisenberg, Chief Operating Officer	08/12/2025
	Versant Venture Capital V, L.P., By Versant Ventures V, LLC, its general partner, By /s/ Max Eisenberg, Chief Operating Officer	08/12/2025
	Versant Ophthalmic Affiliates Fund I, L.P., By Versant Ventures V, LLC, its general partner, By /s/ Max Eisenberg, Chief Operating Officer	08/12/2025
	Versant Affiliates Fund V, L.P., By Versant Ventures V, LLC, its general partner, By /s/ Max Eisenberg, Chief Operating Officer	08/12/2025
	Versant Ventures V GP-GP (Canada), Inc., By /s/ Max Eisenberg, Chief Operating Officer	08/12/2025
	Versant Ventures V (Canada), L.P., By Versant Ventures V GP-GP (Canada), Inc., its general partner, By /s/ Max Eisenberg, Chief Operating Officer	08/12/2025
	Versant Venture Capital V (Canada), LP, By Versant Ventures V (Canada), L.P., its general partner, By Versant Ventures V GP-GP (Canada), Inc., its general partner, By /s/ Max Eisenberg, Chief Operating Officer	08/12/2025
	Versant Vantage II GP-GP, LLC, By /s/ Max Eisenberg, Chief Operating Officer	08/12/2025
	Versant Vantage II GP, L.P., By Versant Vantage II GP-GP, LLC, its general partner, By /s/ Max Eisenberg, Chief Operating Officer	08/12/2025
	Versant Vantage II, L.P., By Versant Vantage II GP, L.P., its general partner, By Versant Vantage II GP-GP, LLC, its general partner, By /s/ Max Eisenberg, Chief Operating Officer	08/12/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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FAQ

What did the Form 4 filed for Turnstone Biologics (TSBX) report?

The Form 4 reported that Versant-affiliated entities disposed shares on 08/08/2025 pursuant to a merger/tender offer and disclosed remaining indirect holdings by each fund.

What was the consideration in the tender offer described in the filing?

The tender offer consideration was $0.34 per share in cash payable subject to tax withholding plus one non-transferable contractual contingent value right (CVR) per share.

How many shares does Versant Venture Capital V, L.P. report holding after the transaction?

Versant Venture Capital V, L.P. reported holding 2,726,322 shares beneficially following the reported transaction.

When were the transactions and the Form 4 signature dated?

The transactions are reported with a transaction date of 08/08/2025 and the Form 4 was signed on 08/12/2025 by Max Eisenberg, Chief Operating Officer.

Do the filings indicate shared voting or dispositive power among affiliated parties?

Yes. The explanatory notes state that general partners and a director may be deemed to share voting and dispositive power over the reported shares, though they disclaim beneficial ownership except for pecuniary interest.