Fairmount Funds Management LLC - Jun 10, 2025 Form 4 Insider Report for Zenas BioPharma, Inc. (ZBIO)

Role: Director
Signature: By: /s/ Tomas Kiselak, Managing Member of Fairmount Funds Management LLC
Stock symbol: ZBIO
Transactions as of: Jun 10, 2025
Transactions value $: $0
Form type: 4
Date filed: 6/12/2025, 04:34 PM
Previous filing: Jun 11, 2025
Next filing: Jun 23, 2025
SEC: View on sec.gov

Reporting Owners (4)

Name	Relationship	Address	Signature	Signature date	CIK
Fairmount Funds Management LLC	Director	200 BARR HARBOR DRIVE, SUITE 400, WEST CONSHOHOCKEN	By: /s/ Tomas Kiselak, Managing Member of Fairmount Funds Management LLC	2025-06-12	0001802528
Fairmount Healthcare Fund II L.P.	Director	200 BARR HARBOR DRIVE, SUITE 400, WEST CONSHOHOCKEN	By: /s/ Tomas Kiselak, Managing Member of Fairmount Healthcare Fund II LP	2025-06-12	0001769651
Kiselak Tomas	Director	200 BARR HARBOR DRIVE, SUITE 400, WEST CONSHOHOCKEN	By: /s/ Tomas Kiselak	2025-06-12	0001830177
Harwin Peter Evan	Director	200 BARR HARBOR DRIVE, SUITE 400, WEST CONSHOHOCKEN	By: /s/ Peter Harwin	2025-06-12	0001663607

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	ZBIO	Stock Option (Right to Buy)	Award	$0	+18.5K		$0.00	18.5K	Jun 10, 2025	Common Stock	18.5K	$11.94	By Tomas Kiselak	F1, F2

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	The option vests as to 100% of the underlying shares of common stock on June 10, 2026, the first anniversary of the vesting commencement date, subject to continued service.
F2	Under Mr. Kiselak's arrangement with Fairmount, Mr. Kiselak holds the option for one or more investment vehicles managed by Fairmount Funds Management LLC ("Fairmount" and each such investment vehicle, a "Fairmount Fund"). Mr. Kiselak is obligated to turn over to Fairmount any net cash or stock received from the option for the benefit of such Fairmount Fund. Mr. Kiselak therefore disclaims beneficial ownership of the option and underlying common stock. Fairmount disclaims beneficial ownership of any of the reported securities, except to the extent of its pecuniary interest therein.

Content

The option vests as to 100% of the underlying shares of common stock on June 10, 2026, the first anniversary of the vesting commencement date, subject to continued service.

Under Mr. Kiselak's arrangement with Fairmount, Mr. Kiselak holds the option for one or more investment vehicles managed by Fairmount Funds Management LLC ("Fairmount" and each such investment vehicle, a "Fairmount Fund"). Mr. Kiselak is obligated to turn over to Fairmount any net cash or stock received from the option for the benefit of such Fairmount Fund. Mr. Kiselak therefore disclaims beneficial ownership of the option and underlying common stock. Fairmount disclaims beneficial ownership of any of the reported securities, except to the extent of its pecuniary interest therein.

Remarks:

Fairmount and Fairmount Healthcare Fund II L.P. may each be deemed a director by deputization of the Issuer by virtue of the fact that Tomas Kiselak serves on the board of directors of the Issuer and is a Managing Member of Fairmount.