Mary Beth Harler - 14 Aug 2025 Form 4 Insider Report for IGM Biosciences, Inc. (IGMS)

Role: Chief Executive Officer, Director
Signature: /s/ Mary Beth Harler
Issuer symbol: IGMS
Transactions as of: 14 Aug 2025
Net transactions value: $0
Form type: 4
Filing time: 14 Aug 2025, 17:23:40 UTC
Previous filing: 25 Jul 2025
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Harler Mary Beth	Chief Executive Officer, Director	C/O IGM BIOSCIENCES, INC., 3 EAST THIRD AVENUE, SUITE 200, SAN MATEO	/s/ Mary Beth Harler	14 Aug 2025	0002018699

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	IGMS	Common Stock	Disposed to Issuer		-323,680	-100%		0	14 Aug 2025	Direct	F1

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

Mary Beth Harler is no longer subject to Section 16 filing requirements. Form 4 or Form 5 obligations may continue.

Explanation of Responses:

Id	Content
F1	Certain of these shares are represented by previously reported restricted stock units ("RSUs"). Pursuant to the Agreement and Plan of Merger dated July 1, 2025, by and among IGM Biosciences, Inc. (the "Company"), Concentra Biosciences, LLC, a Delaware limited liability company ("Parent"), and Concentra Merger Sub V, Inc., a Delaware corporation and a wholly owned subsidiary of Parent ("Merger Sub"), on August 14, 2025, Merger Sub merged with and into the Company (the "Merger"), with the Company continuing as the surviving corporation and a wholly owned subsidiary of Parent. In connection with the Merger, each issued and outstanding share of the Company's Common Stock, and each outstanding RSU, was cancelled and converted into the right to receive (i) an amount equal to $1.247 in cash and (ii) one contractual contingent value right (a "CVR") subject to the terms and conditions of a Contingent Value Rights Agreement.

Content

Certain of these shares are represented by previously reported restricted stock units ("RSUs"). Pursuant to the Agreement and Plan of Merger dated July 1, 2025, by and among IGM Biosciences, Inc. (the "Company"), Concentra Biosciences, LLC, a Delaware limited liability company ("Parent"), and Concentra Merger Sub V, Inc., a Delaware corporation and a wholly owned subsidiary of Parent ("Merger Sub"), on August 14, 2025, Merger Sub merged with and into the Company (the "Merger"), with the Company continuing as the surviving corporation and a wholly owned subsidiary of Parent. In connection with the Merger, each issued and outstanding share of the Company's Common Stock, and each outstanding RSU, was cancelled and converted into the right to receive (i) an amount equal to $1.247 in cash and (ii) one contractual contingent value right (a "CVR") subject to the terms and conditions of a Contingent Value Rights Agreement.