Christina Teng Topsoe - 14 Aug 2025 Form 4 Insider Report for IGM Biosciences, Inc. (IGMS)

Reporting relationship: Director, 10%+ Owner
Issuer ticker: IGMS
Reported as of: 14 Aug 2025
Net transaction value: $0
SEC form: 4
Accepted by SEC: 14 Aug 2025, 17:26:25 UTC
Prior SEC filing: 02 Jul 2025
Source filing: View source filing
Reporting owner signature: /s/ Christina Teng Topsoe

Key filing fact

Christina Teng Topsoe filed Form 4 for IGM Biosciences, Inc. (IGMS) on 14 Aug 2025.

Key facts

This page summarizes Christina Teng Topsoe's Form 4 filing for IGM Biosciences, Inc. (IGMS).
4 reported transactions and 1 derivative row are listed below.
Accepted by SEC: 14 Aug 2025, 17:26.

Change

Previous filing in this sequence was filed on 02 Jul 2025.
Current net transaction value: $0.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001786442 Primary reporting owner

Topsoe Christina Teng

Relationship: Director, 10%+ Owner
Address: C/O IGM BIOSCIENCES, INC., 325 E. MIDDLEFIELD ROAD, MOUNTAIN VIEW
Signature: /s/ Christina Teng Topsoe
Signature date: 14 Aug 2025

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

IGMS transaction

Common Stock

Disposed to Issuer

Transaction value
Shares: -54,235
Change %: -100%
Price
Shares after: 0
Date: 14 Aug 2025
Ownership: Direct
Footnotes: F1

IGMS transaction

Common Stock

Disposed to Issuer

Transaction value
Shares: -10,400,564
Change %: -100%
Price
Shares after: 0
Date: 14 Aug 2025
Ownership: See footnote
Footnotes: F1, F2

IGMS transaction

Common Stock

Disposed to Issuer

Transaction value
Shares: -9,800
Change %: -100%
Price
Shares after: 0
Date: 14 Aug 2025
Ownership: See footnote
Footnotes: F1, F3

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

IGMS transaction Derivative

Non-Voting Common Stock

Disposed to Issuer

Transaction value: $0
Shares: -5,044,295
Change %: -100%
Price: $0.000000
Shares after: 0
Date: 14 Aug 2025
Ownership: See footnote
Underlying class: Common Stock
Underlying amount: 5,044,295
Exercise price
Footnotes: F1, F2, F4

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Section 16 status

Christina Teng Topsoe is no longer subject to Section 16 filing requirements. Form 4 or Form 5 obligations may still apply in specific circumstances.

Explanation of responses 4 footnotes

Footnote F1

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 Non-Voting Common Stock 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.

Footnote F2

Prior to the Merger, the shares were held directly by Topsoe Holding A/S. Jakob Haldor Topsoe, Christina Teng Topsoe, Anne Haugwitz-Hardenberg-Reventlow, Emil Oigaard, Thomas Schleicher and Birgitte Nielsen, members of the board of directors of Topsoe Holding A/S, may be deemed to share voting and investment power with respect to the shares reported herein and disclaim beneficial ownership of such shares, except to the extent of his or her pecuniary interest therein, if any.

Footnote F3

Prior to the Merger, the shares were held by Pillarcater LLC. The Reporting Person is the sole manager of Pillarcater LLC, which is wholly owned by CT Foundation (a South Dakota Trust) of which the Reporting Person is the sole beneficiary.

Footnote F4

Prior to the Merger, the shares of Non-Voting Common Stock were convertible into the Issuer's Common Stock on a 1-for-1 basis (subject to a 4.99% beneficial ownership limitation that may be increased or decreased by the holder of such shares) and had no expiration date.