# EDGAR Filing Document

**Accession Number:** 0001786442
**File Stem:** 0001415889-25-021964
**Filing Date:** 2025-8
**Character Count:** 7875
**Document Hash:** 46f798828b20404527bcba89d263d1d7
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001415889-25-021964.hdr.sgml**: 20250814

**ACCESSION NUMBER**: 0001415889-25-021964

**CONFORMED SUBMISSION TYPE**: 4

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20250814

**FILED AS OF DATE**: 20250814

**DATE AS OF CHANGE**: 20250814

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Topsoe Christina Teng
- **CENTRAL INDEX KEY:** 0001786442

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-39045
- **FILM NUMBER:** 251221188

**MAIL ADDRESS:**
- **STREET 1:** 325 E MIDDLEFIELD ROAD
- **CITY:** MOUNTAIN VIEW
- **STATE:** CA
- **ZIP:** 94043
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** IGM Biosciences, Inc.
- **CENTRAL INDEX KEY:** 0001496323
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 770349194
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **STREET 1:** 325 E MIDDLEFIELD ROAD
- **CITY:** MOUNTAIN VIEW
- **STATE:** CA
- **ZIP:** 94043
- **BUSINESS PHONE:** 650-965-7873

**MAIL ADDRESS:**
- **STREET 1:** 325 E MIDDLEFIELD ROAD
- **CITY:** MOUNTAIN VIEW
- **STATE:** CA
- **ZIP:** 94043

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** Palingen, Inc.
- **DATE OF NAME CHANGE:** 20100712

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

## FORM 4

### STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

[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**<sup>*</sup><br>Topsoe Christina Teng<br><sub>(Last) (First) (Middle)</sub><br>C/O IGM BIOSCIENCES, INC.<br>325 E. MIDDLEFIELD ROAD<br><sub>(Street)</sub><br>MOUNTAIN VIEW, CA 94043<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2025-08-14 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [X] 10% Owner<br>[ ] Officer (give title below) [ ] Other (specify below)<br>_ _ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>IGM Biosciences, Inc. [ IGMS ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[X] Form filed by One Reporting Person<br>[ ] Form filed by More than One Reporting Person |

---

## Table I - Non-Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | 3. Transaction Code (V) | 3. Transaction Code (V) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | Code | V | Amount | (A) or (D) | Price | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| Common Stock | 2025-08-14 |  | D |  | 54235<sup>(1)</sup> | D | <sup>(1)</sup> | 0 | D |  |
| Common Stock | 2025-08-14 |  | D |  | 10400564<sup>(1)</sup> | D | <sup>(1)</sup> | 0 | I | See footnote<sup>(2)</sup> |
| Common Stock | 2025-08-14 |  | D |  | 9800<sup>(1)</sup> | D | <sup>(1)</sup> | 0 | I | See footnote<sup>(3)</sup> |

---

## Table II - Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | 4. Transaction Code (V) | 4. Transaction Code (V) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 6. Date Exercisable and Expiration Date | 6. Date Exercisable and Expiration Date | 7. Title and Amount of Underlying Securities | 7. Title and Amount of Underlying Securities | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | Code | V | (A) | (D) | Date Exercisable | Expiration Date | Title | Amount or Number of Shares | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
| Non-Voting Common Stock<sup>(4)</sup> | <sup>(4)</sup> | 2025-08-14 |  | D |  |  | 5044295<sup>(1)</sup> | <sup>(4)</sup> | <sup>(4)</sup> | Common Stock | 5044295 | $0 | 0 | I | See footnote<sup>(2)</sup> |

---

### Footnotes:

(1) 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.

(2) 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.

(3) 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.

(4) 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.

**Signature:** /s/ Christina Teng Topsoe  
**Date:** 2025-08-14

### Remarks:

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).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

**Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.**