# EDGAR Filing Document

**Accession Number:** 0001496323
**File Stem:** 0001104659-25-078832
**Filing Date:** 2025-8
**Character Count:** 7915
**Document Hash:** af5c7ee673a6ee428d3e124a18d9ae57
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001104659-25-078832.hdr.sgml**: 20250814

**ACCESSION NUMBER**: 0001104659-25-078832

**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:** Lee Michael Stewart
- **CENTRAL INDEX KEY:** 0001748010

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-39045
- **FILM NUMBER:** 251221931

**MAIL ADDRESS:**
- **STREET 1:** C/O REDMILE GROUP, LLC
- **STREET 2:** ONE LETTERMAN DR., BLDG. D, SUITE D3-300
- **CITY:** SAN FRANCISCO
- **STATE:** CA
- **ZIP:** 94129
**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>Lee Michael Stewart<br><sub>(Last) (First) (Middle)</sub><br>C/O REDMILE GROUP, LLC<br>ONE LETTERMAN DR., BLDG. D, SUITE D3-300<br><sub>(Street)</sub><br>SAN FRANCISCO, CA 94129<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 [ ] 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 |  | 12712<sup>(1)</sup> | D | <sup>(1)</sup> | 0 | D<sup>(2)(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 |
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |

---

### Footnotes:

(1) On August 14, 2025, pursuant to the terms of the Agreement and Plan of Merger, dated as of July 1, 2025, among the Issuer, 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"), Merger Sub completed a tender offer to purchase all outstanding shares of the Issuer's Common Stock and Non-Voting Common Stock in exchange for (a) a price per share of $1.247 in cash (the "Offer Price"), subject to applicable tax withholding and without interest, plus (b) one contingent value right ("CVR") per share subject to the terms and conditions of a Contingent Value Rights Agreement . The tender offer expired one minute following 11:59 p.m., Eastern Time, on August 13, 2025 (the "Offer Closing").

(2) The reported securities were granted to Michael Lee, a managing director of Redmile Group, LLC ("Redmile"), in connection with his service as a member of the Board of Directors of the Issuer. Pursuant to the policies of Redmile, Mr. Lee held these securities as a nominee on behalf, and for the sole benefit, of Redmile and assigned all economic, pecuniary and voting rights in respect of the securities to Redmile. Mr. Lee disclaimed beneficial ownership of the reported securities, and the filing of this Form 4 shall not be deemed an admission that Mr. Lee was the beneficial owner of the securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose.

(3) The securities may also be deemed beneficially owned by Jeremy Green as the principal of Redmile. Redmile and Mr. Green disclaim beneficial ownership of the securities except to the extent of their pecuniary interest therein, if any, and this Form 4 shall not be deemed an admission that Redmile or Mr. Green is the beneficial owner of the securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose.

**Remarks:**
Mr. Lee, a managing director of Redmile, resigned as a member of the board of directors of the Issuer immediately prior to the effective date and time of the merger between Issuer and Merger Sub.

**Signature:** /s/ Michael Lee  
**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.**