# EDGAR Filing Document

**Accession Number:** 0001315797
**File Stem:** 0000895345-25-000365
**Filing Date:** 2025-11
**Character Count:** 6446
**Document Hash:** aee1c63dc81f2c8207cbaa442a93f6ce
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0000895345-25-000365.hdr.sgml**: 20251121

**ACCESSION NUMBER**: 0000895345-25-000365

**CONFORMED SUBMISSION TYPE**: SCHEDULE 13D/A

**PUBLIC DOCUMENT COUNT**: 1

**FILED AS OF DATE**: 20251121

**DATE AS OF CHANGE**: 20251121

**SUBJECT COMPANY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Annexon, Inc.
- **CENTRAL INDEX KEY:** 0001528115
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 275414423
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13D/A
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 005-91583
- **FILM NUMBER:** 251509344

**BUSINESS ADDRESS:**
- **STREET 1:** 1400 SIERRA POINT PARKWAY
- **STREET 2:** BLDG C, SUITE 200
- **CITY:** BRISBANE
- **STATE:** CA
- **ZIP:** 94005
- **BUSINESS PHONE:** (650) 822-5500

**MAIL ADDRESS:**
- **STREET 1:** 1400 SIERRA POINT PARKWAY
- **STREET 2:** BLDG C, SUITE 200
- **CITY:** BRISBANE
- **STATE:** CA
- **ZIP:** 94005
**FILED BY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Satter Muneer A
- **CENTRAL INDEX KEY:** 0001315797

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13D/A

**MAIL ADDRESS:**
- **STREET 1:** C/O SATTER INVESTMENT MANAGEMENT, LLC
- **STREET 2:** 676 NORTH MICHIGAN AVENUE, SUITE 4000
- **CITY:** CHICAGO
- **STATE:** IL
- **ZIP:** 60611

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

## SCHEDULE 13D

### Under the Securities Exchange Act of 1934

**(Amendment No. 2)**

**Annexon, Inc.**

*(Name of Issuer)*

**Common Stock, par value $0.001**

*(Title of Class of Securities)*

**03589W102**

*(CUSIP Number)*

**Muneer A. Satter**<br>c/o Alerce Investment Management, L.P.<br>676 N. Michigan Avenue, Suite 4000<br>Chicago IL 60611<br>312-448-5500

*(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)*

**11/19/2025**

*(Date of Event Which Requires Filing of this Statement)*

| **CUSIP No.** | **03589W102** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**Satter Muneer A** | Name of reporting person<br>**Satter Muneer A** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**OO** | Source of funds (See Instructions)<br>**OO** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**X1** | Citizenship or place of organization<br>**X1** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**10444134.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**10444134.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**0.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**10444134.00** | Aggregate amount beneficially owned by each reporting person<br>**10444134.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**7.2%** | Percent of class represented by amount in Row (11)<br>**7.2%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**IN** | Type of Reporting Person (See Instructions)<br>**IN** | |

---

**Item 1. Security and Issuer**

**(a) Title of Class of Securities:**
Common Stock, par value $0.001

**(b) Name of Issuer:**
Annexon, Inc.

**(c) Address of Issuer's Principal Executive Offices:**
c/o Alerce Investment Management, L.P., 676 N. Michigan Avenue, Suite 4000, Chicago, IL, 60611

This Amendment No. 2 ("Amendment No. 2") amends and supplements the statement on Schedule 13D filed on July 18, 2022 (the "Original Filing") by Muneer A. Satter with respect to the common stock, par value $0.001 per share (the "Common Stock"), of Annexon, Inc. (the "Company"), as previously amended by Amendment No. 1 on February 17, 2023. The Original Filing as previously amended remains in effect except to the extent that it is amended, restated or superseded by information contained in this Amendment No. 2. Capitalized terms used and not defined in this Amendment No. 2 have the meanings set forth in the Original Filing as previously amended.

**Item 5. Interest in Securities of the Issuer**

**(a)**
Item 5(a) is amended and restated as follows:

See Items 11 and 13 of the cover pages.

The aggregate percentage of Common Stock beneficially owned by Mr. Satter is based upon 145,261,154 shares outstanding, including 144,545,657 shares outstanding as disclosed by the Issuer on November 13, 2025 in a Prospectus Supplement filed with the SEC pursuant to Rule 424(b)(5), 613,497 shares of Common Stock that may be acquired upon the exercise of Common Warrants held by Alerce Medical, and 102,000 shares of Common Stock that may be acquired within 60 days of the date hereof pursuant to the exercise of stock options held by Mr. Satter.

**(b)**
Item 5(b) is amended and restated as follows:

See Items 7, 8, 9 and 10 of the cover pages.

**(c)**
Item 5(c) is amended by the addition of the following tabular presentation of daily purchases of shares of Common Stock made for cash on the Nasdaq; in each case the daily average price is reported.

November 17, 2025: 500,000 shares $2.99
November 18, 2025: 500,000 shares $3.18
November 19, 2025: 500,000 shares $3.94
November 20, 2025: 400,000 shares $4.48
November 21, 2025: 422,613 shares $4.28

### SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

**Reporting Person:** Satter Muneer A

**Signature:** /s/ Muneer Satter

**Name/Title:** Satter Muneer A

**Date:** 11/21/2025