# EDGAR Filing Document

**Accession Number:** 0001425738
**File Stem:** 0001104659-26-016434
**Filing Date:** 2026-2
**Character Count:** 20997
**Document Hash:** c9cfbbfede9877c8c91184529ec8c365
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001104659-26-016434.hdr.sgml**: 20260217

**ACCESSION NUMBER**: 0001104659-26-016434

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

**PUBLIC DOCUMENT COUNT**: 1

**FILED AS OF DATE**: 20260217

**DATE AS OF CHANGE**: 20260217

**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 13G/A
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 005-91583
- **FILM NUMBER:** 26641517

**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:** Redmile Group, LLC
- **CENTRAL INDEX KEY:** 0001425738

**ORGANIZATION NAME:**
- **EIN:** 208592298
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

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

**BUSINESS ADDRESS:**
- **STREET 1:** ONE LETTERMAN DRIVE
- **STREET 2:** BUILDING D, SUITE D3-300
- **CITY:** SAN FRANCISCO
- **STATE:** CA
- **ZIP:** 94129
- **BUSINESS PHONE:** 415-489-9980

**MAIL ADDRESS:**
- **STREET 1:** ONE LETTERMAN DRIVE
- **STREET 2:** BUILDING D, SUITE D3-300
- **CITY:** SAN FRANCISCO
- **STATE:** CA
- **ZIP:** 94129

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

## SCHEDULE 13G

### Under the Securities Exchange Act of 1934

**(Amendment No. 5)**

**Issuer:** Annexon, Inc.

**Title of Class of Securities:** Common Stock, par value $0.001 per share

**CUSIP Number:** 03589W102

**Date of Event Which Requires Filing of this Statement:** 12/31/2025

**Check the appropriate box to designate the rule pursuant to which this Schedule is filed:**

- [ ] Rule 13d-1(b)

- [x] Rule 13d-1(c)

- [ ] Rule 13d-1(d)

---

| 1. | Names of Reporting Persons<br>Redmile Group, LLC | Names of Reporting Persons<br>Redmile Group, LLC |
|:---|:---|:---|:---|
| 2. | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [ ] | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [ ] |
| 3. | SEC Use Only | SEC Use Only |
| 4. | Citizenship or Place of Organization<br>DE | Citizenship or Place of Organization<br>DE |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 5. | Sole Voting Power<br>0.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 6. | Shared Voting Power<br>15427866.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 7. | Sole Dispositive Power<br>0.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 8. | Shared Dispositive Power<br>15427866.00 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>15427866.00 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>15427866.00 |
| 10. | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] |
| 11. | Percent of Class Represented by Amount in Row (9)<br>9.9% | Percent of Class Represented by Amount in Row (9)<br>9.9% |
| 12. | Type of Reporting Person (See Instructions)<br>IA, OO | Type of Reporting Person (See Instructions)<br>IA, OO |

**Comment for Type of Reporting Person:** Redmile Group, LLC's beneficial ownership of the Issuer's common stock ("Common Stock") is comprised of 10,050,644 shares of Common Stock owned by certain private investment vehicles managed by Redmile Group, LLC (the "Redmile Clients"), including Redmile Biopharma Investments II, L.P. ("RBI II"). Subject to the Beneficial Ownership Blocker (as defined below), Redmile Group, LLC may also be deemed to beneficially own 45,109,195 shares of Common Stock issuable upon exercise of certain pre-funded warrants to purchase Common Stock (the "Warrants"). Pursuant to the terms of the Warrants, the Issuer may not effect any exercise of the Warrant, and a holder of a Warrant does not have the right to exercise the Warrant held by such holder, to the extent that after giving effect to such issuance after exercise, the holder (together with the holder's affiliates, and any other persons acting as a group together with the holder or any of the holder's affiliates), would beneficially own in excess of 9.99% (the "Beneficial Ownership Limitation") of the number of shares of Common Stock outstanding immediately after giving effect to the issuance of shares of Common Stock issued upon exercise of the Warrant (the "Beneficial Ownership Blocker"). The Beneficial Ownership Limitation may be changed at a holder's election upon 61 days' notice to the Issuer. The 15,427,866 shares of Common Stock reported as beneficially owned by Redmile Group, LLC in this Schedule 13G represent 9.99% of the outstanding shares of Common Stock (calculated in accordance with the footnote below), which includes 5,377,222 shares of Common Stock that could be issued upon exercise of certain of the Warrants under the Beneficial Ownership Blocker. The reported securities may be deemed beneficially owned by Redmile Group, LLC as investment manager of the Redmile Clients. The reported securities may also be deemed beneficially owned by Jeremy C. Green as the principal of Redmile Group, LLC. Redmile Group, LLC and Mr. Green each disclaim beneficial ownership of these shares, except to the extent of its or his pecuniary interest in such shares, if any.

Percentage based on: (i) 119,632,804 shares of Common Stock outstanding as of November 5, 2025, as reported by the Issuer in its Form 10-Q for the quarterly period ended September 30, 2025 filed with the SEC on November 10, 2025 (the "Form 10-Q"); plus (ii) 29,423,075 shares of Common Stock issued and sold as of November 14, 2025, as reported by the Issuer in its Form 8-K filed with the SEC on November 14, 2025 (the "Form 8-K"); plus (iii) 5,377,222 shares of Common Stock issuable upon exercise of the Warrants, which due to the Beneficial Ownership Limitation is the maximum number of shares that could be issued upon exercise of the Warrants.

---

| 1. | Names of Reporting Persons<br>Jeremy C. Green | Names of Reporting Persons<br>Jeremy C. Green |
|:---|:---|:---|:---|
| 2. | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [ ] | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [ ] |
| 3. | SEC Use Only | SEC Use Only |
| 4. | Citizenship or Place of Organization<br>X0 | Citizenship or Place of Organization<br>X0 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 5. | Sole Voting Power<br>0.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 6. | Shared Voting Power<br>15427866.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 7. | Sole Dispositive Power<br>0.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 8. | Shared Dispositive Power<br>15427866.00 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>15427866.00 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>15427866.00 |
| 10. | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] |
| 11. | Percent of Class Represented by Amount in Row (9)<br>9.9% | Percent of Class Represented by Amount in Row (9)<br>9.9% |
| 12. | Type of Reporting Person (See Instructions)<br>HC, IN | Type of Reporting Person (See Instructions)<br>HC, IN |

**Comment for Type of Reporting Person:** Jeremy C. Green's beneficial ownership of Common Stock is comprised of 10,050,644 shares of Common Stock owned by the Redmile Clients, including RBI II. Subject to the Beneficial Ownership Blocker, Mr. Green may also be deemed to beneficially own 45,109,195 shares of Common Stock issuable upon exercise of the Warrants. Pursuant to the terms of the Warrants, the Issuer may not effect any exercise of the Warrant, and a holder of a Warrant does not have the right to exercise the Warrant held by such holder, to the extent that the Beneficial Ownership Blocker applies. The 15,427,866 shares of Common Stock reported as beneficially owned by Mr. Green in this Schedule 13G represent 9.99% of the outstanding shares of Common Stock (calculated in accordance with the footnote below), which includes 5,377,222 shares of Common Stock that could be issued upon exercise of certain of the Warrants under the Beneficial Ownership Blocker. The reported securities may be deemed beneficially owned by Redmile Group, LLC as investment manager of the Redmile Clients. The reported securities may also be deemed beneficially owned by Jeremy C. Green as the principal of Redmile Group, LLC. Redmile Group, LLC and Mr. Green each disclaim beneficial ownership of these shares, except to the extent of its or his pecuniary interest in such shares, if any.

Percentage based on: (i) 119,632,804 shares of Common Stock outstanding as of November 5, 2025, as reported in the Form 10-Q; plus (ii) 29,423,075 shares of Common Stock issued and sold as of November 14, 2025, as reported in the Form 8-K; plus (iii) 5,377,222 shares of Common Stock issuable upon exercise of the Warrants, which due to the Beneficial Ownership Limitation is the maximum number of shares that could be issued upon exercise of the Warrants.

---

| 1. | Names of Reporting Persons<br>Redmile Biopharma Investments II, L.P. | Names of Reporting Persons<br>Redmile Biopharma Investments II, L.P. |
|:---|:---|:---|:---|
| 2. | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [ ] | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [ ] |
| 3. | SEC Use Only | SEC Use Only |
| 4. | Citizenship or Place of Organization<br>DE | Citizenship or Place of Organization<br>DE |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 5. | Sole Voting Power<br>0.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 6. | Shared Voting Power<br>7288917.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 7. | Sole Dispositive Power<br>0.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 8. | Shared Dispositive Power<br>7288917.00 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>7288917.00 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>7288917.00 |
| 10. | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] |
| 11. | Percent of Class Represented by Amount in Row (9)<br>4.7% | Percent of Class Represented by Amount in Row (9)<br>4.7% |
| 12. | Type of Reporting Person (See Instructions)<br>PN | Type of Reporting Person (See Instructions)<br>PN |

**Comment for Type of Reporting Person:** RBI II's beneficial ownership of Common Stock is comprised of 1,911,695 shares of Common Stock directly held by RBI II. Subject to the Beneficial Ownership Blocker, RBI II may also be deemed to beneficially own 6,702,359 shares of Common Stock issuable upon exercise of the Warrants directly held by RBI II. Pursuant to the terms of the Warrants, the Issuer may not effect any exercise of any Warrant, and a holder of a Warrant does not have the right to exercise any portion of the Warrant held by such holder, if the Beneficial Ownership Blocker applies. The shares of Common Stock reported as beneficially owned by RBI II in this Schedule 13G represent the shares of Common Stock held directly by RBI II and the 5,377,222 shares of Common Stock that could be issued to RBI II upon exercise of certain of the Warrants directly held by RBI II under the Beneficial Ownership Blocker.

Percentage based on: (i) 119,632,804 shares of Common Stock outstanding as of November 5, 2025, as reported in the Form 10-Q; plus (ii) 29,423,075 shares of Common Stock issued and sold as of November 14, 2025, as reported in the Form 8-K; plus (iii) 5,377,222 shares of Common Stock issuable upon exercise of the Warrants directly held by RBI II, which due to the Beneficial Ownership Limitation is the maximum number of shares that could be issued upon exercise of the Warrants.

---

**Item 1(a). Name of Issuer:**
Annexon, Inc.

**Item 1(b). Address of Issuer's Principal Executive Offices:**
1400 Sierra Point Parkway, Bldg C, Suite 200, Brisbane, CA 94005

**Item 2(a). Name of Person Filing:**
Redmile Group, LLC
Jeremy C. Green
Redmile Biopharma Investments II, L.P.

**Item 2(b). Address of Principal Business Office:**
Redmile Group, LLC
One Letterman Drive
Building D, Suite D3-300
The Presidio of San Francisco
San Francisco, California 94129

Jeremy C. Greenc/o Redmile Group, LLC (NY Office)
45 W. 27th Street, Floor 11
New York, NY 10001

Redmile Biopharma Investments II, L.P.c/o Redmile Group, LLC
One Letterman Drive
Building D, Suite D3-300
The Presidio of San Francisco
San Francisco, California 94129

**Item 2(c). Citizenship:**
Redmile Group, LLC: Delaware
Jeremy C. Green: United Kingdom
Redmile Biopharma Investments II, L.P.: Delaware

**Item 2(d). Title of Class of Securities:**
Common Stock, par value $0.001 per share

**Item 2(e). CUSIP Number:**
03589W102

**Item 3. If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:**

(a) [ ] Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o).

(b) [ ] Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c).

(c) [ ] Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c).

(d) [ ] Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8).

(e) [ ] An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);

(f) [ ] An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);

(g) [ ] A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);

(h) [ ] A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);

(i) [ ] A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);

(j) [ ] A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), if filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:

(k) [ ] Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).

**Item 4. Ownership:**

**(a) Amount beneficially owned:**

Redmile Group, LLC - 15,427,866 (1)
Jeremy C. Green - 15,427,866 (1)
Redmile Biopharma Investments II, L.P. - 7,288,917 (2)

**(b) Percent of class:**

Redmile Group, LLC - 9.9% (3)
Jeremy C. Green - 9.9% (3)
Redmile Biopharma Investments II, L.P. - 4.7% (3)

**(c) Number of shares as to which the person has:**

**(i) Sole power to vote or to direct the vote:**

Redmile Group, LLC - 0
Jeremy C. Green - 0
Redmile Biopharma Investments II, L.P. - 0

**(ii) Shared power to vote or to direct the vote:**

Redmile Group, LLC - 15,427,866 (1)
Jeremy C. Green - 15,427,866 (1)
Redmile Biopharma Investments II, L.P. - 7,288,917 (2)

**(iii) Sole power to dispose or to direct the disposition of:**

Redmile Group, LLC - 0
Jeremy C. Green - 0
Redmile Biopharma Investments II, L.P. - 0

**(iv) Shared power to dispose or to direct the disposition of:**

Redmile Group, LLC - 15,427,866 (1)
Jeremy C. Green - 15,427,866 (1)
Redmile Biopharma Investments II, L.P. - 7,288,917 (2)
(1) Redmile Group, LLC's and Jeremy C. Green's beneficial ownership of the Issuer's Common Stock is comprised of 10,050,644 shares of Common Stock owned by the Redmile Clients, including RBI II. Subject to the Beneficial Ownership Blocker, Redmile Group, LLC and Mr. Green may also be deemed to beneficially own 45,109,195 shares of Common Stock issuable upon exercise of the Warrants. Pursuant to the terms of the Warrants, the Issuer may not effect any exercise of any Warrant, and a holder of a Warrant does not have the right to exercise any portion of the Warrant held by such holder, if the Beneficial Ownership Blocker applies. The 15,427,866 shares of Common Stock reported as beneficially owned by Redmile Group, LLC and Mr. Green in this Schedule 13G represent 9.99% of the outstanding shares of Common Stock (calculated in accordance with footnote (3) below), which represent the shares of Common Stock held directly by the Redmile Clients and the 5,377,222 shares of Common Stock that could be issued upon exercise of certain of the Warrants under the Beneficial Ownership Blocker. The reported securities may be deemed beneficially owned by Redmile Group, LLC as investment manager of the Redmile Clients. The reported securities may also be deemed beneficially owned by Jeremy C. Green as the principal of Redmile Group, LLC. Redmile Group, LLC and Mr. Green each disclaim beneficial ownership of these shares, except to the extent of its or his pecuniary interest in such shares, if any.
(2) RBI II's beneficial ownership of Common Stock is comprised of 1,911,695 shares of Common Stock. Subject to the Beneficial Ownership Blocker, RBI II may also be deemed to beneficially own 6,702,359 shares of Common Stock issuable upon exercise of the Warrants directly held by RBI II. Pursuant to the terms of the Warrants, the Issuer may not effect any exercise of any Warrant, and a holder of a Warrant does not have the right to exercise any portion of the Warrant held by such holder, if the Beneficial Ownership Blocker applies. The shares of Common Stock reported as beneficially owned by RBI II in this Schedule 13G represent the shares of Common Stock held directly by RBI II and the 5,377,222 shares of Common Stock that could be issued to RBI II upon exercise of certain of the Warrants directly held by RBI II under the Beneficial Ownership Blocker.
(3) Percentage based on: (i) 119,632,804 shares of Common Stock outstanding as of November 5, 2025, as reported in the Form 10-Q; plus (ii) 29,423,075 shares of Common Stock issued and sold as of November 14, 2025, as reported in the Form 8-K; plus (iii) 5,377,222 shares of Common Stock issuable upon exercise of the Warrants, which due to the Beneficial Ownership Limitation is the maximum number of shares that could be issued upon exercise of the Warrants.

**Item 5. Ownership of Five Percent or Less of a Class.**

[ ] If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following.

**Item 6. Ownership of More than 5 Percent on Behalf of Another Person.**

Not Applicable

**Item 7. Identification and Classification of the Subsidiary**

See the response to Item 4.

**Item 8. Identification and Classification of Members of the Group**

Not Applicable

**Item 9. Notice of Dissolution of Group**

Not Applicable

**Item 10. Certification:**

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11.

### 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.

**Redmile Group, LLC**

**Date:** 02/17/2026

**By:** /s/ Jeremy C. Green

**Name & Title:** Managing Member

**Jeremy C. Green**

**Date:** 02/17/2026

**By:** /s/ Jeremy C. Green

**Name & Title:** Jeremy C. Green

**Redmile Biopharma Investments II, L.P.**

**Date:** 02/17/2026

**By:** /s/ Jeremy C. Green

**Name & Title:** Managing Member of Redmile Biopharma Investments II (GP), LLC, General Partner of Redmile Biopharma Investments II, L.P.