# EDGAR Filing Document

**Accession Number:** 0001688327
**File Stem:** 0001193125-26-051800
**Filing Date:** 2026-2
**Character Count:** 18269
**Document Hash:** 0e7b9586475e270cb8c0905abbfd59be
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-26-051800.hdr.sgml**: 20260213

**ACCESSION NUMBER**: 0001193125-26-051800

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

**PUBLIC DOCUMENT COUNT**: 1

**FILED AS OF DATE**: 20260213

**DATE AS OF CHANGE**: 20260213

**SUBJECT COMPANY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Maze Therapeutics, Inc.
- **CENTRAL INDEX KEY:** 0001842295
- **STANDARD INDUSTRIAL CLASSIFICATION:** BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 000000000
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13G/A
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 005-94841
- **FILM NUMBER:** 26634729

**BUSINESS ADDRESS:**
- **STREET 1:** 171 OYSTER POINT BOULEVARD, SUITE 300
- **CITY:** SOUTH SAN FRANCISCO
- **STATE:** CA
- **ZIP:** 94080
- **BUSINESS PHONE:** 6508505070

**MAIL ADDRESS:**
- **STREET 1:** 171 OYSTER POINT BOULEVARD, SUITE 300
- **CITY:** SOUTH SAN FRANCISCO
- **STATE:** CA
- **ZIP:** 94080
**FILED BY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Third Rock Ventures IV, L.P.
- **CENTRAL INDEX KEY:** 0001688327

**ORGANIZATION NAME:**
- **EIN:** 000000000
- **STATE OF INCORPORATION:** MA
- **FISCAL YEAR END:** 1231

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

**BUSINESS ADDRESS:**
- **STREET 1:** 201 BROOKLINE AVENUE, 14TH FLOOR
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02215
- **BUSINESS PHONE:** 617-585-2000

**MAIL ADDRESS:**
- **STREET 1:** 201 BROOKLINE AVENUE, 14TH FLOOR
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02215

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

## SCHEDULE 13G

### Under the Securities Exchange Act of 1934

**(Amendment No. 1)**

**Issuer:** Maze Therapeutics, Inc.

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

**CUSIP Number:** 578784100

**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)

- [ ] Rule 13d-1(c)

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

---

| 1. | Names of Reporting Persons<br>Third Rock Ventures IV, L.P. | Names of Reporting Persons<br>Third Rock Ventures IV, L.P. |
|:---|:---|:---|:---|
| 2. | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [x] | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [x] |
| 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 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 6. | Shared Voting Power<br>4473958 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 7. | Sole Dispositive Power<br>0 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 8. | Shared Dispositive Power<br>4473958 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>4473958 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>4473958 |
| 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>9.3% | Percent of Class Represented by Amount in Row (9)<br>9.3% |
| 12. | Type of Reporting Person (See Instructions)<br>PN | Type of Reporting Person (See Instructions)<br>PN |

---

| 1. | Names of Reporting Persons<br>Third Rock Ventures GP IV, L.P. | Names of Reporting Persons<br>Third Rock Ventures GP IV, L.P. |
|:---|:---|:---|:---|
| 2. | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [x] | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [x] |
| 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 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 6. | Shared Voting Power<br>4473958 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 7. | Sole Dispositive Power<br>0 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 8. | Shared Dispositive Power<br>4473958 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>4473958 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>4473958 |
| 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>9.3% | Percent of Class Represented by Amount in Row (9)<br>9.3% |
| 12. | Type of Reporting Person (See Instructions)<br>PN | Type of Reporting Person (See Instructions)<br>PN |

---

| 1. | Names of Reporting Persons<br>TRV GP IV, LLC | Names of Reporting Persons<br>TRV GP IV, LLC |
|:---|:---|:---|:---|
| 2. | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [x] | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [x] |
| 3. | SEC Use Only | SEC Use Only |
| 4. | Citizenship or Place of Organization<br>— | Citizenship or Place of Organization<br>— |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 5. | Sole Voting Power<br>0 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 6. | Shared Voting Power<br>4473958 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 7. | Sole Dispositive Power<br>0 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 8. | Shared Dispositive Power<br>4473958 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>4473958 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>4473958 |
| 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>9.3% | Percent of Class Represented by Amount in Row (9)<br>9.3% |
| 12. | Type of Reporting Person (See Instructions)<br>OO | Type of Reporting Person (See Instructions)<br>OO |

---

| 1. | Names of Reporting Persons<br>Third Rock Ventures V, L.P. | Names of Reporting Persons<br>Third Rock Ventures V, L.P. |
|:---|:---|:---|:---|
| 2. | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [x] | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [x] |
| 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 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 6. | Shared Voting Power<br>950800 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 7. | Sole Dispositive Power<br>0 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 8. | Shared Dispositive Power<br>950800 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>950800 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>950800 |
| 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>2.0% | Percent of Class Represented by Amount in Row (9)<br>2.0% |
| 12. | Type of Reporting Person (See Instructions)<br>PN | Type of Reporting Person (See Instructions)<br>PN |

---

| 1. | Names of Reporting Persons<br>Third Rock Ventures GP V, L.P. | Names of Reporting Persons<br>Third Rock Ventures GP V, L.P. |
|:---|:---|:---|:---|
| 2. | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [x] | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [x] |
| 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 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 6. | Shared Voting Power<br>950800 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 7. | Sole Dispositive Power<br>0 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 8. | Shared Dispositive Power<br>950800 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>950800 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>950800 |
| 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>2.0% | Percent of Class Represented by Amount in Row (9)<br>2.0% |
| 12. | Type of Reporting Person (See Instructions)<br>PN | Type of Reporting Person (See Instructions)<br>PN |

---

| 1. | Names of Reporting Persons<br>TRV GP V, LLC | Names of Reporting Persons<br>TRV GP V, LLC |
|:---|:---|:---|:---|
| 2. | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [x] | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [x] |
| 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 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 6. | Shared Voting Power<br>950800 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 7. | Sole Dispositive Power<br>0 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 8. | Shared Dispositive Power<br>950800 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>950800 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>950800 |
| 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>2.0% | Percent of Class Represented by Amount in Row (9)<br>2.0% |
| 12. | Type of Reporting Person (See Instructions)<br>OO | Type of Reporting Person (See Instructions)<br>OO |

---

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

**Item 1(b). Address of Issuer's Principal Executive Offices:**
171 Oyster Point Boulevard, Suite 300, San Francisco, CA 94939

**Item 2(a). Name of Person Filing:**
(i)  Third Rock Ventures IV, L.P. ("TRV IV");

(ii)  Third Rock Ventures GP IV, L.P. ("TRV GP IV"), which is the sole general partner of TRV IV;

(iii)  TRV GP IV, LLC ("TRV GP IV LLC"), which is the sole general partner of TRV GP IV;

(iv)  Third Rock Ventures V, L.P. ("TRV V");

(v)  Third Rock Ventures GP V, L.P. ("TRV GP V"), which is the sole general partner of TRV V; and

 (vi)  TRV GP V, LLC ("TRV GP V LLC"), which is the sole general partner of TRV GP V.

**Item 2(b). Address of Principal Business Office:**
The address of the principal business office of each of the Reporting Persons is Third Rock Ventures, LLC, 201 Brookline Ave, Suite 1401, Boston, MA 02215.

**Item 2(c). Citizenship:**
Each of TRV IV, TRV GP IV, TRV V and TRV GP V is a Delaware limited partnership. Each of TRV GP IV LLC and TRV GP V LLC is a Delaware limited liability company.

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

**Item 2(e). CUSIP Number:**
578784100

**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:**

(i)   TRV IV directly owns 4,473,958 shares of Common Stock (the "IV Shares")
(ii)  TRV GP IV is the general partner of TRV IV and may be deemed to beneficially own the IV Shares.
(iii) TRV GP IV LLC is the general partner of TRV GP IV and may be deemed to beneficially own the IV Shares.
(iv) TRV V directly owns 950,800 shares of Common Stock (the "V Shares").
(v)  TRV GP V is the general partner of TRV V and may be deemed to beneficially own the V Shares.
(vi) TRV GP V LLC is the general partner of TRV GP V and may be deemed to beneficially own the V Shares.
Each of TRV IV, TRV GP IV, and TRV GP IV LLC, on the one hand, and TRV V, TRV GP V and TRV GP V LLC, on the other hand, disclaim the existence of a "group" for purposes of Rule 13d-5 of the Securities Exchange Act of 1934, as amended, and nothing contained in this report shall be deemed an admission that any such group exists or may exist.

**(b) Percent of class:**

The IV shares represent approximately 9.3% of the outstanding shares of Common Stock.
The V shares represent approximately 2.0% of the outstanding shares of Common Stock.
The percent of class was calculated based on 48,119,440 shares of common stock issued and outstanding as of November 3, 2025, as disclosed in the Issuer's 10-Q filed with the Securities and Exchange Commission on November 6, 2025.

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

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

TRV IV - 0
TRV GP IV - 0
TRV GP IV LLC - 0
TRV V - 0
TRV GP V - 0
TRV GP V LLC - 0

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

TRV IV - 4,473,958 shares
TRV GP IV - 4,473,958 shares
TRV GP IV LLC - 4,473,958 shares
TRV V - 950,800 shares
TRV GP V - 950,800 shares
TRV GP V LLC - 950,800 shares

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

TRV IV - 0
TRV GP IV - 0
TRV GP IV LLC - 0
TRV V  - 0
TRV GP V - 0
TRV GP V LLC - 0

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

TRV IV -  4,473,958 shares
TRV GP IV - 4,473,958 shares
TRV GP IV LLC - 4,473,958 shares
TRV V - 950,800 shares
TRV GP V - 950,800 shares
TRV GP V LLC - 950,800 shares

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

[x] 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**

Not Applicable

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

Not Applicable

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

Not Applicable

**Item 10. Certification:**

—

### 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.

**Third Rock Ventures IV, L.P.**

**Date:** 02/13/2026

**By:** /s/ Kevin Gillis

**Name & Title:** Kevin Gillis, COO of TRV GP IV, LLC, general partner of Third Rock Ventures GP IV, L.P., general partner of Third Rock Ventures IV, L.P.

**Third Rock Ventures GP IV, L.P.**

**Date:** 02/13/2026

**By:** /s/ Kevin Gillis

**Name & Title:** Kevin Gillis, Chief Operating Officer of TRV GP IV, LLC, general partner of Third Rock Ventures GP IV, L.P

**TRV GP IV, LLC**

**Date:** 02/13/2026

**By:** /s/ Kevin Gillis

**Name & Title:** Kevin Gillis, Chief Operating Officer of TRV GP IV, LLC

**Third Rock Ventures V, L.P.**

**Date:** 02/13/2026

**By:** /s/ Kevin Gillis

**Name & Title:** Kevin Gillis, COO of TRV GP V, LLC, general partner of Third Rock Ventures GP V, L.P., general partner of Third Rock Ventures V, L.P.

**Third Rock Ventures GP V, L.P.**

**Date:** 02/13/2026

**By:** /s/ Kevin Gillis

**Name & Title:** Kevin Gillis, Chief Operating Officer of TRV GP V, LLC, general partner of Third Rock Ventures GP V, L.P.

**TRV GP V, LLC**

**Date:** 02/13/2026

**By:** /s/ Kevin Gillis

**Name & Title:** Kevin Gillis, Chief Operating Officer of TRV GP V, LLC