# EDGAR Filing Document

**Accession Number:** 0001773187
**File Stem:** 0000950130-25-000220
**Filing Date:** 2025-10
**Character Count:** 13858
**Document Hash:** 679e7bd1d5b781ff49cb794eb4b23f0d
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0000950130-25-000220.hdr.sgml**: 20251024

**ACCESSION NUMBER**: 0000950130-25-000220

**CONFORMED SUBMISSION TYPE**: SCHEDULE 13G

**PUBLIC DOCUMENT COUNT**: 2

**FILED AS OF DATE**: 20251024

**DATE AS OF CHANGE**: 20251024

**SUBJECT COMPANY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** C4 Therapeutics, Inc.
- **CENTRAL INDEX KEY:** 0001662579
- **STANDARD INDUSTRIAL CLASSIFICATION:** BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 475617627
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13G
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 005-91763
- **FILM NUMBER:** 251416535

**BUSINESS ADDRESS:**
- **STREET 1:** 490 ARSENAL WAY
- **STREET 2:** SUITE 120
- **CITY:** WATERTOWN
- **STATE:** MA
- **ZIP:** 02472
- **BUSINESS PHONE:** (617) 231-0700

**MAIL ADDRESS:**
- **STREET 1:** 490 ARSENAL WAY
- **STREET 2:** SUITE 120
- **CITY:** WATERTOWN
- **STATE:** MA
- **ZIP:** 02472
**FILED BY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Bain Capital Life Sciences Fund II, L.P.
- **CENTRAL INDEX KEY:** 0001773187

**ORGANIZATION NAME:**
- **EIN:** 000000000
- **STATE OF INCORPORATION:** E9
- **FISCAL YEAR END:** 1231

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

**BUSINESS ADDRESS:**
- **STREET 1:** 200 CLARENDON STREET
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02116
- **BUSINESS PHONE:** 6175162000

**MAIL ADDRESS:**
- **STREET 1:** 200 CLARENDON STREET
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02116

### Attached PDF Documents

**Attachment 1:** `ck0000000000-ex99_a.pdf`

_No text found in this document._

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

## SCHEDULE 13G

### Under the Securities Exchange Act of 1934

**Issuer:** C4 Therapeutics, Inc.

**Title of Class of Securities:** Common Stock, par value $0.0001 per share

**CUSIP Number:** 12529R107

**Date of Event Which Requires Filing of this Statement:** 10/17/2025

**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>Bain Capital Life Sciences Fund II, L.P. | Names of Reporting Persons<br>Bain Capital Life Sciences Fund 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>E9 | Citizenship or Place of Organization<br>E9 |
| 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>991188 |
| 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>991188 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>991188 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>991188 |
| 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>1.07% | Percent of Class Represented by Amount in Row (9)<br>1.07% |
| 12. | Type of Reporting Person (See Instructions)<br>PN | Type of Reporting Person (See Instructions)<br>PN |

---

| 1. | Names of Reporting Persons<br>BCIP Life Sciences Associates, LP | Names of Reporting Persons<br>BCIP Life Sciences Associates, LP |
|:---|:---|:---|:---|
| 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 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 6. | Shared Voting Power<br>120722 |
| 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>120722 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>120722 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>120722 |
| 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>0.13% | Percent of Class Represented by Amount in Row (9)<br>0.13% |
| 12. | Type of Reporting Person (See Instructions)<br>PN | Type of Reporting Person (See Instructions)<br>PN |

---

| 1. | Names of Reporting Persons<br>BCLS II Equity Opportunities, LP | Names of Reporting Persons<br>BCLS II Equity Opportunities, LP |
|:---|:---|:---|:---|
| 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 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 6. | Shared Voting Power<br>6060000 |
| 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>6060000 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>6060000 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>6060000 |
| 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>6.25% | Percent of Class Represented by Amount in Row (9)<br>6.25% |
| 12. | Type of Reporting Person (See Instructions)<br>PN | Type of Reporting Person (See Instructions)<br>PN |

---

**Item 1(a). Name of Issuer:**
C4 Therapeutics, Inc.

**Item 1(b). Address of Issuer's Principal Executive Offices:**
490 Arsenal Way, Suite 120, Watertown, Massachusetts 02472

**Item 2(a). Name of Person Filing:**
This Schedule 13G is being filed jointly by Bain Capital Life Sciences Fund II, L.P., a Cayman Islands exempted limited partnership ("BCLS Fund II"), BCIP Life Sciences Associates, LP, a Delaware limited partnership ("BCIPLS"), and BCLS II Equity Opportunities, LP, a Delaware limited partnership ("BCLS II Equity" and, together with BCLS Fund II and BCIPLS, the "Reporting Persons").

Bain Capital Life Sciences Investors, LLC, a Delaware limited liability company ("BCLSI"), is the manager of Bain Capital Life Sciences Investors II, LLC, a Cayman Islands limited liability company ("BCLSI II"), which is the general partner of BCLS Fund II.

Boylston Coinvestors, LLC, a Delaware limited liability company ("Boylston"), is the general partner of BCIPLS. BCLSI governs the investment strategy and decision-making process with respect to investments held by BCIPLS.

BCLS II Equity Opportunities GP, LLC, a Delaware limited liability company ("BCLS II Equity GP" and, together with the Reporting Persons, BCLSI, BCLSI II and Boylston, the "Bain Capital Life Sciences Entities"), whose manager is BCLS Fund II, is the general partner of BCLS II Equity.

As a result, BCLSI may be deemed to share voting and dispositive power with respect to the securities held by the Reporting Persons.

The Reporting Persons have entered into a Joint Filing Agreement, dated October 24, 2025, pursuant to which the Reporting Persons have agreed to file this Schedule 13G jointly in accordance with the provisions of Rule 13d-1(k)(1) promulgated under the Act.

**Item 2(b). Address of Principal Business Office:**
The principal business address for each of the Bain Capital Life Sciences Entities is 200 Clarendon Street, Boston, Massachusetts 02116.

**Item 2(c). Citizenship:**
See Item 2(a) hereof.

**Item 2(d). Title of Class of Securities:**
Common Stock, par value $0.0001 per share

**Item 2(e). CUSIP Number:**
12529R107

**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:**

As of the date hereof, (i) BCLS Fund II holds 991,188 shares of Common Stock; (ii) BCIPLS holds 120,722 shares of Common Stock; and (iii) BCLS II Equity holds 2,020,000 shares of Common Stock and warrants to purchase an aggregate of 4,040,000 Common Stock.  As a result of the foregoing and the relationships described in Item 2(a), the Reporting Persons may be deemed to collectively beneficially own an aggregate of 7,171,910 shares of Common Stock, representing approximately 7.4% of the outstanding Common Stock. BCLS II Equity is prohibited from exercising the warrants to purchase Common Stock if, as a result of such exercise, the Reporting Persons would beneficially own more than 9.99% of the total number of shares of Common Stock then issued and outstanding immediately after giving effect to the exercise.
The calculation of the beneficial ownership of the Reporting Persons is based on (i) 92,902,083 shares of Common Stock outstanding, as reported by the Issuer in its prospectus supplement filed with the Securities and Exchange Commission on October 16, 2025 and (ii) 4,040,000 shares of Common Stock issuable upon the exercise of warrants held by BCLS II Equity.

**(b) Percent of class:**

See Item 4(a) hereof.

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

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

0

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

See Item 4(a) hereof.

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

0

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

See Item 4(a) hereof.

**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:**

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.

**Bain Capital Life Sciences Fund II, L.P.**

**Date:** 10/24/2025

**By:** /s/ Andrew Hack

**Name & Title:** Andrew Hack, Partner of Bain Capital Life Sciences Investors, LLC

**BCIP Life Sciences Associates, LP**

**Date:** 10/24/2025

**By:** /s/ Andrew Hack

**Name & Title:** Andrew Hack, Authorized Signatory of Boylston Coinvestors, LLC

**BCLS II Equity Opportunities, LP**

**Date:** 10/24/2025

**By:** /s/ Andrew Hack

**Name & Title:** Andrew Hack, Partner of Bain Capital Life Sciences Investors, LLC