# EDGAR Filing Document

**Accession Number:** 0001707502
**File Stem:** 0001193125-26-100348
**Filing Date:** 2026-3
**Character Count:** 23675
**Document Hash:** e4d88de49ca7747eacb050c8a29d4bb1
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-26-100348.hdr.sgml**: 20260310

**ACCESSION NUMBER**: 0001193125-26-100348

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

**PUBLIC DOCUMENT COUNT**: 2

**FILED AS OF DATE**: 20260310

**DATE AS OF CHANGE**: 20260310

**SUBJECT COMPANY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Solid Biosciences Inc.
- **CENTRAL INDEX KEY:** 0001707502
- **STANDARD INDUSTRIAL CLASSIFICATION:** BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 900943402
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13D/A
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 005-90280
- **FILM NUMBER:** 26740238

**BUSINESS ADDRESS:**
- **STREET 1:** 500 RUTHERFORD AVENUE
- **STREET 2:** 3RD FLOOR
- **CITY:** CHARLESTOWN
- **STATE:** MA
- **ZIP:** 02129
- **BUSINESS PHONE:** 617-337-4680

**MAIL ADDRESS:**
- **STREET 1:** 500 RUTHERFORD AVENUE
- **STREET 2:** 3RD FLOOR
- **CITY:** CHARLESTOWN
- **STATE:** MA
- **ZIP:** 02129

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** Solid Biosciences, LLC
- **DATE OF NAME CHANGE:** 20170524
**FILED BY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** BCLS SB Investco, LP
- **CENTRAL INDEX KEY:** 0001728056

**ORGANIZATION NAME:**
- **EIN:** 820630705
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

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

**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_d-11.pdf`

_No text found in this document._

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

## SCHEDULE 13D

### Under the Securities Exchange Act of 1934

**(Amendment No. 11)**

**Solid Biosciences Inc.**

*(Name of Issuer)*

**Common Stock, $0.001 par value per share**

*(Title of Class of Securities)*

**83422E105**

*(CUSIP Number)*

**Bain Capital Life Sciences Inv**<br>200 Clarendon Street<br>Boston MA 02116<br>617-516-2000

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

**03/06/2026**

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

| **CUSIP No.** | **83422E105** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**BCLS SB Investco, LP** | Name of reporting person<br>**BCLS SB Investco, LP** | |
| 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>**WC** | Source of funds (See Instructions)<br>**WC** | |
| 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>**DELAWARE** | Citizenship or place of organization<br>**DELAWARE** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**0.00** |
| 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>**0.00** |
| 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>**0.00** | Aggregate amount beneficially owned by each reporting person<br>**0.00** | |
| 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>**0%** | Percent of class represented by amount in Row (11)<br>**0%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**PN** | Type of Reporting Person (See Instructions)<br>**PN** | |

---

| **CUSIP No.** | **83422E105** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**Bain Capital Life Sciences Fund II, L.P.** | Name of reporting person<br>**Bain Capital Life Sciences Fund II, L.P.** | |
| 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>**SC** | Source of funds (See Instructions)<br>**SC** | |
| 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>**CAYMAN ISLANDS** | Citizenship or place of organization<br>**CAYMAN ISLANDS** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**267257.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**267257.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**267257.00** | Aggregate amount beneficially owned by each reporting person<br>**267257.00** | |
| 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>**0.3%** | Percent of class represented by amount in Row (11)<br>**0.3%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**PN** | Type of Reporting Person (See Instructions)<br>**PN** | |

---

| **CUSIP No.** | **83422E105** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**BCLS II Investco, LP** | Name of reporting person<br>**BCLS II Investco, LP** | |
| 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>**WC** | Source of funds (See Instructions)<br>**WC** | |
| 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>**DELAWARE** | Citizenship or place of organization<br>**DELAWARE** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**8604852.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**8604852.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**8604852.00** | Aggregate amount beneficially owned by each reporting person<br>**8604852.00** | |
| 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>**8.8%** | Percent of class represented by amount in Row (11)<br>**8.8%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**PN** | Type of Reporting Person (See Instructions)<br>**PN** | |

---

| **CUSIP No.** | **83422E105** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**BCIP Life Sciences Associates, LP** | Name of reporting person<br>**BCIP Life Sciences Associates, LP** | |
| 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>**SC** | Source of funds (See Instructions)<br>**SC** | |
| 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>**DELAWARE** | Citizenship or place of organization<br>**DELAWARE** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**32550.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**32550.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**32550.00** | Aggregate amount beneficially owned by each reporting person<br>**32550.00** | |
| 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>**0.1%** | Percent of class represented by amount in Row (11)<br>**0.1%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**PN** | Type of Reporting Person (See Instructions)<br>**PN** | |

---

| **CUSIP No.** | **83422E105** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**BCLS II Equity Opportunities, LP** | Name of reporting person<br>**BCLS II Equity Opportunities, LP** | |
| 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>**WC** | Source of funds (See Instructions)<br>**WC** | |
| 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>**DELAWARE** | Citizenship or place of organization<br>**DELAWARE** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**904160.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**904160.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**904160.00** | Aggregate amount beneficially owned by each reporting person<br>**904160.00** | |
| 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>**1.0%** | Percent of class represented by amount in Row (11)<br>**1.0%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**PN** | Type of Reporting Person (See Instructions)<br>**PN** | |

---

| **CUSIP No.** | **83422E105** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**Bain Capital Life Sciences Opportunities IV, L.P.** | Name of reporting person<br>**Bain Capital Life Sciences Opportunities IV, L.P.** | |
| 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>**WC** | Source of funds (See Instructions)<br>**WC** | |
| 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>**DELAWARE** | Citizenship or place of organization<br>**DELAWARE** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**5302897.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**5302897.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**5302897.00** | Aggregate amount beneficially owned by each reporting person<br>**5302897.00** | |
| 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>**5.4%** | Percent of class represented by amount in Row (11)<br>**5.4%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**PN** | Type of Reporting Person (See Instructions)<br>**PN** | |

---

**Item 1. Security and Issuer**

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

**(b) Name of Issuer:**
Solid Biosciences Inc.

**(c) Address of Issuer's Principal Executive Offices:**
500 Rutherford Avenue, Third Floor, Charlestown, MA, 02129

This Amendment No. 11 to Schedule 13D relates to the Common Stock of Solid Biosciences Inc. and amends the initial statement on Schedule 13D filed by BCLS SB Investco, LP on February 1, 2018, as amended by Amendment No. 1 filed on July 30, 2019, Amendment No. 2 filed on December 11, 2020, Amendment No. 3 filed on March 25, 2021, Amendment No. 4 filed on August 18, 2022, Amendment No. 5 filed on October 3, 2022, Amendment No. 6 filed on December 5, 2022, Amendment No. 7 filed on January 10, 2024, Amendment No. 8 filed on January 12, 2024, Amendment No. 9 filed on June 11, 2024 and Amendment No. 10 filed on February 21, 2025 (the "Initial Statement" and, as further amended by this Amendment No. 11, the "Schedule 13D"). Capitalized terms used but not defined herein shall have the meanings ascribed to them in the Initial Statement.

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

**(a)**
The information set forth in Items 2, 3 and 6 and on the cover pages of this Schedule 13D is incorporated by reference in its entirety into this Item 5.

As of the date hereof, (i) BCLS SB holds no shares of Common Stock, (ii) BCLS Fund II holds 267,257 shares of Common Stock, (iii) BCLS II Investco holds 3,301,955 shares of Common Stock and a Pre-Funded Warrant to purchase 6,444,170 shares of Common Stock, (iv) BCIPLS holds 32,550 shares of Common Stock, (v) BCLS II Equity holds 904,160 shares of Common Stock and (vi) BCLS Fund IV Opportunities holds a March 2026 Pre-Funded Warrant to purchase 5,347,593 shares of Common Stock. As a result of the Beneficial Ownership Blocker and the March 2026 Beneficial Ownership Blocker, BCLS II Investco and BCLS Fund IV Opportunities are prohibited from exercising the Pre-Funded Warrant and the March 2026 Pre-Funded Warrant to the extent that the Reporting Persons would, after such exercise, collectively beneficially own in excess of 9.99% of the outstanding Common Stock. Accordingly, pursuant to Rule 13d-3 of the Act and the relationships described in Item 2 of this Schedule 13D, the Reporting Persons may be deemed to collectively beneficially own 9.99% of the outstanding Common Stock, representing 9,808,819 shares of Common Stock as of the date hereof.

The calculation of the beneficial ownership of the Reporting Persons is based on (i) 77,910,239 shares of Common Stock issued and outstanding as of October 29, 2025, as disclosed by the Issuer in its quarterly report on Form 10-Q filed with the Securities and Exchange Commission on November 3, 2025, (ii) 14,973,257 shares of Common Stock issued in the March 2026 Private Placement and (iii) 5,302,897 shares of Common Stock to be issued upon the exercise of the Pre-Funded Warrant and/or March 2026 Pre-Funded Warrant held by BCLS II Investco and BCLS Fund IV Opportunities, which reflects the Beneficial Ownership Blocker and the March 2026 Beneficial Ownership Blocker.

**(b)**
See Item 5(a) hereof.

**(c)**
See Item 3 hereof.

**Item 6. Contracts, Arrangements, Understandings or Relationships With Respect to Securities of the Issuer.**

Item 6 of the Initial Statement is hereby amended and supplemented to add the following:

Each March 2026 Pre-Funded Warrant is exercisable at any time after its original issuance. The holder of a March 2026 Pre-Funded Warrant is prohibited from exercising the March 2026 Pre-Funded Warrant into Common Stock if, as a result of such exercise, the holder, together with its affiliates and any other persons whose beneficial ownership would be aggregated with the holder's for purposes of Section 13(d) of the Act, would beneficially own more than 9.99% of the total number of shares of Common Stock issued and outstanding immediately after giving effect to such exercise (the "Beneficial Ownership Blocker"). The exercise price per share of Common Stock purchasable upon the exercise of the March 2026 Pre-Funded Warrant is $0.001 per share. The exercise price is subject to appropriate adjustment in the event of certain stock dividends and distributions, stock splits, stock combinations, or reclassifications affecting the Common Stock. If a Fundamental Transaction (as defined in the March 2026 Pre-Funded Warrant) occurs while a March 2026 Pre-Funded Warrant is outstanding, then upon any subsequent exercise of the March 2026 Pre-Funded Warrant, the holder thereof has the right to receive the same amount and kind of securities, cash or property as such holder would have been entitled to receive upon the occurrence of such Fundamental Transaction if it had been, immediately prior to such Fundamental Transaction, the holder of the number of shares of Common Stock then issuable upon exercise in full of the March 2026 Pre-Funded Warrant (without regard to any limitations on exercise). Subject to compliance with applicable securities laws, each March 2026 Pre-Funded Warrant may be transferred or assigned by the holder thereof without the Issuer's consent. Except as otherwise provided in the March 2026 Pre-Funded Warrant or by virture of the holder's ownership of Common Stock, the holder of a March 2026 Pre-Funded Warrant does not have the rights or privileges of a holder of Common Stock, including any voting rights, until the holder exercises the March 2026 Pre-Funded Warrant. The foregoing summary of the March 2026 Pre-Funded Warrant does not purport to be complete and is qualified in its entirety by reference to the form of March 2026 Pre-Funded Warrant, which is filed as an exhibit hereto and incorporated by reference herein.

On March 6, 2026, the Issuer entered into a registration rights agreement (the "March 2026 Registration Rights Agreement") with the March 2026 PIPE Investors, including BCLS Fund IV Opportunities, pursuant to which the Issuer agreed to register for resale the shares of Common Stock issued in the March 2026 Private Placement and the shares of Common Stock issuable upon exercise of the pre-funded warrants issued in the March 2026 Private Placement (collectively, the "March 2026 Registrable Securities"). Under theMarch 2026 Registration Rights Agreement, the Issuer agreed to file a registration statement covering the resale by the March 2026 PIPE Investors of their March 2026 Registrable Securities no later than 30 days following the closing of the March 2026 Private Placement (the "March 2026 Filing Date"). The Issuer agreed to use commercially reasonable efforts to cause such registration statement to be declared effective as soon as reasonably practicable and to keep such registration statement effective until the date all March 2026 Registrable Securities covered by such registration statement have been sold or cease to be registrable securities under the March 2026 Registration Rights Agreement. The foregoing summary of the March 2026 Registration Rights Agreement does not purport to be complete and is qualified in its entirety by reference to the full text of the March 2026 Registration Rights Agreement, which is filed as an exhibit hereto and incorporated by reference herein.

### 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:** BCLS SB Investco, LP

**Signature:** /s/ Adam Koppel

**Name/Title:** Adam Koppel, Partner of Bain Capital Life Sciences Investors, LLC

**Date:** 03/10/2026

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

**Signature:** /s/ Adam Koppel

**Name/Title:** Adam Koppel, Partner of Bain Capital Life Sciences Investors, LLC

**Date:** 03/10/2026

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:** BCLS II Investco, LP

**Signature:** /s/ Adam Kopppel

**Name/Title:** Adam Koppel, Partner of Bain Capital Life Sciences Investors, LLC

**Date:** 03/10/2026

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:** BCIP Life Sciences Associates, LP

**Signature:** /s/ Adam Koppel

**Name/Title:** Adam Koppel, Authorized Signatory of Boylston Coinvestors, LLC

**Date:** 03/10/2026

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:** BCLS II Equity Opportunities, LP

**Signature:** /s/ Adam Koppel

**Name/Title:** Adam Koppel, Partner of Bain Capital Life Sciences Investors, LLC

**Date:** 03/10/2026

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:** Bain Capital Life Sciences Opportunities IV, L.P.

**Signature:** /s/ Adam Kpppel

**Name/Title:** Adam Koppel, Partner of Bain Capital Life Sciences Investors, LLC

**Date:** 03/10/2026