# EDGAR Filing Document

**Accession Number:** 0001823682
**File Stem:** 0001193125-26-102469
**Filing Date:** 2026-3
**Character Count:** 8916
**Document Hash:** 8d6f12b06a6f21fbf86ac263f0408763
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-26-102469.hdr.sgml**: 20260311

**ACCESSION NUMBER**: 0001193125-26-102469

**CONFORMED SUBMISSION TYPE**: 4

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20260309

**FILED AS OF DATE**: 20260311

**DATE AS OF CHANGE**: 20260311

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Kersten Dirk
- **CENTRAL INDEX KEY:** 0001823682

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-39509
- **FILM NUMBER:** 26744592

**MAIL ADDRESS:**
- **STREET 1:** C/O FORBION CAPITAL FUND IV COOPERATIEF
- **STREET 2:** GOOMIER 2-35
- **CITY:** NAARDEN
- **STATE:** P7
- **ZIP:** 14111 DC
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Dyne Therapeutics, Inc.
- **CENTRAL INDEX KEY:** 0001818794
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 364883909
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **STREET 1:** 1560 TRAPELO ROAD
- **CITY:** WALTHAM
- **STATE:** MA
- **ZIP:** 02451
- **BUSINESS PHONE:** (781) 786-8230

**MAIL ADDRESS:**
- **STREET 1:** 1560 TRAPELO ROAD
- **CITY:** WALTHAM
- **STATE:** MA
- **ZIP:** 02451

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

## FORM 4

### STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

[ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

[x] Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>Kersten Dirk<br><sub>(Last) (First) (Middle)</sub><br>C/O DYNE THERAPEUTICS, INC.<br>1560 TRAPELO ROAD<br><sub>(Street)</sub><br>WALTHAM, MA 02451<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2026-03-09 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [ ] 10% Owner<br>[ ] Officer (give title below) [ ] Other (specify below)<br>_ _ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Dyne Therapeutics, Inc. [ DYN ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[X] Form filed by One Reporting Person<br>[ ] Form filed by More than One Reporting Person |

---

## Table I - Non-Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | 3. Transaction Code (V) | 3. Transaction Code (V) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | Code | V | Amount | (A) or (D) | Price | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| Common Stock | 2026-03-09 |  | S<sup>(1)</sup> |  | 177690 | D | 17.7218<sup>(2)</sup> | 5285156 | I | See footnote<sup>(3)(4)</sup> |
| Common Stock | 2026-03-10 |  | S<sup>(1)</sup> |  | 9482 | D | 18.2121<sup>(5)</sup> | 5275674 | I | See footnote<sup>(3)(4)</sup> |
| Common Stock | 2026-03-10 |  | S<sup>(1)</sup> |  | 219758 | D | 19.3250<sup>(6)</sup> | 5055916 | I | See footnote<sup>(3)(4)</sup> |
| Common Stock | 2026-03-10 |  | S<sup>(1)</sup> |  | 281858 | D | 19.8001<sup>(7)</sup> | 4774058 | I | See footnote<sup>(3)(4)</sup> |

---

## Table II - Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | 4. Transaction Code (V) | 4. Transaction Code (V) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 6. Date Exercisable and Expiration Date | 6. Date Exercisable and Expiration Date | 7. Title and Amount of Underlying Securities | 7. Title and Amount of Underlying Securities | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | Code | V | (A) | (D) | Date Exercisable | Expiration Date | Title | Amount or Number of Shares | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |

---

### Footnotes:

(1) This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by ForDyne B.V. ("ForDyne") on November 11, 2025.

(2) The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices within the range of $17.50 to $18.21, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range(s) set forth in the footnotes of this Form 4.

(3) The shares are held directly by ForDyne. ForDyne is jointly owned by Forbion Capital Fund IV Cooperatief U.A. ("FCF IV") and Forbion Growth Opportunities Fund II Cooperatief U.A. ("FGO II"). Forbion IV Management B.V. ("Forbion Management") may be deemed to have voting and dispositive power over 3,347,688 of the shares of common stock held by ForDyne. Investment decisions with respect to the shares held by ForDyne can be made by FCPM III Services B.V., the director of Forbion Management, which may delegate such powers to its investment committee which may delegate such powers to the authorized representatives of Forbion Management. Messrs. Slootweg, van Osch, Mulder, van Houten, Reithinger and Boorsma (the "Partners") are partners of FCPM III Services B.V., which acts as the investment advisor to the directors of ForDyne. The Reporting Person is a partner of Forbion Management and a member of the investment committee of Forbion Management.

(4) (Continued from Footnote 2) Forbion Growth II Management B.V. ("FGO II Management"), the director of FGO II, may be deemed to have voting and dispositive power over 1,426,370 of the shares of common stock held by ForDyne. Investment decisions with respect to the shares held by ForDyne can be made by FCPM III Services B.V., the director of FGO II Management, which may delegate such powers to its investment committee which may delegate such powers to the authorized representatives of FGO II Management. The Partners are partners of FCPM III Services B.V., which acts as the investment advisor to the directors of ForDyne. The Reporting Person is a partner of FGO II Management and a member of the investment committee of FGO II Management. The Reporting Person disclaims beneficial ownership of the shares, except to the extent of his pecuniary interest therein.

(5) The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices within the range of $17.595 to $18.59, inclusive.

(6) The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices within the range of $18.61 to $19.605, inclusive.

(7) The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices within the range of $19.61 to $20.03, inclusive.

**Signature:** /s/ Dirk Kersten  
**Date:** 2026-03-11

### Remarks:

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

**Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.**