# EDGAR Filing Document

**Accession Number:** 0001590750
**File Stem:** 0001104659-25-058580
**Filing Date:** 2025-6
**Character Count:** 11483
**Document Hash:** 0146ec9f71567a169f1be3477e0eb0d6
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001104659-25-058580.hdr.sgml**: 20250611

**ACCESSION NUMBER**: 0001104659-25-058580

**CONFORMED SUBMISSION TYPE**: 4

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20250609

**FILED AS OF DATE**: 20250611

**DATE AS OF CHANGE**: 20250611

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Fairmount Healthcare Fund II L.P.
- **CENTRAL INDEX KEY:** 0001769651

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

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-36483
- **FILM NUMBER:** 251040710

**BUSINESS ADDRESS:**
- **STREET 1:** 200 BARR HARBOR DRIVE
- **STREET 2:** SUITE 400
- **CITY:** WEST CONSHOHOCKEN
- **STATE:** PA
- **ZIP:** 19428
- **BUSINESS PHONE:** (267) 760-4066

**MAIL ADDRESS:**
- **STREET 1:** 200 BARR HARBOR DRIVE
- **STREET 2:** SUITE 400
- **CITY:** WEST CONSHOHOCKEN
- **STATE:** PA
- **ZIP:** 19428
**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Fairmount Healthcare Fund II GP LLC
- **CENTRAL INDEX KEY:** 0001830382

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

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-36483
- **FILM NUMBER:** 251040711

**BUSINESS ADDRESS:**
- **STREET 1:** 200 BARR HARBOR DRIVE
- **STREET 2:** SUITE 400
- **CITY:** WEST CONSHOHOCKEN
- **STATE:** PA
- **ZIP:** 19428
- **BUSINESS PHONE:** 267-760-4066

**MAIL ADDRESS:**
- **STREET 1:** 200 BARR HARBOR DRIVE
- **STREET 2:** SUITE 400
- **CITY:** WEST CONSHOHOCKEN
- **STATE:** PA
- **ZIP:** 19428
**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Fairmount Funds Management LLC
- **CENTRAL INDEX KEY:** 0001802528

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

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-36483
- **FILM NUMBER:** 251040712

**BUSINESS ADDRESS:**
- **STREET 1:** 200 BARR HARBOR DRIVE
- **STREET 2:** SUITE 400
- **CITY:** WEST CONSHOHOCKEN
- **STATE:** PA
- **ZIP:** 19428
- **BUSINESS PHONE:** 267-262-5300

**MAIL ADDRESS:**
- **STREET 1:** 200 BARR HARBOR DRIVE
- **STREET 2:** SUITE 400
- **CITY:** WEST CONSHOHOCKEN
- **STATE:** PA
- **ZIP:** 19428
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Viridian Therapeutics, Inc.\DE
- **CENTRAL INDEX KEY:** 0001590750
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 471187261
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **STREET 1:** 221 CRESCENT STREET
- **STREET 2:** SUITE 103A
- **CITY:** WALTHAM
- **STATE:** MA
- **ZIP:** 02453
- **BUSINESS PHONE:** 617.272.4600

**MAIL ADDRESS:**
- **STREET 1:** 221 CRESCENT STREET
- **STREET 2:** SUITE 103A
- **CITY:** WALTHAM
- **STATE:** MA
- **ZIP:** 02453

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** MIRAGEN THERAPEUTICS, INC.
- **DATE OF NAME CHANGE:** 20170213

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** MIRAGEN THERAPEUTICS, INC.
- **DATE OF NAME CHANGE:** 20170213

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** SIGNAL GENETICS, INC.
- **DATE OF NAME CHANGE:** 20140710

### 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).

[ ] 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>Fairmount Funds Management LLC<br><sub>(Last) (First) (Middle)</sub><br>200 BARR HARBOR DRIVE, SUITE 400<br><sub>(Street)</sub><br>WEST CONSHOHOCKEN, PA 19428<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2025-06-09 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [X] 10% Owner<br>[ ] Officer (give title below) [ ] Other (specify below)<br>_ _ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Viridian Therapeutics, Inc.\DE [ VRDN ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[ ] Form filed by One Reporting Person<br>[X] Form filed by More than One Reporting Person |

---

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>Fairmount Healthcare Fund II GP LLC<br><sub>(Last) (First) (Middle)</sub><br>200 BARR HARBOR DRIVE, SUITE 400<br><sub>(Street)</sub><br>WEST CONSHOHOCKEN, PA 19428<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2025-06-09 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [X] 10% Owner<br>[ ] Officer (give title below) [ ] Other (specify below)<br>_ _ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Viridian Therapeutics, Inc.\DE [ VRDN ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[ ] Form filed by One Reporting Person<br>[X] Form filed by More than One Reporting Person |

---

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>Fairmount Healthcare Fund II L.P.<br><sub>(Last) (First) (Middle)</sub><br>200 BARR HARBOR DRIVE, SUITE 400<br><sub>(Street)</sub><br>WEST CONSHOHOCKEN, PA 19428<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2025-06-09 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [X] 10% Owner<br>[ ] Officer (give title below) [ ] Other (specify below)<br>_ _ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Viridian Therapeutics, Inc.\DE [ VRDN ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[ ] Form filed by One Reporting Person<br>[X] 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 | 2025-06-09 |  | M |  | 1600 | A | $7.80 | 3447413 | I | Fairmount Healthcare Fund II LP<sup>(1)</sup> |
| Common Stock | 2025-06-10 |  | M |  | 12500 | A | $12.31 | 3459913 | I | Fairmount Healthcare Fund II LP<sup>(1)</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 |
| Stock Option (Right to Buy) | $7.80 | 2025-06-09 |  | M |  |  | 1600 | <sup>(2)</sup> | 2025-06-10 | Common Stock | 1600 | $0 | 0 | I<sup>(3)</sup> | By: Peter Harwin |
| Stock Option (Right to Buy) | $12.31 | 2025-06-10 |  | M |  |  | 12500 | 2023-06-08 | 2025-06-10 | Common Stock | 12500 | $0 | 0 | I<sup>(3)</sup> | By: Peter Harwin |

---

### Footnotes:

(1) Fairmount Funds Management LLC ("Fairmount") and Fairmount Healthcare Fund II GP LLC ("Fairmount GP II") have voting power and investment power over the securities held by Fairmount Healthcare Fund II LP ("Fund II"). They disclaim beneficial ownership of securities held by Fund II for purposes of Rule 16a-1(a)(2), except to the extent of their pecuniary interest therein.

(2) Beginning on October 27, 2020, the option vested monthly over a three-year period, subject to Peter Harwin's continued service to the Issuer. Mr. Harwin, a Managing Member of Fairmount and Fairmount GP II, served on the Issuer's Board of Directors through March 10, 2025.

(3) Under Mr. Harwin's arrangement with Fairmount, Mr. Harwin held options received as director compensation from the Issuer for one or more investment vehicles managed by Fairmount (each, a "Fairmount Fund"). Mr. Harwin is obligated to turn over to Fairmount any net cash or stock received from such options for the benefit of such Fairmount Fund. Mr. Harwin therefore disclaims beneficial ownership of the option and underlying common stock. Fairmount disclaims beneficial ownership of any of the reported securities, except to the extent of its pecuniary interest therein.

**Remarks:**
The Reporting Persons may each be deemed a director by deputization of Issuer by virtue of the fact that Tomas Kiselak serves on the board of directors of Issuer and is also a Managing Member of Fairmount Funds Management LLC.

**Signature:** /s/ Peter Harwin, Managing Member of Fairmount Funds Management LLC  
**Date:** 2025-06-11

**Signature:** /s/ Peter Harwin, Managing Member of Fairmount Healthcare Fund II GP LLC  
**Date:** 2025-06-11

**Signature:** /s/ Peter Harwin, Managing Member of Fairmount Healthcare Fund II L.P  
**Date:** 2025-06-11

### 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.**