# EDGAR Filing Document

**Accession Number:** 0001591747
**File Stem:** 0001104659-25-121740
**Filing Date:** 2025-12
**Character Count:** 10928
**Document Hash:** 5148b8f7bcb52abd136334495641c97e
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001104659-25-121740.hdr.sgml**: 20251216

**ACCESSION NUMBER**: 0001104659-25-121740

**CONFORMED SUBMISSION TYPE**: 4

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20251212

**FILED AS OF DATE**: 20251216

**DATE AS OF CHANGE**: 20251216

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Bitterman Kevin
- **CENTRAL INDEX KEY:** 0001591747

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-39438
- **FILM NUMBER:** 251577086

**MAIL ADDRESS:**
- **STREET 1:** C/O POLARIS VENTURE PARTNERS
- **STREET 2:** 1000 WINTER STREET, SUITE 3350
- **CITY:** WALTHAM
- **STATE:** MA
- **ZIP:** 02451
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Disc Medicine, Inc.
- **CENTRAL INDEX KEY:** 0001816736
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 851612845
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **STREET 1:** 321 ARSENAL STREET, SUITE 101
- **CITY:** WATERTOWN
- **STATE:** MA
- **ZIP:** 02472
- **BUSINESS PHONE:** (617) 674-9274

**MAIL ADDRESS:**
- **STREET 1:** 321 ARSENAL STREET, SUITE 101
- **CITY:** WATERTOWN
- **STATE:** MA
- **ZIP:** 02472

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** Gemini Therapeutics, Inc. /DE
- **DATE OF NAME CHANGE:** 20210209

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** FS Development Corp.
- **DATE OF NAME CHANGE:** 20200702

### 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>Bitterman Kevin<br><sub>(Last) (First) (Middle)</sub><br>C/O DISC MEDICINE, INC.<br>321 ARSENAL STREET, SUITE 101<br><sub>(Street)</sub><br>WATERTOWN, MA 02472<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2025-12-12 | **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>Disc Medicine, Inc. [ IRON ] | **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 | 2025-12-12 |  | S |  | 16403 | D | 92.05<sup>(1)</sup> | 425633 | I | See footnote<sup>(2)</sup> |
| Common Stock | 2025-12-12 |  | S |  | 3852 | D | 92.58<sup>(3)</sup> | 421781 | I | See footnote<sup>(2)</sup> |
| Common Stock | 2025-12-12 |  | S |  | 3446 | D | 93.80<sup>(4)</sup> | 418335 | I | See footnote<sup>(2)</sup> |
| Common Stock | 2025-12-12 |  | S |  | 8527 | D | 92.05<sup>(1)</sup> | 377022 | I | See footnote<sup>(5)</sup> |
| Common Stock | 2025-12-12 |  | S |  | 2005 | D | 92.58<sup>(3)</sup> | 375017 | I | See footnote<sup>(5)</sup> |
| Common Stock | 2025-12-12 |  | S |  | 1793 | D | 93.80<sup>(4)</sup> | 373224 | I | See footnote<sup>(5)</sup> |
| Common Stock | 2025-12-12 |  | S |  | 6570 | D | 92.05<sup>(1)</sup> | 44430 | I | See footnote<sup>(6)</sup> |
| Common Stock | 2025-12-12 |  | S |  | 1540 | D | 92.58<sup>(3)</sup> | 42890 | I | See footnote<sup>(6)</sup> |
| Common Stock | 2025-12-12 |  | S |  | 1371 | D | 93.80<sup>(4)</sup> | 41519 | I | See footnote<sup>(6)</sup> |
| Common Stock | 2025-12-15 |  | S |  | 28913 | D | 91.18<sup>(7)</sup> | 389422 | I | See footnote<sup>(2)</sup> |
| Common Stock | 2025-12-15 |  | S |  | 3921 | D | 92.01<sup>(8)</sup> | 385501 | I | See footnote<sup>(2)</sup> |
| Common Stock | 2025-12-15 |  | S |  | 14811 | D | 91.18<sup>(7)</sup> | 358413 | I | See footnote<sup>(5)</sup> |
| Common Stock | 2025-12-15 |  | S |  | 2049 | D | 92.01<sup>(8)</sup> | 356364 | I | See footnote<sup>(5)</sup> |
| Common Stock | 2025-12-15 |  | S |  | 11427 | D | 91.18<sup>(7)</sup> | 30092 | I | See footnote<sup>(6)</sup> |
| Common Stock | 2025-12-15 |  | S |  | 1572 | D | 92.01<sup>(8)</sup> | 28520 | I | See footnote<sup>(6)</sup> |
| Common Stock | 2025-12-15 |  | M |  | 7000 | A | $13.5 | 7000 | D |  |
| Common Stock | 2025-12-15 |  | S |  | 7000 | D | 91.87<sup>(9)</sup> | 0 | D |  |
| Common Stock | 2025-12-16 |  | S |  | 35898 | D | 91.24<sup>(10)</sup> | 349603 | I | See footnote<sup>(2)</sup> |
| Common Stock | 2025-12-16 |  | S |  | 18666 | D | 91.24<sup>(10)</sup> | 337698 | I | See footnote<sup>(5)</sup> |
| Common Stock | 2025-12-16 |  | S |  | 14359 | D | 91.24<sup>(10)</sup> | 14161 | I | See footnote<sup>(6)</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) | $13.5 | 2025-12-15 |  | M |  |  | 7000 | <sup>(11)</sup> | 2032-12-28 | Common Stock | 7000 | $0 | 0 | D |  |

---

### Footnotes:

(1) The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $91.5289 to $92.4325 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 ranges set forth in footnotes (1), (3), (4), (7), (8), (9) and (10).

(2) These shares are held by Atlas Venture Opportunity Fund I, LP ("Opportunity I"). The general partner of Opportunity I is Atlas Venture Associates Opportunity I, LP ("Associates I"). Atlas Venture Associates Opportunity I, LLC ("Associates I LLC") is the general partner of Associates I. The Reporting Person is a member of Associates I LLC and disclaims beneficial ownership of such securities held by Opportunity I, except to the extent of his pecuniary interest therein, if any.

(3) The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $92.52 to $93.3796 inclusive.

(4) The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $93.52 to $94.255 inclusive.

(5) These shares are held by Atlas Venture Opportunity Fund II, LP ("Opportunity II"). The general partner of Opportunity II is Atlas Venture Associates Opportunity II, LP ("Associates II"). Atlas Venture Associates Opportunity II, LLC ("Associates II LLC") is the general partner of Associates II. The Reporting Person is a member of Associates II LLC and disclaims beneficial ownership of such securities held by Opportunity II, except to the extent of his pecuniary interest therein, if any.

(6) These shares are held by Atlas Venture Fund XII, L.P. ("Atlas XII"). The general partner of Atlas XII is Atlas Venture Associates XII, L.P. ("Associates XII"). Atlas Venture Associates XII, LLC ("Associates XII LLC") is the general partner of Associates XII. The Reporting Person is a member of Associates XII LLC and disclaims beneficial ownership of such securities held by Atlas XII, except to the extent of his pecuniary interest therein, if any.

(7) The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $91.00 to $91.99 inclusive.

(8) The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $92.00 to $92.48 inclusive.

(9) The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $91.79 to $91.95 inclusive.

(10) The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $91.00 to $91.705 inclusive.

(11) Fully Vested.

**Signature:** /s/ Ommer Chohan, Attorney-in-Fact  
**Date:** 2025-12-16

### 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.**