# EDGAR Filing Document

**Accession Number:** 0001352546
**File Stem:** 0001193805-25-001155
**Filing Date:** 2025-8
**Character Count:** 25484
**Document Hash:** 0688c283dd719a01de5c8b03a3879ff3
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193805-25-001155.hdr.sgml**: 20250804

**ACCESSION NUMBER**: 0001193805-25-001155

**CONFORMED SUBMISSION TYPE**: 4

**PUBLIC DOCUMENT COUNT**: 2

**CONFORMED PERIOD OF REPORT**: 20250731

**FILED AS OF DATE**: 20250804

**DATE AS OF CHANGE**: 20250804

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** DEERFIELD MANAGEMENT COMPANY, L.P.
- **CENTRAL INDEX KEY:** 0001009258

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

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-36510
- **FILM NUMBER:** 251182076

**BUSINESS ADDRESS:**
- **STREET 1:** 345 PARK AVENUE SOUTH, 12TH FLOOR
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10010
- **BUSINESS PHONE:** 2125511600

**MAIL ADDRESS:**
- **STREET 1:** 345 PARK AVENUE SOUTH, 12TH FLOOR
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10010

**FORMER NAME:**
- **FORMER CONFORMED NAME:** DEERFIELD MANAGEMENT COMPANY, L.P. (SERIES C)
- **DATE OF NAME CHANGE:** 20180109

**FORMER NAME:**
- **FORMER CONFORMED NAME:** DEERFIELD MANAGEMENT CO
- **DATE OF NAME CHANGE:** 20131114

**FORMER NAME:**
- **FORMER CONFORMED NAME:** DEERFIELD MANAGEMENT CO /NY
- **DATE OF NAME CHANGE:** 19981022
**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Deerfield Mgmt L.P.
- **CENTRAL INDEX KEY:** 0001010823

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-36510
- **FILM NUMBER:** 251182072

**BUSINESS ADDRESS:**
- **STREET 1:** 780 THIRD AVENUE
- **STREET 2:** 37TH FLOOR
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10017
- **BUSINESS PHONE:** 2125511600

**MAIL ADDRESS:**
- **STREET 1:** 780 THIRD AVENUE
- **STREET 2:** 37TH FLOOR
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10017

**FORMER NAME:**
- **FORMER CONFORMED NAME:** DEERFIELD CAPITAL LP
- **DATE OF NAME CHANGE:** 20050930

**FORMER NAME:**
- **FORMER CONFORMED NAME:** DEERFIELD CAPITAL LP ET AL
- **DATE OF NAME CHANGE:** 19960318
**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** DEERFIELD PARTNERS, L.P.
- **CENTRAL INDEX KEY:** 0001301041

**ORGANIZATION NAME:**
- **STATE OF INCORPORATION:** DE

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-36510
- **FILM NUMBER:** 251182068

**BUSINESS ADDRESS:**
- **STREET 1:** 345 PARK AVENUE SOUTH
- **STREET 2:** 12TH FLOOR
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10010
- **BUSINESS PHONE:** 212-551-1600

**MAIL ADDRESS:**
- **STREET 1:** 345 PARK AVENUE SOUTH
- **STREET 2:** 12TH FLOOR
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10010

**FORMER NAME:**
- **FORMER CONFORMED NAME:** DEERFIELD PARTNERS, LP
- **DATE OF NAME CHANGE:** 20040819
**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Flynn James E
- **CENTRAL INDEX KEY:** 0001352546

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-36510
- **FILM NUMBER:** 251182077

**MAIL ADDRESS:**
- **STREET 1:** 780 THIRD AVENUE
- **STREET 2:** 37TH FLOOR
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10017
**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Deerfield Private Design Fund III, L.P.
- **CENTRAL INDEX KEY:** 0001603333

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

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-36510
- **FILM NUMBER:** 251182071

**BUSINESS ADDRESS:**
- **STREET 1:** 780 THIRD AVENUE, 37TH FLOOR
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10017
- **BUSINESS PHONE:** 212-551-1600

**MAIL ADDRESS:**
- **STREET 1:** 780 THIRD AVENUE, 37TH FLOOR
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10017
**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Deerfield Mgmt IV, L.P.
- **CENTRAL INDEX KEY:** 0001713467

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

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-36510
- **FILM NUMBER:** 251182073

**BUSINESS ADDRESS:**
- **STREET 1:** 780 THIRD AVENUE, 37TH FLOOR
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10017
- **BUSINESS PHONE:** 212-551-1600

**MAIL ADDRESS:**
- **STREET 1:** 780 THIRD AVENUE, 37TH FLOOR
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10017
**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Deerfield Mgmt III, L.P.
- **CENTRAL INDEX KEY:** 0001610540

**ORGANIZATION NAME:**
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1214

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-36510
- **FILM NUMBER:** 251182075

**BUSINESS ADDRESS:**
- **STREET 1:** 780 THIRD AVENUE, 37TH FLOOR
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10017
- **BUSINESS PHONE:** 212-551-1600

**MAIL ADDRESS:**
- **STREET 1:** 780 THIRD AVENUE, 37TH FLOOR
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10017
**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Deerfield Healthcare Innovations Fund, L.P.
- **CENTRAL INDEX KEY:** 0001646981

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

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-36510
- **FILM NUMBER:** 251182070

**BUSINESS ADDRESS:**
- **STREET 1:** 780 THIRD AVENUE
- **STREET 2:** 37TH FLOOR
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10017
- **BUSINESS PHONE:** 212-551-1600

**MAIL ADDRESS:**
- **STREET 1:** 780 THIRD AVENUE
- **STREET 2:** 37TH FLOOR
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10017
**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Deerfield Mgmt HIF, L.P.
- **CENTRAL INDEX KEY:** 0001665736

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

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-36510
- **FILM NUMBER:** 251182074

**BUSINESS ADDRESS:**
- **STREET 1:** 780 THIRD AVENUE
- **STREET 2:** 37TH FLOOR
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10017
- **BUSINESS PHONE:** 212-551-1600

**MAIL ADDRESS:**
- **STREET 1:** 780 THIRD AVENUE
- **STREET 2:** 37TH FLOOR
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10017

**FORMER NAME:**
- **FORMER CONFORMED NAME:** Deerfield Mgmt HIF, L.P
- **DATE OF NAME CHANGE:** 20160202
**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Deerfield Private Design Fund IV, L.P.
- **CENTRAL INDEX KEY:** 0001680307

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

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-36510
- **FILM NUMBER:** 251182069

**BUSINESS ADDRESS:**
- **STREET 1:** 780 THIRD AVENUE 37TH FLOOR
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10017
- **BUSINESS PHONE:** (212)551-1600

**MAIL ADDRESS:**
- **STREET 1:** 780 THIRD AVENUE 37TH FLOOR
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10017
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Larimar Therapeutics, Inc.
- **CENTRAL INDEX KEY:** 0001374690
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 203857670
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **STREET 1:** THREE BALA PLAZA EAST. SUITE 506
- **CITY:** BALA CYNWYD
- **STATE:** PA
- **ZIP:** 19004
- **BUSINESS PHONE:** 844-511-9056

**MAIL ADDRESS:**
- **STREET 1:** THREE BALA PLAZA EAST. SUITE 506
- **CITY:** BALA CYNWYD
- **STATE:** PA
- **ZIP:** 19004

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** ZAFGEN, INC.
- **DATE OF NAME CHANGE:** 20100301

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** ZAFGEN INC
- **DATE OF NAME CHANGE:** 20060906

## Ex-99

Joint Filer Information

---

| | |
|:---|:---|
| Names: | Deerfield Management Company, L.P., Deerfield Private Design Fund III, L.P., Deerfield Mgmt III, L.P., Deerfield Healthcare Innovations Fund, L.P., Deerfield Mgmt HIF, L.P., Deerfield Private Design Fund IV, L.P., Deerfield Mgmt IV, L.P., Deerfield Partners, L.P. and Deerfield Mgmt, L.P. |
| Address: | 345 Park Avenue South, 12<sup>th</sup> Floor<br> New York, NY 10010 |
| Designated Filer: | James E. Flynn |
| Issuer and Ticker Symbol: | Larimar Therapeutics, Inc. [LRMR] |
| Date of Event Requiring Statement: | July 31, 2025 |

---

The undersigned, Deerfield Management Company, L.P., Deerfield Private Design Fund III, L.P., Deerfield Mgmt III, L.P., Deerfield Healthcare Innovations Fund, L.P., Deerfield Mgmt HIF, L.P., Deerfield Private Design Fund IV, L.P., Deerfield Mgmt IV, L.P., Deerfield Partners, L.P. and Deerfield Mgmt, L.P. are jointly filing the attached Statement of Changes in Beneficial Ownership on Form 4 with James E. Flynn with respect to the beneficial ownership of securities of Larimar Therapeutics, Inc.

Signatures:

---

| | |
|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp; DEERFIELD MANAGEMENT COMPANY, L.P.<br>By: Deerfield UGP, LLC, General Partner<br>By: <u>/s/ Jonathan Isler</u><br> Jonathan Isler, Attorney-In-Fact | &nbsp;&nbsp;&nbsp;&nbsp; DEERFIELD PRIVATE DESIGN FUND III, L.P.<br>By: Deerfield Mgmt III, L.P., General Partner<br> By Deerfield UGP, LLC, General Partner<br>By: <u>/s/ Jonathan Isler</u><br> Jonathan Isler, Attorney-In-Fact<br>|
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; DEERFIELD MGMT III, L.P.<br>By Deerfield UGP, LLC, General Partner<br>By: <u>/s/ Jonathan Isler</u><br> Jonathan Isler, Attorney-In-Fact<br>| &nbsp;&nbsp;&nbsp;&nbsp; DEERFIELD HEALTHCARE INNOVATIONS FUND, L.P.<br>By: Deerfield Mgmt HIF, L.P., General Partner<br> By: Deerfield UGP, LLC, General Partner<br>By: <u>/s/ Jonathan Isler</u><br> Jonathan Isler, Attorney-In-Fact<br>|
| &nbsp;&nbsp;&nbsp;&nbsp; DEERFIELD MGMT HIF, L.P.<br>By: Deerfield UGP, LLC, General Partner<br>By: <u>/s/ Jonathan Isler</u><br> Jonathan Isler, Attorney-In-Fact | &nbsp;&nbsp;&nbsp;&nbsp; DEERFIELD PRIVATE DESIGN FUND IV, L.P.<br>By: Deerfield Mgmt IV, L.P., General Partner<br> By: Deerfield UGP, LLC, General Partner<br>By: <u>/s/ Jonathan Isler</u><br> Jonathan Isler, Attorney-In-Fact<br>|
| &nbsp;&nbsp;&nbsp;&nbsp; DEERFIELD MGMT IV, L.P.<br>By Deerfield UGP, LLC, General Partner<br>By: <u>/s/ Jonathan Isler</u><br> Jonathan Isler, Attorney-In-Fact | &nbsp;&nbsp;&nbsp;&nbsp; DEERFIELD PARTNERS, L.P.<br>By: Deerfield Mgmt, L.P., General Partner<br> By: Deerfield UGP, LLC, General Partner<br>By: <u>/s/ Jonathan Isler</u><br> Jonathan Isler, Attorney-In-Fact<br>|
| &nbsp;&nbsp;&nbsp;&nbsp; DEERFIELD MGMT, L.P.<br>By: Deerfield UGP, LLC, General Partner<br>By: <u>/s/ Jonathan Isler</u><br> Jonathan Isler, Attorney-In-Fact |  |

---

### 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>Flynn James E<br><sub>(Last) (First) (Middle)</sub><br>345 PARK AVENUE SOUTH, 12TH FLOOR<br><sub>(Street)</sub><br>NEW YORK, NY 10010<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2025-07-31 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [X] 10% Owner<br>[ ] Officer (give title below) [X] Other (specify below)<br>_* Director by Deputization_ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Larimar Therapeutics, Inc. [ LRMR ] | **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>DEERFIELD MANAGEMENT COMPANY, L.P.<br><sub>(Last) (First) (Middle)</sub><br>345 PARK AVENUE SOUTH, 12TH FLOOR<br><sub>(Street)</sub><br>NEW YORK, NY 10010<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2025-07-31 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [X] 10% Owner<br>[ ] Officer (give title below) [X] Other (specify below)<br>_* Director by Deputization_ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Larimar Therapeutics, Inc. [ LRMR ] | **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>Deerfield Mgmt III, L.P.<br><sub>(Last) (First) (Middle)</sub><br>345 PARK AVENUE SOUTH, 12TH FLOOR<br><sub>(Street)</sub><br>NEW YORK, NY 10010<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2025-07-31 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [X] 10% Owner<br>[ ] Officer (give title below) [X] Other (specify below)<br>_* Director by Deputization_ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Larimar Therapeutics, Inc. [ LRMR ] | **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>Deerfield Mgmt HIF, L.P.<br><sub>(Last) (First) (Middle)</sub><br>345 PARK AVENUE SOUTH, 12TH FLOOR<br><sub>(Street)</sub><br>NEW YORK, NY 10010<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2025-07-31 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [X] 10% Owner<br>[ ] Officer (give title below) [X] Other (specify below)<br>_* Director by Deputization_ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Larimar Therapeutics, Inc. [ LRMR ] | **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>Deerfield Mgmt IV, L.P.<br><sub>(Last) (First) (Middle)</sub><br>345 PARK AVENUE SOUTH, 12TH FLOOR<br><sub>(Street)</sub><br>NEW YORK, NY 10010<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2025-07-31 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [X] 10% Owner<br>[ ] Officer (give title below) [X] Other (specify below)<br>_* Director by Deputization_ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Larimar Therapeutics, Inc. [ LRMR ] | **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>Deerfield Mgmt L.P.<br><sub>(Last) (First) (Middle)</sub><br>345 PARK AVENUE SOUTH, 12TH FLOOR<br><sub>(Street)</sub><br>NEW YORK, NY 10010<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2025-07-31 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [X] 10% Owner<br>[ ] Officer (give title below) [X] Other (specify below)<br>_* Director by Deputization_ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Larimar Therapeutics, Inc. [ LRMR ] | **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>Deerfield Private Design Fund III, L.P.<br><sub>(Last) (First) (Middle)</sub><br>345 PARK AVENUE SOUTH, 12TH FLOOR<br><sub>(Street)</sub><br>NEW YORK, NY 10010<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2025-07-31 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [X] 10% Owner<br>[ ] Officer (give title below) [X] Other (specify below)<br>_* Director by Deputization_ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Larimar Therapeutics, Inc. [ LRMR ] | **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>Deerfield Healthcare Innovations Fund, L.P.<br><sub>(Last) (First) (Middle)</sub><br>345 PARK AVENUE SOUTH, 12TH FLOOR<br><sub>(Street)</sub><br>NEW YORK, NY 10010<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2025-07-31 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [X] 10% Owner<br>[ ] Officer (give title below) [X] Other (specify below)<br>_* Director by Deputization_ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Larimar Therapeutics, Inc. [ LRMR ] | **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>Deerfield Private Design Fund IV, L.P.<br><sub>(Last) (First) (Middle)</sub><br>345 PARK AVENUE SOUTH, 12TH FLOOR<br><sub>(Street)</sub><br>NEW YORK, NY 10010<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2025-07-31 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [X] 10% Owner<br>[ ] Officer (give title below) [X] Other (specify below)<br>_* Director by Deputization_ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Larimar Therapeutics, Inc. [ LRMR ] | **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>DEERFIELD PARTNERS, L.P.<br><sub>(Last) (First) (Middle)</sub><br>345 PARK AVENUE SOUTH, 12TH FLOOR<br><sub>(Street)</sub><br>NEW YORK, NY 10010<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2025-07-31 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [X] 10% Owner<br>[ ] Officer (give title below) [X] Other (specify below)<br>_* Director by Deputization_ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Larimar Therapeutics, Inc. [ LRMR ] | **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 | 2025-07-31 |  | P |  | 3387529 | A | $3.20 | 9538918 | I | Through Deerfield Private Design Fund III, L.P.<sup>(1)(2)</sup> |
| Common Stock | 2025-07-31 |  | P |  | 3387539 | A | $3.20 | 9538945 | I | Through Deerfield Private Design Fund IV, L.P.<sup>(1)(2)</sup> |
| Common Stock | 2025-07-31 |  | P |  | 2599932 | A | $3.20 | 7321129 | I | Through Deerfield Healthcare Innovations Fund, L.P.<sup>(1)(2)</sup> |
| Common Stock |  |  |  |  |  |  |  | 4207982 | I | Through Deerfield Partners, L.P.<sup>(1)(2)</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 Form 4 is being filed by the undersigned as well as the entities listed on the Joint Filer Information Statement attached as an exhibit hereto (the "Reporting Persons"). Deerfield Mgmt III, L.P. is the general partner of Deerfield Private Design Fund III, L.P. ("Fund III"). Deerfield Mgmt IV, L.P. is the general partner of Deerfield Private Design Fund IV, L.P. ("Fund IV"). Deerfield Mgmt HIF, L.P. is the general partner of Deerfield Healthcare Innovations Fund, L.P. ("Deerfield HIF"). Deerfield Mgmt, L.P. is the general partner of Deerfield Partners, L.P. ("Deerfield Partners"). Deerfield Management Company, L.P. is the investment manager of Deerfield Partners, L.P., Fund III, Fund IV and Deerfield HIF (collectively, the "Funds"). James E. Flynn is the sole manager of the general partner of each of Deerfield Mgmt III, L.P., Deerfield Mgmt IV, L.P., Deerfield Mgmt HIF, L.P., Deerfield Mgmt, L.P. and Deerfield Management Company, L.P.

(2) In accordance with Instruction 4 (b)(iv) to Form 4, the entire amount of the Issuer's securities held by the Funds is reported herein. For purposes of Section 16 of the Securities Exchange Act of 1934, as amended, each Reporting Person disclaims beneficial ownership of any such securities, except to the extent of his/its indirect pecuniary interest therein, if any, and this report shall not be deemed an admission that such Reporting Person is the beneficial owner of such securities for purposes of Section 16 or otherwise.

**Remarks:**
Jonathan S. Leff, a partner in Deerfield Management, serves as a director of the Issuer.
Jonathan Isler, Attorney-in-Fact: Power of Attorney, which is hereby incorporated by reference to Exhibit 24 to a Form 3 with regard to BiomX Inc. filed with the Securities and Exchange Commission on March 19, 2024 by Deerfield Private Design Fund V, L.P., Deerfield Healthcare Innovations Fund II, L.P., Deerfield Mgmt V, L.P., Deerfield Mgmt HIF II, L.P., Deerfield Management Company, L.P. and James E. Flynn.

**Signature:** /s/ Jonathan Isler, Attorney-in-Fact  
**Date:** 2025-08-04

### 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.**