# EDGAR Filing Document

**Accession Number:** 0001834321
**File Stem:** 0001104659-23-004747
**Filing Date:** 2023-1
**Character Count:** 7623
**Document Hash:** 3b44034a072f50ab8b26e70d78de0c8e
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001104659-23-004747.hdr.sgml**: 20230118

**ACCESSION NUMBER**: 0001104659-23-004747

**CONFORMED SUBMISSION TYPE**: 4

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20230113

**FILED AS OF DATE**: 20230118

**DATE AS OF CHANGE**: 20230118

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Yang Arvin
- **CENTRAL INDEX KEY:** 0001834321

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-38129
- **FILM NUMBER:** 23535722

**MAIL ADDRESS:**
- **STREET 1:** 840 MEMORIAL DRIVE
- **CITY:** CAMBRIDGE
- **STATE:** MA
- **ZIP:** 02139
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Mersana Therapeutics, Inc.
- **CENTRAL INDEX KEY:** 0001442836
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **IRS NUMBER:** 000000000
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **STREET 1:** 840 MEMORIAL DRIVE
- **CITY:** CAMBRIDGE
- **STATE:** MA
- **ZIP:** 02139
- **BUSINESS PHONE:** 617-498-0020

**MAIL ADDRESS:**
- **STREET 1:** 840 MEMORIAL DRIVE
- **CITY:** CAMBRIDGE
- **STATE:** MA
- **ZIP:** 02139

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** MERSANA THERAPEUTICS INC
- **DATE OF NAME CHANGE:** 20080813

### 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>Yang Arvin<br><sub>(Last) (First) (Middle)</sub><br>C/O MERSANA THERAPEUTICS, INC.<br>840 MEMORIAL DRIVE<br><sub>(Street)</sub><br>CAMBRIDGE, MA 02139<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2023-01-13 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[ ] Director [ ] 10% Owner<br>[X] Officer (give title below) [ ] Other (specify below)<br>_SVP, Chief Medical Officer_ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Mersana Therapeutics, Inc. [ MRSN ] | **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 | 2023-01-14 |  | M<sup>(1)</sup> |  | 7084 | A | $0 | 33030 | D |  |
| Common Stock | 2023-01-17 |  | S<sup>(2)</sup> |  | 2209 | D | 5.74<sup>(3)</sup> | 30821 | D |  |

---

## 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) | $6.06 | 2023-01-13 |  | A |  | 217500 |  | <sup>(4)</sup> | 2033-01-12 | Common Stock | 217500 | $0 | 217500 | D |  |
| Restricted stock unit | <sup>(5)</sup> | 2023-01-13 |  | A |  | 48333 |  | <sup>(6)</sup> | <sup>(6)</sup> | Common Stock | 48333 | $0 | 48333 | D |  |
| Restricted stock unit | <sup>(5)</sup> | 2023-01-14 |  | M |  |  | 7084 | <sup>(7)</sup> | <sup>(7)</sup> | Common Stock | 7084 | $0 | 21249 | D |  |

---

### Footnotes:

(1) Represents shares of common stock received upon the vesting of a portion of the restricted stock units ("RSUs") awarded to the Reporting Person on January 14, 2022.

(2) Represents the sale of shares of common stock to satisfy the Reporting Person's tax withholding obligations in connection with the service-based vesting and settlement of the RSUs reported above. These sales were mandated by the Issuer's election under its equity incentive plans to require the Reporting Person to sell a number of shares of common stock needed to satisfy his tax withholding obligations and does not represent a discretionary trade by the Reporting Person.

(3) The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $5.74 to $5.78, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

(4) The option shall vest in equal quarterly installments over four years from the date of grant.

(5) Each RSU represents the contingent right to receive one share of common stock of the Issuer.

(6) The RSUs shall vest in equal annual installments over four years from the date of grant.

(7) 25% of the total number of RSUs granted vested on January 14, 2023, and the remainder shall vest thereafter in equal annual installments over the next three years.

**Signature:** /s/Alejandra Carvajal, as attorney-in-fact  
**Date:** 2023-01-18

### 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.**