Mersana Therapeutics, Inc. — Director's Dealing 2021

Jul 20, 2021

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: Mersana Therapeutics, Inc. (MRSN)
CIK: 0001442836
Period of Report: 2021-07-15

Reporting Person: Kaufman Michael J. (Chief Manufacturing Officer)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2021-07-15	Common Stock	M	40000	—	Acquired	44710	Direct
2021-07-16	Common Stock	S	5776	$12.47	Disposed	38934	Direct
2021-07-19	Common Stock	S	6312	$12.02	Disposed	32622	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2021-07-15	Restricted Stock Units	$	M	40000	Disposed		Common Stock (40000)	Direct

Footnotes

F1: Each restricted stock unit ("RSU") listed in Table II represented a contingent right to receive one share of the Issuer's common stock upon vesting.

F2: Represents the number of shares sold by the reporting person to cover tax withholding obligations in connection with the vesting of the RSUs listed in Table II. 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 her tax withholding obligations and does not represent a discretionary trade by the reporting person

F3: The price reported in Column 4 is a weighted-average price. These shares were sold in multiple transactions at prices ranging from $12.27 to $12.61, inclusive. The reporting person undertakes to provide to Mersana Therapeutics, Inc., any security holder of Mersana Therapeutics, Inc., 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 footnote (3) to this Form 4.

F4: The price reported in Column 4 is a weighted-average price. These shares were sold in multiple transactions at prices ranging from $11.90 to $12.23, inclusive. The reporting person undertakes to provide to Mersana Therapeutics, Inc., any security holder of Mersana Therapeutics, Inc., 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 footnote (4) to this Form 4.

F5: The RSUs vested in their entirety on July 15, 2021.