Timothy B. Lowinger - 05 Sep 2023 Form 4 Insider Report for Mersana Therapeutics, Inc. (MRSN)

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	MRSN	Restricted stock unit	Award	$0	+50,000		$0.000000	50,000	05 Sep 2023	Common Stock	50,000		Direct	F1, F2

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Id	Content
F1	Each restricted stock unit ("RSU") represents the contingent right to receive one share of common stock of the Issuer.
F2	The RSUs will vest on October 1, 2024, subject to the Reporting Person's continued service to the Issuer on such vesting date.