Mersana Therapeutics, Inc. — Director's Dealing 2017

Jun 28, 2017

SEC Form 3 — Initial Statement of Beneficial Ownership

Issuer: Mersana Therapeutics, Inc. (MRSN)
CIK: 0001442836
Period of Report: 2017-06-27

Reporting Person: Protopapas Anna (Director, President and CEO)

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	120302	Direct

Holdings (Derivative)

Security	Exercise Price	Expiration	Underlying	Shares	Ownership
Option to Purchase Common Stock	$1.53	2025-05-07	Common Stock (758783)		Direct
Option to Purchase Common Stock	$4.10	2026-08-29	Common Stock (158958)		Direct
Option to Purchase Common Stock	$6.98	2027-03-13	Common Stock (66666)		Direct
Series B-1 Convertible Preferred Stock	$		Common Stock (72263)		Indirect

Footnotes

F1: The original option grant for 879,085 option shares vested 25% on March 2, 2016 and in equal quarterly installments thereafter.

F2: The options vest in equal quarterly installments over the first four years after the vesting commencement date, July 1, 2016.

F3: The options vest in equal quarterly installments over the first four years after the vesting commencement date, March 14, 2017.

F4: Series B-1 Convertible Preferred Stock is convertible into shares of common stock at any time at the holder's election and automatically upon the consummation of a public offering of the registrant. There is no expiration date for the Series B-1 Convertible Preferred Stock.

F5: These securities are held in a trust for the benefit of the reporting person's children. The reporting person's spouse is trustee of the trust. The reporting person disclaims beneficial ownership of these securities, and the filing of this report is not an admission that the reporting person is the beneficial owner of these securities for purposes of Section 16 or for any other purpose.