Timothy B. Lowinger - Jan 13, 2024 Form 4 Insider Report for Mersana Therapeutics, Inc. (MRSN)

Role
SVP, Chief Sci.&Tech. Officer
Signature
/s/ Alejandra Carvajal, Attorney-in-Fact
Stock symbol
MRSN
Transactions as of
Jan 13, 2024
Transactions value $
-$28,208
Form type
4
Date filed
1/17/2024, 05:19 PM
Previous filing
Sep 7, 2023

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction MRSN Common Stock Options Exercise $0 +9.38K +5.2% $0.00 190K Jan 13, 2024 Direct F1
transaction MRSN Common Stock Options Exercise $0 +4.79K +2.53% $0.00 195K Jan 14, 2024 Direct F2
transaction MRSN Common Stock Options Exercise $0 +7.29K +3.75% $0.00 202K Jan 15, 2024 Direct F3
transaction MRSN Common Stock Options Exercise $0 +7.92K +3.92% $0.00 210K Jan 15, 2024 Direct F4
transaction MRSN Common Stock Sale -$28.2K -10.4K -4.96% $2.71 199K Jan 16, 2024 Direct F5, F6

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 Options Exercise $0 -9.38K -25% $0.00 28.1K Jan 13, 2024 Common Stock 9.38K Direct F7, F8
transaction MRSN Restricted Stock Unit Options Exercise $0 -4.79K -33.34% $0.00 9.58K Jan 14, 2024 Common Stock 4.79K Direct F7, F9
transaction MRSN Restricted Stock Unit Options Exercise $0 -7.29K -50% $0.00 7.29K Jan 15, 2024 Common Stock 7.29K Direct F7, F10
transaction MRSN Restricted Stock Unit Options Exercise $0 -7.92K -100% $0.00* 0 Jan 15, 2024 Common Stock 7.92K Direct F7, F11
transaction MRSN Stock Option (Right to Buy) Award $0 +225K $0.00 225K Jan 15, 2024 Common Stock 225K $3.02 Direct F12
transaction MRSN Restricted Stock Unit Award $0 +50K $0.00 50K Jan 15, 2024 Common Stock 50K Direct F7, F13
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Buy Plan / Sale Plan: These are also open market purchases/sales of shares, but in this case the transaction is part of a trading plan. Rule 10b5-1 allows insiders to setup a trading plan to buy/sell stocks over a certain period of time. Since the purchases/sales are predetermined, this protects the insiders from violating insider trading law.

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).

Explanation of Responses:

Id Content
F1 Represents shares of common stock received upon vesting of a portion of the restricted stock units ("RSUs") awarded to the Reporting Person on January 13, 2023.
F2 Represents shares of common stock received upon vesting of a portion of the RSUs awarded to the Reporting Person on January 14, 2022.
F3 Represents shares of common stock received upon vesting of a portion of the RSUs awarded to the Reporting Person on January 15, 2021.
F4 Represents shares of common stock received upon vesting of a portion of the RSUs awarded to the Reporting Person on January 15, 2020.
F5 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 pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on May 10, 2023. The sale was effected through an automatic "sell to cover" transaction that did not represent a discretionary trade by the Reporting Person.
F6 The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $2.70 to $2.71, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer 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 this footnote.
F7 Each RSU represents the contingent right to receive one share of common stock of the Issuer.
F8 25% of the total number of RSUs granted vested on January 13, 2024, and the remainder shall vest thereafter in equal annual installments over the next three years.
F9 25% of the total number of RSUs granted vested on January 14, 2024, and the remainder shall vest thereafter in equal annual installments over the next two years.
F10 25% of the total number of RSUs granted vested on January 15, 2024, and the remainder shall vest on January 15, 2025
F11 Fully vested as of January 15, 2024.
F12 The option shall vest in equal quarterly installments over four years from the date of grant.
F13 The RSUs shall vest in equal annual installments over four years from the date of grant.