Jon Marc Wigginton - May 31, 2022 Form 4 Insider Report for Checkmate Pharmaceuticals, Inc. (CMPI)

Role: Director
Signature: /s/ Kleem Chaudhary, attorney-in-fact
Stock symbol: CMPI
Transactions as of: May 31, 2022
Transactions value $: $0
Form type: 4
Date filed: 5/31/2022, 10:02 AM
Previous filing: Feb 1, 2022
Next filing: Jun 8, 2022

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	CMPI	Stock Option (Right to Buy)	Disposed to Issuer		-20.1K	-100%		0	May 31, 2022	Common Stock	20.1K	$2.19	Direct	F1

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

Jon Marc Wigginton is no longer subject to Section 16 filing requirements. Form 4 or Form 5 obligations may continue.

Explanation of Responses:

Id	Content
F1	At the effective time of the merger contemplated by the Agreement and Plan of Merger dated April 18, 2022, among Checkmate Pharmaceuticals, Inc. (the "Issuer"), Regeneron Pharmaceuticals, and Scandinavian Acquisition Sub, Inc. (the "Merger"), each option granted by the Issuer to purchase Issuer Common Stock, whether or not vested, which has a per share exercise price that is less than $10.50 (each, an "In the Money Issuer Option") that was outstanding and unexercised as of immediately prior to the effective time of the Merger was cancelled and automatically converted into the right to receive an amount in cash equal to the product of (1) the total number of Issuer Common Stock subject to such In the Money Issuer Option and (2) the excess of $10.50 over the exercise price of such In the Money Issuer Option, subject to any required withholding of taxes.

Content

At the effective time of the merger contemplated by the Agreement and Plan of Merger dated April 18, 2022, among Checkmate Pharmaceuticals, Inc. (the "Issuer"), Regeneron Pharmaceuticals, and Scandinavian Acquisition Sub, Inc. (the "Merger"), each option granted by the Issuer to purchase Issuer Common Stock, whether or not vested, which has a per share exercise price that is less than $10.50 (each, an "In the Money Issuer Option") that was outstanding and unexercised as of immediately prior to the effective time of the Merger was cancelled and automatically converted into the right to receive an amount in cash equal to the product of (1) the total number of Issuer Common Stock subject to such In the Money Issuer Option and (2) the excess of $10.50 over the exercise price of such In the Money Issuer Option, subject to any required withholding of taxes.