AGREEMENT

EXHIBIT A

AGREEMENT

Pursuant to Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, the undersigned hereby agree that only one statement containing the information required by Schedule 13G need be filed with respect to the ownership by each of the undersigned of Common Stock of Cogent Biosciences, Inc.

Date: March 1, 2022				XXXXXXX LIFE SCIENCES PUBLIC FUND L.P.
				By: FHMLSP, L.P., its General Partner
				By: FHMLSP, L.L.C., its General Partner
				By:		/s/ Xxxxx X. Xxxxxx
						Xxxxx X. Xxxxxx, Chief Financial Officer
Date: March 1, 2022				FHMLSP, L.P.
				By: FHMLSP, L.L.C., its General Partner
				By:		/s/ Xxxxx X. Xxxxxx
						Xxxxx X. Xxxxxx, Chief Financial Officer
Date: March 1, 2022				FHMLSP, L.L.C.
				By:		/s/ Xxxxx X. Xxxxxx
						Xxxxx X. Xxxxxx, Chief Financial Officer
Date: March 1, 2022				By:		*
						Xxxxx X. Xxxxxx
Date: March 1, 2022				By:		*
						Xxxxxxx X. Xxxxx
Date: March 1, 2022				By:		**
						Xxxxxx Xxx
Date: March 1, 2022				By:		**
						Xxxxx Xxxxx
Date: March 1, 2022				*By:		/s/ Xxxxx X. Xxxxxx
						Xxxxx X. Xxxxxx, as Attorney-in-Fact

* This Schedule 13G was executed by Xxxxx X. Xxxxxx on behalf of the individuals listed above pursuant to a Power of Attorney, a copy of which was filed with the SEC on March 29, 2016.

** This Schedule 13G was executed by Xxxxx X. Xxxxxx on behalf of the individuals listed above pursuant to a Power of Attorney, a copy of which was filed with the SEC on August 16, 2021.