EXHIBIT 2

AGREEMENT OF JOINT FILING

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 13D need be filed with respect to the ownership by each of the undersigned of shares of Common Stock of Prime Medicine, Inc.

This Agreement may be executed in any number of counterparts, each of which shall be deemed an original.

Date:        February 10, 2025

ARCH VENTURE FUND XIII, L.P.

By:    ARCH Venture Partners XIII, L.P.

its General Partner

By:    ARCH Venture Partners XIII, LLC

its General Partner

By:                  *                            

Keith Crandell

Managing Director

ARCH VENTURE PARTNERS XIII, L.P.

By:  ARCH Venture Partners XIII, LLC

its General Partner

By:                  *                             

Keith Crandell

Managing Director

ARCH VENTURE PARTNERS XIII, LLC

By:                   *                             

Keith Crandell

Managing Director

Keith Crandell

Robert Nelsen

Kristina Burow

Paul Berns

* By:  /s/ Mark McDonnell            

Mark McDonnell as

Attorney-in-Fact

*          This Agreement of Joint Filing was executed by Mark McDonnell pursuant to a Power of Attorney filed as Exhibit 24.1 to the Form 3 relating to the beneficial ownership of shares of Metsera, Inc. by the Reporting Persons filed with the Securities Exchange Commission on January 30, 2025 and incorporated herein in its entirety by reference.

Metsera, Inc. SCHEDULE 13D