Eventide Asset Managment SC 13G/A Lexeo Therapeutics / EVENTIDE ASSET MANAGEMENT ownership change

EXHIBIT 1

WHEREAS, in accordance with Rule 13d-1(k)(1) under the Securities and Exchange Act of 1934 (the "Act"), only one joint Statement and any amendments thereto need to be filed whenever one or more persons are required to file such a Statement or any amendments thereto pursuant to Section 13(d) of the Act with respect to the same securities, provided that said persons agree in writing that such Statement or amendments thereto is filed on behalf of each of them;

NOW, THEREFORE, the parties hereto agree as follows:

Eventide Asset Management, LLC, Finny Kuruvilla, M.D., Ph. D. and Robin C. John do hereby agree, in accordance with Rule 13d-1(k)(1) under the Act, to file a Statement on Schedule 13G relating to their ownership of the Common Stock of the Issuer, and do hereby further agree that said Statement on Schedule 13G shall be filed on behalf of each of them.

	Eventide Asset Management, LLC
Date: August 9, 2024	By: /s/ Peter J. Luiso
	Name: Peter J. Luiso
	Title: General Counsel

	Finny Kuruvilla, M.D., Ph. D.
Date: August 9, 2024	By: /s/ Finny Kuruvilla, M.D., Ph. D.
	Name: Finny Kuruvilla, M.D., Ph. D.

	Robin C. John
Date: August 9, 2024	By: /s/ Robin C. John
	Name: Robin C. John