Abingworth SC 13D Adicet Bio / Abingworth ownership change

Exhibit 1

JOINT FILING AGREEMENT

This Agreement will confirm the agreement by and among the undersigned that the Schedule 13D filed with the Securities and Exchange Commission on the date hereof with respect to the beneficial ownership by the undersigned of the common stock of Adicet Bio, Inc. is being filed, and all amendments thereto will be filed, on behalf of each of the persons and entities named below, in accordance with Rule 13d-1 under the Securities Exchange Act of 1934, as amended. This Agreement may be executed in two or more counterparts, each of which shall be deemed an original, but all of which together shall constitute one and the same instrument.

Dated as of March 8, 2021

ABINGWORTH BIOVENTURES 8, LP

By: Abingworth LLP, its Manager

By: /s/ John Heard

Name: John Heard

Title: Authorized Signatory

ABINGWORTH LLP

By: /s/ John Heard

Name: John Heard

Title: Authorized Signatory