JOINT FILING AGREEMENT The undersigned, MVIL, LLC is jointly filing the attached Form 4 with MORNINGSIDE VENTURE INVESTMENTS LIMITED with respect to the beneficial ownership of securities of Amylyx Pharmaceuticals, Inc. For and on behalf of MVIL, LLC...

                             JOINT FILING AGREEMENT

The undersigned, MVIL, LLC is jointly filing the attached Form 4 with
MORNINGSIDE VENTURE INVESTMENTS LIMITED with respect to the beneficial ownership
of securities of Amylyx Pharmaceuticals, Inc.

For and on behalf of

MVIL, LLC


By: /s/ Xxxxx Xxx Xxxx Xxxxx
    -------------------------
Xxxxx Xxx Xxxx Xxxxx, Manager