Joint Filer Information

Names:	Deerfield Management Company, L.P.
Address:	780 Third Avenue, 37th Floor New York, NY 10017
Designated Filer:	James E. Flynn
Issuer and Ticker Symbol:	Homology Medicines, Inc. [FIXX]
Date of Event Requiring Statement:	June 6, 2019

The undersigned, Deerfield Management Company, L.P., is jointly filing the attached Statement of Changes in Beneficial Ownership on Form 4 with James E. Flynn with respect to the beneficial ownership of securities of Homology Medicines, Inc.

Signatures:

DEERFIELD MANAGEMENT COMPANY, L.P.

By:  Flynn Management LLC, General Partner

By: /s/ Jonathan Isler

      Jonathan Isler, Attorney-In-Fact