X0306 4 2021-02-05 0 0001661998 Homology Medicines, Inc. FIXX 0001794702 Cohn Gabriel C/O HOMOLOGY MEDICINES, INC. ONE PATRIOTS PARK BEDFORD MA 01730 0 1 0 0 Chief Medical Officer Employee Stock Option (Right to Buy) 13.78 2021-02-05 4 A 0 78000 0.00 A 2031-02-05 Common Stock 78000 78000 D Restricted Stock Units 2021-02-05 4 A 0 13000 0.00 A Common Stock 13000 13000 D The option vests in 48 equal monthly installments on the first day of each calendar month following January 1, 2021. Each restricted stock unit represents a contingent right to receive one share of Issuer common stock. The restricted stock units will vest and settle as to one third of the restricted stock units on each of the first three anniversaries of January 1, 2021 so that such RSUs will become fully vested on January 1, 2024. /s/ Bradford Smith, Attorney-in-Fact for Gabriel Cohn, M.D. 2021-02-09