X0306 4 2021-09-14 0 0001693415 Translate Bio, Inc. TBIO 0001575933 Hughes Owen C/O TRANSLATE BIO, INC. 29 HARTWELL AVE LEXINGTON MA 02421 1 0 0 0 Common Stock 2021-09-14 4 S 0 29860 38.00 D 0 D Stock Option (right to buy) 7.39 2021-09-14 4 S 0 38135 0.00 D 2027-12-21 Common Stock 38135 0 D Stock Option (right to buy) 10.20 2021-09-14 4 S 0 18900 0.00 D 2029-06-17 Common Stock 18900 0 D Stock Option (right to buy) 15.33 2021-09-14 4 S 0 18900 0.00 D 2030-06-15 Common Stock 18900 0 D Stock Option (righ to buy) 20.43 2021-09-14 4 S 0 20000 0.00 D 2031-06-15 Common Stock 20000 0 D As of September 14, 2021, Issuer was acquired in a cash tender by an indirect subsidiary of Sanofi, a French societe anonyme at a purchase price of $38.00 per share (the "Tender Offer"), as described more fully in the Schedule 14D-9 filed by the Issuer on August 16, 2021. Under the terms of the Tender Offer, Issuer outstanding stock options, if not vested became vested, and all Issuer stock options were converted into cash consideration at the amount of the difference between the exercise price of the option and the Tender Offer price of $38.00 per share. The shares underlying this option became fully vested on March 9, 2021. This option was granted on June 18, 2019. The shares underlying this option became fully vested on the date of the Issuer's annual meeting of stockholders following the date of the grant, or June 16, 2020. This option was granted on June 16, 2020. The shares underlying this option became fully vested on the date of the Issuer's annual meeting of stockholders following the date of the grant, or June 16, 2021. This option was granted on June 16, 2021. This option will vest and become exercisable in full on the one year anniversary of the date of the award, or if earlier, the date of the Issuer's next annual meeting of stockholders following the date of the grant. /s/ Paul D. Burgess, as attorney-in-fact for Owen Hughes 2021-09-14