X0306 4 2019-06-18 0 0001693415 Translate Bio, Inc. TBIO 0001030575 FORMELA JEAN FRANCOIS C/O TRANSLATE BIO, INC. 29 HARTWELL AVE LEXINGTON MA 02421 1 0 0 0 Stock Option (right to buy) 10.20 2019-06-18 4 A 0 18900 0.00 A 2029-06-17 Common Stock 18900 18900 D This stock 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. This option was granted to the Reporting Person, a director of the Issuer. The proceeds of any sale of shares of common stock issued to the Reporting Person upon exercise of this option will be transferred to Atlas Venture Advisors Inc. and as such, the Reporting Person disclaims ownership of such securities reported herein for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, except to the extent of his pecuniary interest therein, if any /s/ Frank Castellucci, as attorney in fact for Jean-Francois Formela 2019-06-19