X0306 4 2021-06-15 0 0001420565 AILERON THERAPEUTICS INC ALRN 0001500210 Bailey Jeffrey Allen C/O AILERON THERAPEUTICS, INC. 285 SUMMER STREET, SUITE 101 BOSTON MA 02210 1 0 0 0 Stock Option (right to buy) 1.29 2021-06-15 4 A 0 96000 0.00 A 2031-06-14 Common Stock 96000 96000 D This option was granted on June 15, 2021. The shares underlying the option are scheduled to vest in full on the earlier of (i) June 15, 2022 or (ii) the date of the Issuer's 2022 Annual Meeting of Stockholders. /s/ Richard Wanstall, attorney-in-fact for Jeffrey Allen Bailey 2021-06-17