X0306 4 2018-05-15 0 0001420565 AILERON THERAPEUTICS INC ALRN 0001288231 LONGENECKER JOHN P PHD C/O AILERON THERAPEUTICS, INC. 281 ALBANY STREET CAMBRIDGE MA 02139 0 1 0 0 President and CEO Stock Option (right to buy) 5.50 2018-05-15 4 A 0 30000 0.00 A 2028-05-14 Common Stock 30000 30000 D This option was granted on May 15, 2018. The shares underlying the option are scheduled to vest in full on the earlier of (i) September 15, 2018 or (ii) the date on which Dr. Longenecker's employment is terminated in connection with the Company's hiring of a new chief executive officer. /s/ John P. Longenecker, Ph.D. 2018-05-17