X0206 3 2017-06-28 0 0001420565 AILERON THERAPEUTICS INC ALRN 0001143789 APPLE TREE PARTNERS II LP 47 HULFISH STREET SUITE 441 PRINCETON NJ 08542 0 0 1 0 Common Stock 251 D Series A Preferred Stock Common Stock 12579 D Series A-1 Preferred Stock Common Stock 6192 D Series B Preferred Stock Common Stock 372955 D Series C Preferred Stock Common Stock 298583 D Series C-2 Preferred Stock Common Stock 426547 D Series D Preferred Stock Common Stock 682476 D The Series A Preferred Stock is convertible into Common Stock on a 99.37-for-one basis into the number of shares of Common Stock shown in column 3 at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering. The shares have no expiration date. The Series A-1 Preferred Stock is convertible into Common Stock on a 99.37-for-one basis into the number of shares of Common Stock shown in column 3 at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering. The shares have no expiration date. The Series B Preferred Stock is convertible into Common Stock on a 9.937-for-one basis into the number of shares of Common Stock shown in column 3 at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering. The shares have no expiration date. The Series C Preferred Stock is convertible into Common Stock on a 9.937-for-one basis into the number of shares of Common Stock shown in column 3 at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering. The shares have no expiration date. The Series C-2 Preferred Stock is convertible into Common Stock on a 9.937-for-one basis into the number of shares of Common Stock shown in column 3 at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering. The shares have no expiration date. The Series D Preferred Stock is convertible into Common Stock on a 9.937-for-one basis into the number of shares of Common Stock shown in column 3 at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering. The shares have no expiration date. Dr. Seth L. Harrison is a principal of the general partner of Apple Tree Partners II, L.P., and Dr. Harrison disclaims beneficial ownership of the shares held by Apple Tree Partners II, L.P., except to the extent of his pecuniary interest therein. Dr. Harrison has sole voting and investment power over the shares held by Apple Tree Partners II, L.P. /s/ Dr. Seth L. Harrison 2017-06-28