X0206 3 2017-06-28 0 0001420565 AILERON THERAPEUTICS INC ALRN 0001297709 Novartis Bioventures Ltd C/O NOVARTIS INTERNATIONAL AG WSJ-200.220 BASEL V8 CH-4002 SWITZERLAND 0 0 1 0 0001114448 NOVARTIS AG LICHTSTRASSE 35 BASEL V8 CH 4056 SWITZERLAND 0 0 1 0 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 Series E-2 Preferred Stock Common Stock 266132 D Series E-3 Preferred Stock Common Stock 230837 D Series F Preferred Stock Common Stock 372937 D 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. The Series E-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 E-3 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 F 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 board of directors of Novartis Bioventures Ltd. has sole voting and investment control and power over such securities. None of the members of its board of directors has individual voting or investment power with respect to such securities and each disclaims beneficial ownership of such securities. Novartis Bioventures Ltd. is an indirectly owned subsidiary of Novartis AG. /s/ H.S. Zivi 2017-06-28 /s/ Laurieann Chaikowsky 2017-06-28