X0306 4 2017-07-05 1 0001420565 AILERON THERAPEUTICS INC ALRN 0000889131 ROCHE HOLDING LTD GRENZACHERSTRASSE 122 BASEL V8 CH4070 SWITZERLAND 0 0 1 0 0001053942 ROCHE FINANCE LTD GRENZACHERSTRASSE 124 BASEL V8 CH4070 SWITZERLAND 0 0 1 0 Common Stock 2017-07-05 4 C 0 579093 A 582963 D Common Stock 2017-07-05 4 P 0 119400 15.00 A 702363 D Series D Preferred Stock 2017-07-05 4 C 0 3390885 0.00 D Common Stock 341238 0 D Series E-2 Preferred Stock 2017-07-05 4 C 0 735775 0.00 D Common Stock 74043 0 D Series E-3 Preferred Stock 2017-07-05 4 C 0 638194 0.00 D Common Stock 64224 0 D Series F Preferred Stock 2017-07-05 4 C 0 989594 0.00 D Common Stock 99586 0 D The Series D, Series E-2, Series E-3 and Series F Preferred Stock converted into Common Stock on a 9.937-for-one basis upon the closing of the Issuer's initial public offering without payment of consideration. The Series D, Series E-2, Series E-3 and Series F Preferred Stock were convertible at any time at the holder's election and automatically upon the closing of the Issuer's initial pubic offering. The shares had no expiration date. Roche Finance Ltd is the direct beneficial owner of these securities of the Issuer, except for 3,870 shares of Common Stock held by Genentech, Inc., for which Roche Finance Ltd exercises voting and investment control. Roche Finance Ltd is a wholly owned subsidiary of Roche Holding Ltd. Roche Holding Ltd is the indirect beneficial owner of these securities of the Issuer. Each Reporting Person disclaims beneficial ownership of the securities except to the extent of its pecuniary interest therein, if any. Each Reporting Person also disclaims beneficial ownership of any securities of the Issuer that may be or are beneficially owned by any other person or persons other than such Reporting Person. This Form 4 shall not be deemed an admission that any Reporting Person or other person is a beneficial owner of any securities of the Issuer for any purpose, other than the securities reported in this Form 4. /s/ Carole Nuechterlein, authorized signatory 2017-07-05 /s/ Andreas Knierzinger, authorized signatory 2017-07-05