X0206 3 2017-06-28 0 0001420565 AILERON THERAPEUTICS INC ALRN 0001315797 Satter Muneer A C/O AILERON THERAPEUTICS, INC. 281 ALBANY STREET CAMBRIDGE MA 02139 0 0 1 0 Series D Preferred Stock Common Stock 85309 I See footnote Series E-2 Preferred Stock Common Stock 18511 I See footnote Series E-3 Preferred Stock Common Stock 16055 I See footnote Series F Preferred Stock Common Stock 24896 I See footnote 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. These shares are held by the Muneer A. Satter Revocable Trust for which the Reporting Person serves as trustee and, in such capacity, has sole voting and dispositive power over all such shares. /s/ Muneer A. Satter 2017-06-28