X0206 3 2017-06-28 0 0001420565 AILERON THERAPEUTICS INC ALRN 0001657662 KCK LTD. OMC CHAMBERS WICKHAMS CAY1, ROAD TOWN TORTOLA D8 VG1110 VIRGIN ISLANDS, BRITISH 0 0 1 0 Series E-3 Preferred Stock Common Stock 369977 D Series F Preferred Stock Common Stock 76839 D 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. /s/ Nael K. Kassar 2017-06-28