X0206 3 2017-06-28 0 0001420565 AILERON THERAPEUTICS INC ALRN 0001709926 Sigma Emerging Markets Ltd. OMC CHAMBERS, WICKHAMS CAY 1 ROAD TOWN, TORTOLA D8 VIRGIN ISLANDS, BRITISH 0 0 1 0 Series F Preferred Stock Common Stock 233086 D 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/ Rafael Urquia II 2017-06-28