X0306 4 2019-08-16 0 0001420565 AILERON THERAPEUTICS INC ALRN 0001466794 Vukovic Vojo C/O AILERON THERAPEUTICS, INC. 490 ARSENAL WAY, SUITE 210 WATERTOWN MA 02472 0 1 0 0 SVP, Chief Medical Officer Common Stock 2019-08-16 4 P 0 75000 0.5927 A 75000 D The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $0.5890 per share to $0.5980 per share, inclusive. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote. /s/ Vojislav Vukovic 2019-08-20