X0306 4 2016-03-29 0 0001631650 Aimmune Therapeutics, Inc. AIMT 0001253886 ENRIGHT PATRICK G C/O LONGITUDE CAPITAL PARTNERS II, LLC 800 EL CAMINO REAL, SUITE 220 MENLO PARK CA 94025 1 0 1 0 Common Stock, $0.0001 par value 2016-03-29 4 P 0 33064 13.4986 A 7467694 I By Longitude Venture Partners II, L.P. Common Stock, $0.0001 par value 2016-03-29 4 P 0 45440 14.1465 A 7513134 I By Longitude Venture Partners II, L.P. Reflects purchases of ordinary shares executed in multiple transactions at prices ranging from $12.90 to $13.89. The price reported reflects the weighted average purchase price. The Reporting Person hereby undertakes to provide upon request to the Securities and Exchange Commission staff, the Issuer or a security holder of the Issuer full information regarding the number of shares and prices at which the purchases were effected. The shares are held by Longitude Venture Partners II, L.P. ("Longitude Venture II"). Longitude Capital Partners II, LLC ("Longitude Capital II") is the general partner of Longitude Venture II and may be deemed to have sole voting, investment and dispositive power over the shares held by Longitude Venture II. Patrick G. Enright is a managing member of Longitude Capital II and in his capacity as such may be deemed to exercise shared voting and investment power over the shares held by Longitude Venture II. Mr. Enright disclaims beneficial ownership of such shares except to the extent of his pecuniary interest therein. Reflects purchases of ordinary shares executed in multiple transactions at prices ranging from $13.90 to $14.29. The price reported reflects the weighted average purchase price. The Reporting Person hereby undertakes to provide upon request to the Securities and Exchange Commission staff, the Issuer or a security holder of the Issuer full information regarding the number of shares and prices at which the purchases were effected. /s/ Warren L. DeSouza, as Attorney-in-Fact for Patrick G. Enright 2016-03-31