X0306 4 2017-09-25 0 0001631650 Aimmune Therapeutics, Inc. AIMT 0001389147 DILLY STEPHEN GEORGE AIMMUNE THERAPEUTICS, INC. 8000 MARINA BOULEVARD, SUITE 300 BRISBANE CA 94005-1884 1 1 0 0 President and CEO Common Stock, $0.0001 par value 2017-08-23 5 G 0 E 41075 0.00 D 10328 I By GRAT 1 Common Stock, $0.0001 par value 2017-08-23 5 G 0 E 41075 0.00 A 41075 I By Child's Trust 1 Common Stock, $0.0001 par value 2017-08-23 5 G 0 E 10328 0.00 D 0 I By GRAT 1 Common Stock, $0.0001 par value 2017-08-23 5 G 0 E 10328 0.00 A 10328 I By Family Trust Common Stock, $0.0001 par value 2017-08-23 5 G 0 E 41075 0.00 D 10328 I By Wife's GRAT 1 Common Stock, $0.0001 par value 2017-08-23 5 G 0 E 41075 0.00 A 41075 I By Child's Trust 2 Common Stock, $0.0001 par value 2017-08-23 5 G 0 E 10328 0.00 D 0 I By Wife's GRAT 1 Common Stock, $0.0001 par value 2017-08-23 5 G 0 E 10328 0.00 A 20656 I By Family Trust Common Stock, $0.0001 par value 2017-09-25 4 S 0 100000 25.0079 D 515308 D Common Stock, $0.0001 par value 14447 I By GRAT 2 Common Stock, $0.0001 par value 14447 I By Wife's GRAT 2 This transaction involved a gift of securities previously held indirectly by Stephen G. Dilly, as Trustee of The Stephen G. Dilly 2015 Grantor Retained Annuity Trust dated June 23, 2015 (the "First Dilly Trust"). Such shares were transferred from the First Dilly Trust to Stephen G. Dilly and Edwina Lynette Mullens as Trustees of The Frederick S W Dilly 2015 Irrevocable Trust dated June 23, 2015 (the "Frederick S W Dilly Trust") on August 23, 2017. These shares are held by the First Dilly Trust. Dr. Dilly has sole voting, investment and dispositive power over the shares held by the First Dilly Trust. These shares are held by the Frederick S W Dilly Trust. Dr. Dilly and Ms. Mullens have joint voting, investment and dispositive power over the shares held by the Frederick S W Dilly Trust. These shares are held by Stephen G. Dilly and Edwina Lynette Mullens as Trustees of The Dilly Family Trust dated October 9, 2002 (the "Family Trust"). Dr. Dilly and Ms. Mullens have joint voting, investment and dispositive power over the shares held by the Family Trust. This transaction involved a gift of securities previously held indirectly by Edwina Lynette Mullens, as Trustee of The Edwina Lynette Mullens 2015 Grantor Retained Annuity Trust dated June 23, 2015 (the "First Mullens Trust"). Such shares were transferred from the First Mullens Trust to Edwina Lynette Mullens and Stephen G. Dilly as Trustees of The Harriet F.L. Dilly 2015 Revocable Trust dated June 23, 2015 (the "Harriet F.L. Dilly Trust") on August 23, 2017. Dr. Dilly disclaims beneficial ownership of the shares held by Ms. Mullens. These shares are held by the First Mullens Trust. Ms. Mullens has sole voting, investment and dispositive power over the shares held by the First Mullens Trust. Dr. Dilly disclaims beneficial ownership of the shares held by the First Mullens Trust. These shares are held by the Harriet F.L. Dilly Trust. Dr. Dilly and Ms. Mullens have joint voting, investment and dispositive power over the shares held by the Frederick S W Dilly Trust. This sale was effected pursuant to a Rule 10b5 1 trading plan adopted by the Reporting Person. The transaction was executed in multiple trades in prices ranging from $24.90 to $25.33, inclusive. The price reported in Column 4 above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a stockholder of the Issuer, information regarding the number of shares and prices at which the transaction was effected. A portion of these shares is subject to a right of repurchase held by the Issuer. These shares are held by Stephen G. Dilly, Trustee, The Stephen G. Dilly 2016 Grantor Retained Annuity Trust DTD August 12, 2016 (the "Second Dilly Trust"). Dr. Dilly has sole voting, investment and dispositive power over the shares held by the Second Dilly Trust. These shares are held by Edwina Lynette Mullens, Trustee, The Edwina Lynette Mullens 2016 Grantor Retained Annuity Trust DTD August 12, 2016 (the "Second Mullens Trust"). Ms. Mullens has sole voting, investment and dispositive power over the shares held by the Second Mullens Trust. Dr. Dilly disclaims beneficial ownership of the shares held by the Second Mullens Trust. /s/ Douglas T. Sheehy, as Attorney-in-Fact for Stephen G. Dilly 2017-09-27