X0609 4 2026-06-04 0 0001599298 Summit Therapeutics Inc. SMMT 0001507650 Zanganeh Mahkam false C/O SUMMIT THERAPEUTICS INC. 601 BRICKELL KEY DRIVE, SUITE 1000 MIAMI FL 33131 1 1 1 0 Co-Chief Executive Officer 0 Common Stock 2026-06-04 4 P 0 100000 14.60 A 25824474 I By the Mahkam Zanganeh Revocable Trust, with the Reporting Person as Trustee Common Stock 76680 I Immediate family member Common Stock 570073879 I By Spouse Common Stock 10199776 I By the Shaun Zanganeh Irrevocable Trust, with the Reporting Person as Trustee Common Stock 31000 D The Reporting Person disclaims beneficial ownership of these securities, except to the extent of her pecuniary interest therein, if any, and the inclusion of these securities in this report shall not be deemed an admission of beneficial ownership of all of the reported securities for purposes of Section 16 or for any other purpose. /s/ Mahkam Zanganeh 2026-06-04