Summit Therapeutics Inc. — Director's Dealing 2025

May 2, 2025

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: Summit Therapeutics Inc. (SMMT)
CIK: 0001599298
Period of Report: 2025-04-29

Reporting Person: Zanganeh Mahkam (Director, Co-Chief Executive Officer, 10% Owner)

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2025-04-29	Stock Option (right to buy)	$1.06	A	1040000	Acquired	2032-06-28	Common Stock (1040000)	Direct
2025-04-29	Stock Option (right to buy)	$1.29	A	400000	Acquired	2032-09-09	Common Stock (400000)	Direct
2025-04-29	Stock Option (right to buy)	$1.68	A	9590558	Acquired	2033-10-13	Common Stock (9590558)	Direct

Footnotes

F1: Effective April 29, 2025, these stock options were amended from performance-based stock options to time-based stock options. The shares underlying the option vest as follows: (i) 50% of such shares vested as of April 29, 2025, and (ii) the remaining 50% of such shares vest in three equal annual installments, with the first such installment occurring on October 13, 2025.

F2: Not applicable.