Summit Therapeutics Inc. 4

Co-CEO Robert W. Duggan bought 3,810,000 shares of Summit Therapeutics Inc. (SMMT) common stock on 2026-06-12 at $13.12 per share, a purchase of about $50 million, raising his direct holdings to 573,883,879 shares.

On June 12, 2026, Co-Chief Executive Officer Robert W. Duggan filed a Form 4 reporting an open-market purchase of 3,810,000 shares of Summit Therapeutics Inc. common stock at a price of $13.12 per share, for an aggregate value of approximately $49.98 million. Following this transaction, Duggan’s direct beneficial ownership increased to 573,883,879 shares. In addition, the filing notes indirect beneficial interests in several blocks of common stock held through related parties and trusts: 25,824,474 shares held by the Mahkam Zanganeh Revocable Trust, 76,680 shares held by an immediate family member of his spouse, 31,000 shares held directly by his spouse, and 10,199,776 shares held by the Shaun Zanganeh Irrevocable Trust, all of which Duggan disclaims beneficial ownership of except to the extent of any pecuniary interest. The large insider purchase significantly increases the CEO’s direct equity exposure to Summit Therapeutics.

Filing Facts

CIK

1599298

Ticker

SMMT

Form

4

Source Type

sec

Accession

0001055919-26-000007

Alert Tier

8