As of April 28, 2026, Summit Therapeutics's top three insider holders are Robert W Duggan (Co Chief Executive Officer, 595.88Mn shares), Mahkam Zanganeh (Co Chief Executive Officer, 595.88Mn shares), Mahkam Zanganeh (Co Ceo President, 34.46Mn shares).
| Holder | Position | Shares (Direct) | Shares (Indirect) | Report Date |
|---|---|---|---|---|
| Mahkam Zanganeh | Co Chief Executive Officer | 0 | 595,875,033 | 23 Oct, 2025 |
| Robert W Duggan | Co Chief Executive Officer | 570,073,879 | 25,801,154 | 23 Oct, 2025 |
| Mahkam Zanganeh | Co Ceo President | 0 | 34,457,893 | 13 Mar, 2023 |
| Yu Xia | - | 0 | 32,057,147 | 23 Oct, 2025 |
| Mahkam Zanganeh | Co Chief Executive Officer | 0 | 10,199,776 | 03 Oct, 2024 |
| Manmeet Singh Soni | Coo And Cfo | 3,073,603 | 0 | 23 Oct, 2025 |
| Mahkam Zanganeh | Chief Executive Officer | 520,814 | 0 | 27 Mar, 2024 |
| Ankur Dhingra | Chief Financial Officer | 0 | 354,958 | 27 Mar, 2024 |
| Bhaskar Anand | Chief Accounting Officer | 159,751 | 0 | 23 Oct, 2025 |
| Jeff Huber | - | 0 | 44,052 | 13 Sep, 2024 |
| Ankur Dhingra | Chief Financial Officer | 38,057 | 0 | 17 Aug, 2022 |
* Please note that the shares above only reflect shares from the fund portfolio and the institutional portfolio. Shares from the personal portfolio are excluded from this Institutional Ownership Page. See these insiders' latest transactions here on Insider Page.
| Transaction Date | Insider Name | Security Class | Transaction Type | Shares Traded | Price | Shares Remaining | Ownership | Code |
|---|---|---|---|---|---|---|---|---|
| 08 Jan, 2026 | Bhaskar Anand | Stock Option (right to buy) | A | 30,000 | - | 30,000 | D | A |
| 02 Jan, 2026 | Robert W Duggan | Stock Option (right to buy) | A | 11,232 | $8.76 | 11,232 | D | A |
| 02 Jan, 2026 | Robert F. Booth | Stock Option (right to buy) | A | 35,000 | - | 35,000 | D | A |
| 02 Jan, 2026 | Kenneth A Clark | Stock Option (right to buy) | A | 35,000 | - | 35,000 | D | A |
| 02 Jan, 2026 | Alessandra Cesano | Stock Option (right to buy) | A | 35,000 | - | 35,000 | D | A |
| 02 Jan, 2026 | Yu Xia | Stock Option (right to buy) | A | 35,000 | - | 35,000 | D | A |
| 02 Jan, 2026 | Jeff Huber | Stock Option (right to buy) | A | 35,000 | - | 35,000 | D | A |
| 02 Jan, 2026 | Mostafa Ronaghi | Stock Option (right to buy) | A | 35,000 | - | 35,000 | D | A |
| 02 Jan, 2026 | Mahkam Zanganeh | Stock Option (right to buy) | A | 11,232 | $8.76 | 11,232 | I | A |
| 02 Jan, 2026 | Robert F. Booth | Stock Option (right to buy) | A | 7,180 | $8.76 | 7,180 | D | A |
| 02 Jan, 2026 | Alessandra Cesano | Stock Option (right to buy) | A | 3,219 | $8.76 | 3,219 | D | A |
| 02 Jan, 2026 | Kenneth A Clark | Stock Option (right to buy) | A | 17,796 | $8.76 | 17,796 | D | A |
| 02 Jan, 2026 | Jeff Huber | Stock Option (right to buy) | A | 9,885 | $8.76 | 9,885 | D | A |
| 21 Oct, 2025 | Robert W Duggan | Common Stock | A | 13,980,789 | $18.74 | 570,073,879 | D | A |
| 21 Oct, 2025 | Bhaskar Anand | Common Stock | A | 26,680 | $18.74 | 159,751 | D | A |
| 21 Oct, 2025 | Mahkam Zanganeh | Common Stock | A | 266,808 | $18.74 | 25,724,474 | I | A |
| 21 Oct, 2025 | Yu Xia | Common Stock | A | 533,617 | $18.74 | 32,057,147 | I | P |
| 21 Oct, 2025 | Manmeet Singh Soni | Common Stock | A | 53,361 | $18.74 | 3,073,603 | D | A |
| 21 Oct, 2025 | Robert W Duggan | Common Stock | A | 266,808 | $18.74 | 25,724,474 | I | A |
| 21 Oct, 2025 | Mahkam Zanganeh | Common Stock | A | 26,680 | $18.74 | 76,680 | I | P |