Data spanning the past 90 days through January 09, 2026 reveals that Summit Therapeutics's three principal insider shareholders consist of Chief Executive Officer Mahkam Zanganeh (570.59Mn shares), Co Chief Executive Officer Robert W Duggan (570.15Mn shares), Director Yu Xia (32.06Mn shares).
| Holder | Position | Shares | Report Date |
|---|---|---|---|
| Mahkam Zanganeh | Chief Executive Officer | 570,594,693 | 27 Mar, 2024 |
| Robert W Duggan | Co Chief Executive Officer | 570,150,559 | 23 Oct, 2025 |
| Yu Xia | 32,057,147 | 23 Oct, 2025 | |
| Manmeet Singh Soni | Coo And Cfo | 3,073,603 | 23 Oct, 2025 |
| Ankur Dhingra | Chief Financial Officer | 394,485 | 08 Mar, 2023 |
| Bhaskar Anand | Chief Accounting Officer | 159,751 | 23 Oct, 2025 |
| Jeff Huber | 44,052 | 13 Sep, 2024 |
* 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 |
|---|---|---|---|---|---|---|---|---|
| 21 Oct, 2025 | Robert W Duggan | Common Stock | A | 26,680 | $18.74 | 76,680 | I | P |
| 21 Oct, 2025 | Robert W Duggan | Common Stock | A | 266,808 | $18.74 | 25,724,474 | I | A |
| 21 Oct, 2025 | Robert W Duggan | Common Stock | A | 13,980,789 | $18.74 | 570,073,879 | D | A |
| 21 Oct, 2025 | Mahkam Zanganeh | Common Stock | A | 26,680 | $18.74 | 76,680 | I | P |
| 21 Oct, 2025 | Mahkam Zanganeh | Common Stock | A | 13,980,789 | $18.74 | 570,073,879 | I | A |
| 21 Oct, 2025 | Mahkam Zanganeh | Common Stock | A | 266,808 | $18.74 | 25,724,474 | I | A |
| 21 Oct, 2025 | Manmeet Singh Soni | Common Stock | A | 53,361 | $18.74 | 3,073,603 | D | A |
| 21 Oct, 2025 | Bhaskar Anand | Common Stock | A | 26,680 | $18.74 | 159,751 | D | A |
| 21 Oct, 2025 | Yu Xia | Common Stock | A | 533,617 | $18.74 | 32,057,147 | I | P |
| 11 Sep, 2025 | Robert W Duggan | Common Stock | A | 5,000 | $18.07 | 556,093,090 | D | P |
| 11 Sep, 2025 | Mahkam Zanganeh | Common Stock | A | 5,000 | $18.07 | 556,093,090 | I | P |
| 10 Sep, 2025 | Robert W Duggan | Common Stock | A | 333,394 | $17.68 | 556,088,090 | D | P |
| 10 Sep, 2025 | Mahkam Zanganeh | Common Stock | A | 333,394 | $17.68 | 556,088,090 | I | P |
| 30 May, 2025 | Robert W Duggan | Common Stock | A | 74,545 | $2.64 | 555,754,696 | D | M |
| 30 May, 2025 | Mahkam Zanganeh | Common Stock | A | 74,545 | $2.64 | 555,754,696 | I | M |
| 08 Apr, 2025 | Robert W Duggan | Common Stock | A | 3,985,055 | $1.58 | 555,680,151 | D | X |
| 08 Apr, 2025 | Mahkam Zanganeh | Common Stock | A | 3,985,055 | $1.58 | 555,680,151 | I | X |
| 03 Oct, 2024 | Mahkam Zanganeh | Common Stock | A | 315,681 | $1.58 | 10,199,776 | I | X |
| 11 Sep, 2024 | Robert W Duggan | Common Stock | A | 3,325,991 | $22.70 | 551,695,096 | D | A |
| 11 Sep, 2024 | Jeff Huber | Common Stock | A | 44,052 | $22.70 | 44,052 | I | A |