v3.26.1
Pay vs Performance Disclosure - USD ($)
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Pay vs Performance Disclosure          
Pay vs Performance Disclosure, Table
Value of Initial Fixed $100 Investment Based On:
Year
Summary
Compensation
Table Total for
PEO-RD (1) (2)
Summary
Compensation
Table Total for
PEO-MZ (1) (2)(6)
Compensation
Actually Paid
to PEO-RD (1)(3)(5)
Compensation
Actually Paid
to PEO-MZ (1)(5)(6)
Average
Summary
Compensation
Table Total for
Non-PEO
NEO (2)(4)(6)(7)
Average
Compensation
Actually Paid
to Non-PEO
NEO (4)(5)(6)(7)
Company Total
Shareholder
Return
(TSR) (8)
Peer Group TSR (9)
Net Income (Loss)
2025
$172,376 $246,047,279 $172,376 $233,109,816 $249,127,782 $238,006,634 $372.13 $119.92 $(1,079,586,000)
2024$158,613 $1,161,021 $158,613 $228,307,722 $2,514,385 $133,810,518 $379.57 $113.68 $(221,315,000)
2023$— $20,562,924 $— $30,062,629 $12,049,222 $18,441,114 $55.53 $115.84 $(614,928,000)
2022$— $1,242,049 $— $3,786,649 $1,362,850 $3,502,186 $90.43 $111.67 $(78,782,000)
2021$— $9,639,214 $— $5,123,646 $1,325,423 $(11,289)$57.23 $126.42 $(88,602,000)
        
Named Executive Officers, Footnote
For 2025, 2024, 2023, and 2022 the principal executive officers (PEOs) were Robert W. Duggan (Co-Chief Executive Officer and Chairman) and Mahkam Zanganeh (Co-Chief Executive Officer, President and Director).
For 2022, the sole non-PEO NEO was Ankur Dhingra, our former Chief Financial Officer who served in such role from May 2022 to April 2024. For 2024 and 2023, the non-PEO NEOs were Manmeet Soni (Chief Operating Officer, Chief Financial Officer and Director) and Ankur Dhingra (former Chief Financial Officer). Mr. Soni has served as Chief Operating Officer since October 2023 and as Chief Financial Officer since April 2024. For 2025, the non-PEO NEO was Mr. Soni. 		       
Peer Group Issuers, Footnote
The Peer Group TSR is calculated based on the Nasdaq Biotechnology Index, which is the same index that we used in the performance graph included in Item 5 of our Annual Report on Form 10-K for the year ended December 31, 2025.
        
Adjustment To PEO Compensation, Footnote Amounts represent the “Total” column set forth in the Summary Compensation Table (“SCT”). See the footnotes to the SCT for further detail regarding the amounts in these columns.
The dollar amounts reported in these columns represent the amounts of “Compensation Actually Paid” (otherwise known as “CAP”). The Amounts are computed in accordance with Item 402(v) of Regulation S-K by deducting and adding the amounts from the “Total” column of the SCT as shown in the below tables (pursuant to SEC rules, fair value at each measurement date is computed in a manner consistent with the fair value methodology used to account for share-based payments in our financial statements under GAAP).
If the achievement of the performance condition for the performance-based stock options was not probable, as defined under applicable accounting guidance, then we assigned a fair value of $0. In April 2025, performance-based stock options were modified to require only the service-based vesting requirements to continue to be satisfied in order to become fully vested.
2025
PEO-RD (1)
PEO-MZ (1)
Non-PEO NEO (4)
Summary Compensation Table Total (2)
$172,376 $246,047,279 $249,127,782 
Deduct: SCT “Option Awards Modification” column value
— (245,021,384)(248,101,887)
Add: change in fair value of equity awards granted in prior years that are outstanding and unvested as of the fiscal year end (10)
— (2,717,693)(3,575,833)
Add: change in fair value of equity awards granted in prior years that vested during the fiscal year end as of the vesting date (10)
— 14,689,022 17,807,935 
Add: excess fair value for performance award modifications
— 220,112,592 222,748,637 
Compensation Actually Paid (5)
$172,376 $233,109,816 $238,006,634 
        
Non-PEO NEO Average Total Compensation Amount $ 249,127,782 $ 2,514,385 $ 12,049,222 $ 1,362,850 $ 1,325,423
Non-PEO NEO Average Compensation Actually Paid Amount $ 238,006,634 133,810,518 18,441,114 3,502,186 (11,289)
Adjustment to Non-PEO NEO Compensation Footnote
The dollar amounts reported in these columns represent the amounts of “Compensation Actually Paid” (otherwise known as “CAP”). The Amounts are computed in accordance with Item 402(v) of Regulation S-K by deducting and adding the amounts from the “Total” column of the SCT as shown in the below tables (pursuant to SEC rules, fair value at each measurement date is computed in a manner consistent with the fair value methodology used to account for share-based payments in our financial statements under GAAP).
If the achievement of the performance condition for the performance-based stock options was not probable, as defined under applicable accounting guidance, then we assigned a fair value of $0. In April 2025, performance-based stock options were modified to require only the service-based vesting requirements to continue to be satisfied in order to become fully vested.
In April 2024, our former Chief Financial Officer, Ankur Dhingra, resigned and forfeited certain equity awards granted to him.
2025
PEO-RD (1)
PEO-MZ (1)
Non-PEO NEO (4)
Summary Compensation Table Total (2)
$172,376 $246,047,279 $249,127,782 
Deduct: SCT “Option Awards Modification” column value
— (245,021,384)(248,101,887)
Add: change in fair value of equity awards granted in prior years that are outstanding and unvested as of the fiscal year end (10)
— (2,717,693)(3,575,833)
Add: change in fair value of equity awards granted in prior years that vested during the fiscal year end as of the vesting date (10)
— 14,689,022 17,807,935 
Add: excess fair value for performance award modifications
— 220,112,592 222,748,637 
Compensation Actually Paid (5)
$172,376 $233,109,816 $238,006,634 
        
Total Shareholder Return Amount $ 372.13 379.57 55.53 90.43 57.23
Peer Group Total Shareholder Return Amount 119.92 113.68 115.84 111.67 126.42
Net Income (Loss) $ (1,079,586,000) (221,315,000) (614,928,000) (78,782,000) (88,602,000)
Additional 402(v) Disclosure
PAY VERSUS PERFORMANCE

As required by Section 953(a) of the Dodd-Frank Wall Street Reform and Consumer Protection Act and Item 402(v) of Regulation S-K, we are providing the following information about the relationship between NEO compensation and certain financial performance of our Company. The disclosure included in this section is prescribed by SEC rules and does not necessarily align with how the Company or the Compensation Committee view the link between the Company’s performance and its NEOs' pay.
Mr. Duggan has declined any compensation from the Company for his role as Co-Chief Executive Officer. The options received in 2025 and 2024 relate to Board of Directors fees. Mr. Duggan received 10,724 and 74,545 options with an aggregate grant date fair value of $172,376 and $158,613 which fully vested as of December 31, 2025 and December 31, 2024, respectively.
Total Shareholder Return illustrates the value, as of the last day of the indicated fiscal year, of an investment of $100 in our common stock on December 31, 2021.
Excludes change in fair value of equity awards modified in 2025, which is included in line “Add: excess fair value for performance award modifications.”
Pay Versus Performance Narrative Disclosure
In accordance with Item 402(v) of Regulation S-K, we are providing the following descriptions of the relationships between information presented in the Pay Versus Performance table on CAP and each of total shareholder return (“TSR”) and net loss.

We do not link our PEOs and NEO compensation to the Company’s financial and stock price performance. As a development stage company, we link a significant portion of their compensation to the achievement of key product development milestones. Although we are required to show the relationship between our compensation program and net income (or loss, as applicable), we do not consider net income (loss) to be a relevant or driving metric for NEO compensation, as our NEO compensation program is not determined by this financial performance measure.

For purposes of this disclosure, there were no financial performance measures used to link Company performance to Compensation Actually Paid to our PEOs and non-PEO NEO in 2025.

Description of Relationships Between Pay and Performance

The following table shows the relationship between compensation actually paid to our Co-Chief Executive Officers and the average compensation paid to our other NEOs, to each of net income, relative total stockholder return and our peer group total stockholder return, in 2025, 2024, 2023, 2022 and 2021:

Year ended December 31,
Year-over-Year Changes
2025
2024
2023
2022
2021
2025
2024
2023
2022
Financial Results:
Net Income (Loss)$(1,079,586,000)$(221,315,000)$(614,928,000)$(78,782,000)$(88,602,000)388 %(64)%681 %(11)%
Total Stockholders' Return:
Summit Therapeutics, Inc.$372 $380 $56 $90 $57 (2)%584 %(39)%58 %
Peer Group (Nasdaq Biotechnology Index)$120 $215 $167 $117 $174 (44)%29 %43 %(33)%
Compensation Actually Paid to:
Co-Chief Executive Officers (1)
$233,282,192 $228,466,335 $30,062,629 $3,786,649 $5,123,646 2 %660 %694 %(26)%
Other NEOs (average)$238,006,634 $133,810,518 $18,441,114 $3,502,186 $(11,289)78 %626 %427 %(31,123)%
(1)For 2025, 2024, 2023, and 2022 includes Robert W. Duggan (Co-Chief Executive Officer and Chairman) and Mahkam Zanganeh (Co-Chief Executive Officer, President and Director).

Disclosure of the Most Important Performance Measures

We are a pre-revenue biopharmaceutical company focused on the discovery, development, and commercialization of patient-, physician-, caregiver- and societal-friendly medicinal therapies intended to improve quality of life, increase potential duration of life, and resolve serious unmet medical needs. Therefore, there were no financial measures used to link Company performance to Compensation Actually Paid to our Co-Chief Executive Officer (PEO) and Other NEOs in 2025, 2024, 2023, 2022 and 2021.

We use a range of non-financial performance metrics to determine NEO compensation, with a focus on the Company’s long-term sustainability, growth, and success. These metrics include the achievement of annual OKRs, which are tied to meeting regulatory milestones, overseeing clinical trial progress, managing operational and manufacturing goals, as well as effective budget management and capital raising efforts.
        
Duggan [Member]          
Pay vs Performance Disclosure          
PEO Total Compensation Amount $ 172,376 158,613      
PEO Actually Paid Compensation Amount $ 172,376 $ 158,613      
PEO Name Robert W. Duggan Robert W. Duggan      
Zanganeh [Member]          
Pay vs Performance Disclosure          
PEO Total Compensation Amount $ 246,047,279 $ 1,161,021 20,562,924 1,242,049 9,639,214
PEO Actually Paid Compensation Amount $ 233,109,816 $ 228,307,722 $ 30,062,629 $ 3,786,649 $ 5,123,646
PEO Name Mahkam Zanganeh Mahkam Zanganeh Mahkam Zanganeh Mahkam Zanganeh Mahkam Zanganeh
PEO | Duggan [Member] | Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table          
Pay vs Performance Disclosure          
Adjustment to Compensation, Amount $ 0        
PEO | Duggan [Member] | Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested          
Pay vs Performance Disclosure          
Adjustment to Compensation, Amount 0        
PEO | Duggan [Member] | Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year          
Pay vs Performance Disclosure          
Adjustment to Compensation, Amount 0        
PEO | Duggan [Member] | Excess Fair Value for Award Modifications [Member]          
Pay vs Performance Disclosure          
Adjustment to Compensation, Amount 0        
PEO | Zanganeh [Member] | Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table          
Pay vs Performance Disclosure          
Adjustment to Compensation, Amount (245,021,384)        
PEO | Zanganeh [Member] | Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested          
Pay vs Performance Disclosure          
Adjustment to Compensation, Amount (2,717,693)        
PEO | Zanganeh [Member] | Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year          
Pay vs Performance Disclosure          
Adjustment to Compensation, Amount 14,689,022        
PEO | Zanganeh [Member] | Excess Fair Value for Award Modifications [Member]          
Pay vs Performance Disclosure          
Adjustment to Compensation, Amount 220,112,592        
Non-PEO NEO | Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table          
Pay vs Performance Disclosure          
Adjustment to Compensation, Amount (248,101,887)        
Non-PEO NEO | Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested          
Pay vs Performance Disclosure          
Adjustment to Compensation, Amount (3,575,833)        
Non-PEO NEO | Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year          
Pay vs Performance Disclosure          
Adjustment to Compensation, Amount 17,807,935        
Non-PEO NEO | Excess Fair Value for Award Modifications [Member]          
Pay vs Performance Disclosure          
Adjustment to Compensation, Amount $ 222,748,637