0001847903-25-000156 | 10-Q | XBRL Viewer | Centessa Pharmaceuticals PLC

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Organization and Description of Business (Details) - USD ($) $ in Thousands	9 Months Ended	32 Months Ended
	Sep. 30, 2025	Sep. 30, 2025	Dec. 31, 2024	Jan. 27, 2023
Subsidiary, Sale of Stock [Line Items]
Accumulated deficit	$ (1,120,071)	$ (1,120,071)	$ (988,702)
Cash and cash equivalents and short-term investments	$ 349,000	$ 349,000
ATM Program
Subsidiary, Sale of Stock [Line Items]
Sale of stock, consideration receivable (up to)				$ 125,000
Shares sold in offering (in shares)	372,538	4,663,354
Aggregate net proceeds from shares sold	$ 6,100	$ 36,600

- Definition

Amount of accumulated undistributed earnings (deficit).

+ References + Details

Fair Value Measurement

9 Months Ended

Sep. 30, 2025

Fair Value Disclosures [Abstract]

Fair Value Measurement

Fair value is the price that could be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. Fair value determination in accordance with applicable accounting guidance requires that a number of significant judgments be made. Additionally, fair value is used on a nonrecurring basis to evaluate assets for impairment or as required for disclosure purposes by applicable accounting guidance on disclosures about fair value of financial instruments. Depending on the nature of the assets and liabilities, various valuation techniques and assumptions are used when estimating fair value. The carrying amounts of certain of the Company’s financial instruments, including cash, prepaid expenses, tax incentive receivable and accounts payable, are shown at cost, which approximates fair value due to the short-term nature of these instruments.

The Company follows the provisions of FASB ASC Topic 820, Fair Value Measurement, for financial assets and liabilities measured on a recurring basis. The guidance requires fair value measurements be classified and disclosed in one of the following three categories:

Level 1: Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities.

Level 2: Quoted prices in markets that are not active, or inputs which are observable, either directly or indirectly, for substantially the full term of the asset or liabilities.

Level 3: Prices or valuation techniques that require inputs that are both significant to the fair value measurement and unobservable (i.e., supported by little or no market activity).

The following fair value hierarchy table presents information about the Company’s financial assets measured and carried at fair value (amounts in thousands):


	Fair value measurement at reporting date using
	Quoted prices in active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)		Total
September 30, 2025
Assets
Money Market fund	$	28,397	$	—	$	—	$	28,397
U.S. Treasury and government agency securities	72,618		90,581		—		163,199
Corporate debt securities	—		110,295		—		110,295
Commercial paper	—		24,734		—		24,734
Total	$	101,015	$	225,610	$	—	$	326,625


December 31, 2024
Assets
Money Market fund	$	217,515	$	—	$	—	$	217,515
U.S. Treasury securities	171,885		—		—		171,885
Total	$	389,400	$	—	$	—	$	389,400

We classify our investments in available-for-sale U.S. Treasury securities and the money market fund into Level 1 of the ASC Topic 820 hierarchy because fair values represent quoted market prices for identical or comparable instruments. The Company estimates the fair value of its U.S. government agency securities, corporate debt securities and commercial paper by taking into consideration valuations obtained from third-party pricing services. The pricing services utilize industry standard valuation models, including both income and market-based approaches, for which all significant inputs are observable, either directly or indirectly, to estimate fair value. These inputs include reported trades of and broker/dealer quotes on the same or similar securities, issuer credit spreads; benchmark securities; prepayment/default projections based on historical data; and other observable inputs.

The following represents the amortized cost bases and fair values of the Company’s fixed income investments as of September 30, 2025 (amounts in thousands):


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Money Market fund, included in Cash and cash equivalents	$	28,397	$	—	$	—	$	28,397

U.S. Treasury and government agency securities, included in:

Short-term investments	$	128,447	$	44	$	(20)	$	128,471
Long-term investments	34,712		42		(26)		34,728
Total U.S. Treasury and government agency securities	$	163,159	$	86	$	(46)	$	163,199

Corporate debt securities, included in:
Short-term investments	$	42,125	$	75	$	(2)	$	42,198
Long-term investments	67,809		297		(9)		68,097
Total Corporate debt securities	$	109,934	$	372	$	(11)	$	110,295

Commercial paper, included in:

Short-term investments	$	24,726	$	8	$	—	$	24,734
Total Commercial paper	$	24,726	$	8	$	—	$	24,734

In aggregate:
Investments above with no unrealized loss	$	245,157	$	466	$	—	$	245,623
Investments above with unrealized loss	81,059		—		(57)		81,002
Total investments	$	326,216	$	466	$	(57)	$	326,625

At the end of September 30, 2025, the Company held approximately 51 debt securities, of which 15 were in a unrealized loss position as of the end of the period, with an aggregate fair value of $81.0 million. The Company has not recorded any allowance for credit losses as of September 30, 2025 as it believes the decline in fair value below amortized cost is not related to credit losses. These investments in an unrealized loss position were in this position for less than 12 months and there has been no change in the credit risk of such securities during the period. The Company does not intend to sell its investments and it is not more likely than not that the Company will be required to sell the securities before recovery of the amortized cost basis of its debt securities. Securities are evaluated at the end of each reporting period for evidence of the credit-related impairment.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References

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+ Details

Cover - shares	9 Months Ended
Cover - shares	Sep. 30, 2025	Oct. 31, 2025
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2025
Entity Transition Report	false
Entity File Number	001-40445
Entity Registrant Name	CENTESSA PHARMACEUTICALS PLC
Entity Incorporation, State or Country Code	X0
Entity Tax Identification Number	98-1612294
Entity Address, Address Line One	3rd Floor
Entity Address, Address Line Two	1 Ashley Road
Entity Address, Address Line Three	Altrincham
Entity Address, City or Town	Cheshire
Entity Address, Country	GB
Entity Address, Postal Zip Code	WA14 2DT
Country Region	1
City Area Code	(617)
Local Phone Number	468-5770
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		134,447,836
Amendment Flag	false
Document Fiscal Year Focus	2025
Document Fiscal Period Focus	Q3
Entity Central Index Key	0001847903
Current Fiscal Year End Date	--12-31
Ordinary shares
Document Information [Line Items]
Title of 12(b) Security	Ordinary shares, nominal value £0.002 per share
Trading Symbol	CNTA
Security Exchange Name	NASDAQ
American Depositary Shares
Document Information [Line Items]
Title of 12(b) Security	American Depositary Shares, each representing one ordinary share, nominal value £0.002 per share
Trading Symbol	CNTA
Security Exchange Name	NASDAQ

Commitments and Contingencies - Cash Flow, Supplemental Disclosures (Details)	Sep. 30, 2025
Commitments and Contingencies Disclosure [Abstract]
Weighted-average remaining lease term	7 years 3 months 18 days
Weighted-average discount rate	11.97%

Commitments and Contingencies - Balance Sheet Information Related to Leases (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Assets:
Operating lease, right-of-use asset	$ 10,295	$ 11,013
Liabilities:
Current portion of operating lease liabilities	684	602
Operating lease liabilities, net of current portion	7,759	$ 8,286
Total operating lease liabilities	$ 8,443

Debt

9 Months Ended

Sep. 30, 2025

Debt Disclosure [Abstract]

Debt

Debt as of September 30, 2025 and December 31, 2024 (in thousands):


	September 30, 2025		December 31, 2024
Loan and Security Agreement (“LSA”):
Principal amount	$	110,000	$	110,000
End of term charge	5,500		5,500
Unamortized debt issuance costs and unamortized end of term charge	(5,684)		(6,560)
Loan and Security Agreement (carried at amortized cost)	$	109,816	$	108,940
The fair value of LSA, classified as Level 2 under ASC Topic 820, Fair Value Measurement	$	109,038	$	109,450

Future principal payments, including the end of term charge, are as follows (in thousands):


Year ending:	Payments
2025	$	—
2026	—
2027	—
2028	—
2029	115,500
Total principal payments, including End of Term Charge	$	115,500

- Definition

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

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+ Details

Share-based Compensation

9 Months Ended

Sep. 30, 2025

Share-Based Payment Arrangement [Abstract]

Share-based Compensation

Centessa Pharmaceuticals plc Stock Option and Incentive Plan

Remaining shares available for future grants as of September 30, 2025 under the 2021 Stock Option and Incentive Plan (the “2021 Plan”) were 11,454,749.

Share-based Compensation Expense

The Company recorded share-based compensation expense in the following expense categories in the unaudited interim consolidated statements of operations and comprehensive loss (amounts in thousands):


	Three Months Ended September 30, 2025		Three Months Ended September 30, 2024		Nine Months Ended September 30, 2025		Nine Months Ended September 30, 2024
Research and development	$	3,298	$	3,642	$	11,570	$	11,373
General and administrative	3,896		4,811		11,456		13,845
	$	7,194	$	8,453	$	23,026	$	25,218

Share-based compensation expense by award type was as follows included within the unaudited interim consolidated statements of operations and comprehensive loss: (amounts in thousands):


	Three Months Ended September 30, 2025		Three Months Ended September 30, 2024		Nine Months Ended September 30, 2025		Nine Months Ended September 30, 2024
Stock options	$	6,568	$	5,722	$	19,590	$	16,929
Restricted share awards and units	626		2,731		3,436		8,289
	$	7,194	$	8,453	$	23,026	$	25,218

Stock Options

The following table summarizes stock option activity for the nine months ended September 30, 2025:


	Number of Shares	Weighted-Average Exercise Price Per Share		Weighted-Average Remaining Contractual Term	Aggregate Intrinsic Value (in millions)
Balance at January 1, 2025	17,434,119	$	7.77	7.4 years
Granted	5,387,740	$	16.03
Exercised	(1,087,469)	$	6.43
Forfeited	(858,214)	$	10.60
Balance at September 30, 2025	20,876,176	$	9.86	7.1 years	$	300.5
Exercisable at September 30, 2025	12,757,975	$	7.92	6.0 years	$	208.3
Vested and expected to vest at September 30, 2025	20,876,176	$	9.86	7.1 years	$	300.5

The weighted-average grant date fair value of options granted was $11.40 per share for the nine months ended September 30, 2025. As of September 30, 2025, the total unrecognized compensation expense related to unvested stock option awards was $67.1 million, which the Company expects to recognize over a weighted-average period of 3.1 years.

The fair value of each option was estimated on the date of grant under the Black-Scholes option pricing model using the weighted average assumptions in the table below:


	Nine Months Ended September 30, 2025		Nine Months Ended September 30, 2024
Expected term	6.0 years		5.9 years
Expected stock price volatility	79.5	%	76.1	%
Risk-free interest rate	4.3	%	4.0	%
Expected dividend yield	0	%	0	%

Restricted Share Awards and Units

The following table summarizes ordinary share activity related to the restricted stock programs for the nine months ended September 30, 2025:


	Restricted Stock Awards				Restricted Stock Units
	Number of Shares		Weighted-Average Grant Date Fair Value Per Share		Number of Shares		Weighted-Average Grant Date Fair Value Per Share
Unvested at January 1, 2025	86,864		$	20.00	1,510,077		$	6.14
Granted	—		$	—	123,610		$	16.45
Vested	(86,864)		$	20.00	(428,118)		$	5.69
Forfeited	—		$	—	(170,168)		$	6.28
Unvested at September 30, 2025	—		$	—	1,035,401		$	7.53

Unrecognized compensation expense at September 30, 2025 (in thousands)	$	—			$	6,115
Expected weighted average recognition period	0.0 years				2.5 years

Employee Share Purchase Plan

As of September 30, 2025, no shares have been purchased or issued under the 2021 Employee Share Purchase Plan (the “ESPP”) and remaining shares reserved for the ESPP were 2,708,515.

Genmab License Agreement	9 Months Ended
Genmab License Agreement	Sep. 30, 2025
Revenue from Contract with Customer [Abstract]
Genmab License Agreement	Genmab License Agreement Background On February 14, 2025, the Company entered into a license agreement (the “License Agreement”) with Genmab A/S (“Genmab”) pursuant to which the Company granted to Genmab an exclusive worldwide license to leverage its proprietary LockBody technology platform to perform research on up to three undisclosed targets selected during a multi-year research period. Additionally, the License Agreement provides Genmab with the option to obtain an exclusive commercial license for worldwide development and commercialization of products against each of the selected three targets. Genmab will conduct all research and development activities under the License Agreement, which may combine the Company’s LockBody technology with Genmab’s proprietary antibody technologies. The LockBody technology platform is designed to improve the therapeutic index of therapies by allowing the conditional activation of potent cell killing mechanisms in diseased tissue, but not in non-diseased tissue. Under the terms of the License Agreement, the Company received a non-refundable upfront payment of $15.0 million related to the license of the LockBody technology platform. Additionally, the Company may receive, in the future, an aggregate of up to $15.0 million when (and if) Genmab exercises the options to acquire the exclusive commercial licenses as discussed above. Further, the Company is eligible to receive potential payouts of up to $234.0 million in development, regulatory and sales milestones per product, as well as tiered royalties ranging in the mid single-digits on annual global net licensed product sales. The License Agreement includes various representations, warranties, covenants, indemnities, and other customary provisions. Unless earlier terminated in accordance with its terms, the License Agreement will expire upon expiration of the last royalty term for the last licensed product. Genmab may terminate the License Agreement or on a target-by-target basis for convenience upon specified time periods. On a target-by-target basis, if Genmab elects not to exercise its option for an exclusive commercial license for worldwide development and commercialization of products against the applicable target (a “Reserved Target”), then the License Agreement will automatically terminate with respect to such Reserved Target. Subject to the terms and specified exceptions set forth in the License Agreement, either party may terminate the License Agreement for the other party’s uncured material breach or insolvency upon a specified notice period. Accounting Treatment The Company assessed the License Agreement in accordance with ASC 606, Revenue with Contracts from Customers, and concluded that the promises in the License Agreement represent a transaction with a customer. The following promises within the License Agreement were identified: (i) the exclusive license of the Lockbody technology platform and the ability to perform research on up to three targets, (ii) initial and continuing know-how transfer for the Lockbody technology platform, and (iii) participation in a joint steering committee (“JSC”). The promises related to the know-how transfer and JSC participation were determined to be immaterial in the context of the contract as the time commitment and related cost is expected to be inconsequential to the total contract consideration. Accordingly, they were not assessed as performance obligations. Additionally, the Company also evaluated the options to acquire exclusive commercial licenses contained within the License Agreement to determine if they provide Genmab with any material rights. The Company concluded that the options were not issued at a significant and incremental discount and therefore do not provide Genmab with a material right. As such, these options were excluded as performance obligations and will be accounted for when (and if) they are exercised. As a result, the Company determined that the promise to provide the exclusive license constitutes a single performance obligation within the License Agreement. Further, the exclusive license represents functional intellectual property given the Company will not be providing any additional services to Genmab outside of the right to use the licensed intellectual property. Accordingly, the $15.0 million up front payment was recognized as revenue at a point in time during the first quarter of 2025, upon delivery of the exclusive license to Genmab at contract inception. As of September 30, 2025, the Company has constrained all variable consideration related to potential milestone payments associated with the License Agreement given the level of uncertainty associated with their achievement. Accordingly, no revenue relating to these milestones has been recognized.

- Definition

The entire disclosure of revenue from contract with customer to transfer good or service and to transfer nonfinancial asset. Includes, but is not limited to, disaggregation of revenue, credit loss recognized from contract with customer, judgment and change in judgment related to contract with customer, and asset recognized from cost incurred to obtain or fulfill contract with customer. Excludes insurance and lease contracts.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-7

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
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-Name Accounting Standards Codification
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-Paragraph 9
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-URI https://asc.fasb.org/1943274/2147479806/606-10-50-9

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
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-URI https://asc.fasb.org/1943274/2147479806/606-10-50-10

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
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-URI https://asc.fasb.org/1943274/2147479806/606-10-50-15

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
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-Paragraph 12
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-12

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
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-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-12

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
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-Section 50
-Paragraph 12
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
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-Paragraph 12
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Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
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-Name Accounting Standards Codification
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-Paragraph 13
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-URI https://asc.fasb.org/1943274/2147479806/606-10-50-13

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Name Accounting Standards Codification
-Topic 606
-Publisher FASB
-URI https://asc.fasb.org/606/tableOfContent

+ Details

Debt (Tables)

9 Months Ended

Sep. 30, 2025

Debt Disclosure [Abstract]

Schedule of Debt

Debt as of September 30, 2025 and December 31, 2024 (in thousands):


	September 30, 2025		December 31, 2024
Loan and Security Agreement (“LSA”):
Principal amount	$	110,000	$	110,000
End of term charge	5,500		5,500
Unamortized debt issuance costs and unamortized end of term charge	(5,684)		(6,560)
Loan and Security Agreement (carried at amortized cost)	$	109,816	$	108,940
The fair value of LSA, classified as Level 2 under ASC Topic 820, Fair Value Measurement	$	109,038	$	109,450

Schedule of Maturities of Long-Term Debt

Future principal payments, including the end of term charge, are as follows (in thousands):


Year ending:	Payments
2025	$	—
2026	—
2027	—
2028	—
2029	115,500
Total principal payments, including End of Term Charge	$	115,500

Debt - Schedule of Maturities of Long-Term Debt (Details) $ in Thousands	Sep. 30, 2025 USD ($)
Debt Disclosure [Abstract]
2025	$ 0
2026	0
2027	0
2028	0
2029	115,500
Total principal payments, including End of Term Charge	$ 115,500

Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Underwriter Offering	ATM Program	Ordinary Shares	Ordinary Shares Underwriter Offering	Ordinary Shares ATM Program	Additional paid-in capital	Additional paid-in capital Underwriter Offering	Additional paid-in capital ATM Program	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2023				98,774,827
Beginning balance at Dec. 31, 2023	$ 236,244			$ 273			$ 987,423			$ 1,493	$ (752,945)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of ordinary shares, net of issuance costs (in shares)					29,932,626	1,250,000
Issuance of ordinary shares, net of issuance costs		$ 349,980	$ 9,655		$ 76	$ 3		$ 349,904	$ 9,652
Stock option exercises (in shares)				1,054,246
Stock option exercises	6,311			$ 2			6,309
Share-based compensation expense	25,218						25,218
Vesting of ordinary shares (in shares)				1,055,535
Vesting of ordinary shares	0			$ 3			(3)
Shares withheld to pay employee withholding tax on share-based compensation (in shares)				(408,131)
Shares withheld to pay employee withholding tax on share-based compensation	(4,445)						(4,445)
Foreign currency translation adjustments	(498)									(498)
Unrealized gain on available for sale securities, net of tax	2,390									2,390
Reclassification adjustment for realized net gain on available for sale marketable securities included in net loss, net of tax	(1,290)									(1,290)
Net loss	(124,428)										(124,428)
Ending balance (in shares) at Sep. 30, 2024				131,659,103
Ending balance at Sep. 30, 2024	499,137			$ 357			1,374,058			2,095	(877,373)
Beginning balance (in shares) at Jun. 30, 2024				113,177,764
Beginning balance at Jun. 30, 2024	286,965			$ 309			1,119,868			1,595	(834,807)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of ordinary shares, net of issuance costs (in shares)					17,542,372
Issuance of ordinary shares, net of issuance costs		$ 242,708			$ 45			$ 242,663
Stock option exercises (in shares)				751,810
Stock option exercises	4,664			$ 2			4,662
Share-based compensation expense	8,453						8,453
Vesting of ordinary shares (in shares)				292,384
Vesting of ordinary shares	0			$ 1			(1)
Shares withheld to pay employee withholding tax on share-based compensation (in shares)				(105,227)
Shares withheld to pay employee withholding tax on share-based compensation	(1,587)						(1,587)
Foreign currency translation adjustments	(412)									(412)
Unrealized gain on available for sale securities, net of tax	912									912
Net loss	(42,566)										(42,566)
Ending balance (in shares) at Sep. 30, 2024				131,659,103
Ending balance at Sep. 30, 2024	$ 499,137			$ 357			1,374,058			2,095	(877,373)
Beginning balance (in shares) at Dec. 31, 2024	132,631,587			132,631,587
Beginning balance at Dec. 31, 2024	$ 401,545			$ 359			1,385,675			4,213	(988,702)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of ordinary shares, net of issuance costs (in shares)						372,538
Issuance of ordinary shares, net of issuance costs			$ 6,109			$ 1			$ 6,108
Stock option exercises (in shares)	1,087,469			1,087,469
Stock option exercises	$ 6,995			$ 3			6,992
Share-based compensation expense	23,026						23,026
Vesting of ordinary shares (in shares)				514,982
Vesting of ordinary shares	0			$ 1			(1)
Shares withheld to pay employee withholding tax on share-based compensation (in shares)				(185,427)
Shares withheld to pay employee withholding tax on share-based compensation	(3,119)						(3,119)
Foreign currency translation adjustments	855									855
Unrealized gain on available for sale securities, net of tax	319									319
Reclassification adjustment for realized net gain on available for sale marketable securities included in net loss, net of tax	(2,787)
Net loss	$ (131,369)										(131,369)
Ending balance (in shares) at Sep. 30, 2025	134,421,149			134,421,149
Ending balance at Sep. 30, 2025	$ 301,574			$ 364			1,418,681			2,600	(1,120,071)
Beginning balance (in shares) at Jun. 30, 2025				133,913,556
Beginning balance at Jun. 30, 2025	344,919			$ 363			1,408,145			1,591	(1,065,180)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock option exercises (in shares)				495,143
Stock option exercises	3,468			$ 1			3,467
Share-based compensation expense	7,194						7,194
Vesting of ordinary shares (in shares)				19,664
Shares withheld to pay employee withholding tax on share-based compensation (in shares)				(7,214)
Shares withheld to pay employee withholding tax on share-based compensation	(125)						(125)
Foreign currency translation adjustments	691									691
Unrealized gain on available for sale securities, net of tax	318									318
Net loss	$ (54,891)										(54,891)
Ending balance (in shares) at Sep. 30, 2025	134,421,149			134,421,149
Ending balance at Sep. 30, 2025	$ 301,574			$ 364			$ 1,418,681			$ 2,600	$ (1,120,071)

Fair Value Measurement - Schedule of Debt Securities, Fair Value of U.S. Treasury Securities and Money Market Fund (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Debt Securities, Available-for-Sale [Line Items]
Money market fund, included in cash and cash equivalents, amortized cost	$ 50,811	$ 383,221
U.S. Treasury securities, amortized cost	326,216
Investments above with no unrealized loss, amortized cost	245,157
Investments above with unrealized loss, amortized cost	81,059
U.S. Treasury securities, gross unrealized gains	466
Investments above with no unrealized loss, gross unrealized gains	466
U.S. Treasury securities, gross unrealized losses	(57)
Investments above with unrealized loss, gross unrealized losses	(57)
Debt securities, available-for-sale, fair value	326,625
Investments above with no unrealized loss, fair value	245,623
Investments above with unrealized loss, fair value	81,002
Money Market fund
Debt Securities, Available-for-Sale [Line Items]
Money market fund, included in cash and cash equivalents, amortized cost	28,397
Money market fund, included in cash and cash equivalents, fair value	28,397
U.S. Treasury and government agency securities
Debt Securities, Available-for-Sale [Line Items]
U.S. Treasury securities, amortized cost	163,159
U.S. Treasury securities, gross unrealized gains	86
U.S. Treasury securities, gross unrealized losses	(46)
Debt securities, available-for-sale, fair value	163,199
U.S. Treasury and government agency securities \| Short-term investments
Debt Securities, Available-for-Sale [Line Items]
U.S. Treasury securities, amortized cost	128,447
U.S. Treasury securities, gross unrealized gains	44
U.S. Treasury securities, gross unrealized losses	(20)
Debt securities, available-for-sale, fair value	128,471
U.S. Treasury and government agency securities \| Long-term investments
Debt Securities, Available-for-Sale [Line Items]
U.S. Treasury securities, amortized cost	34,712
U.S. Treasury securities, gross unrealized gains	42
U.S. Treasury securities, gross unrealized losses	(26)
Debt securities, available-for-sale, fair value	34,728
Corporate debt securities, included in:
Debt Securities, Available-for-Sale [Line Items]
U.S. Treasury securities, amortized cost	109,934
U.S. Treasury securities, gross unrealized gains	372
U.S. Treasury securities, gross unrealized losses	(11)
Debt securities, available-for-sale, fair value	110,295
Corporate debt securities, included in: \| Short-term investments
Debt Securities, Available-for-Sale [Line Items]
U.S. Treasury securities, amortized cost	42,125
U.S. Treasury securities, gross unrealized gains	75
U.S. Treasury securities, gross unrealized losses	(2)
Debt securities, available-for-sale, fair value	42,198
Corporate debt securities, included in: \| Long-term investments
Debt Securities, Available-for-Sale [Line Items]
U.S. Treasury securities, amortized cost	67,809
U.S. Treasury securities, gross unrealized gains	297
U.S. Treasury securities, gross unrealized losses	(9)
Debt securities, available-for-sale, fair value	68,097
Commercial paper, included in:
Debt Securities, Available-for-Sale [Line Items]
U.S. Treasury securities, amortized cost	24,726
U.S. Treasury securities, gross unrealized gains	8
U.S. Treasury securities, gross unrealized losses	0
Debt securities, available-for-sale, fair value	24,734
Commercial paper, included in: \| Short-term investments
Debt Securities, Available-for-Sale [Line Items]
U.S. Treasury securities, amortized cost	24,726
U.S. Treasury securities, gross unrealized gains	8
U.S. Treasury securities, gross unrealized losses	0
Debt securities, available-for-sale, fair value	$ 24,734

Commitments and Contingencies - Narrative (Details) $ in Millions	Sep. 30, 2025 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Purchase obligation	$ 11.5
Purchase obligation, to be paid, within one year	10.8
Purchase obligation, to be paid, year one through five	$ 0.7

Share-based Compensation - Summary of Share-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Compensation expense recognized	$ 7,194	$ 8,453	$ 23,026	$ 25,218
Stock options
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Compensation expense recognized	6,568	5,722	19,590	16,929
Restricted share awards and units
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Compensation expense recognized	626	2,731	3,436	8,289
Research and development
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Compensation expense recognized	3,298	3,642	11,570	11,373
General and administrative
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Compensation expense recognized	$ 3,896	$ 4,811	$ 11,456	$ 13,845

Organization and Description of Business	9 Months Ended
Organization and Description of Business	Sep. 30, 2025
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Description of Business	Organization and Description of Business Centessa Pharmaceuticals plc (“Centessa” or “the Company”) is a clinical-stage pharmaceutical company that aims to discover, develop and ultimately deliver medicines that are transformational for patients. Centessa was incorporated on October 26, 2020 as a limited liability company under the laws of England and Wales. In connection with the Company’s initial public offering, or IPO, the Company re-registered Centessa Pharmaceuticals Limited as an English public limited company and renamed it as Centessa Pharmaceuticals plc. Risks and Liquidity The Company is subject to risks common to other life science companies in various stages of development including, but not limited to, uncertainty of product development and commercialization, lack of marketing and sales history, development by its competitors of new technological innovations, dependence on key personnel, market acceptance of products, product liability, protection of proprietary technology, ability to raise additional financing and compliance with government regulations in the markets in which the Company is seeking approvals, including U.S. Food and Drug Administration (“FDA”) regulations. If the Company does not successfully advance its programs, into and through human clinical trials and/or enter into collaborations for its programs and commercialize any of its product candidates, it may be unable to produce product revenue or achieve profitability. The Company has incurred losses and negative cash flows from operations since inception and the Company had an accumulated deficit of $1.12 billion as of September 30, 2025. The Company anticipates incurring additional losses until such time, if ever, that it can generate significant sales of the product candidates currently in development. Substantial additional capital will be needed by the Company to fund its operations and to develop its product candidates. The Company entered into a Sales Agreement, dated January 27, 2023, by and between Centessa Pharmaceuticals plc and Leerink Partners LLC (formerly SVB Securities LLC). As sales agent, Leerink Partners LLC will provide for the issuance and sale by the Company of up to $125.0 million of its ordinary shares represented by American Depository Shares (“ADSs”) from time to time in “at-the-market” offerings (“ATM Program”). In the nine months ended September 30, 2025, the Company sold 372,538 ordinary shares under the ATM Program, resulting in net proceeds of $6.1 million, all of which were collected during the first quarter of 2025. Since the inception of the ATM program in 2023, as of September 30, 2025, the Company has sold 4,663,354 ordinary shares under the ATM Program, resulting in net proceeds to us of approximately $36.6 million. The Company expects its existing cash, cash equivalents and investments as of September 30, 2025 of $349.0 million will be sufficient to fund its expected operating expenses and capital expenditure requirements for at least the next twelve months from the date of issuance of these unaudited interim consolidated financial statements. Emerging Growth Company and Smaller Reporting Company status The Company is an emerging growth company, as defined in the JOBS Act. Under the JOBS Act, emerging growth companies can delay the adoption of new or revised accounting standards issued subsequent to the enactment of the JOBS Act until such time as those standards apply to private companies. Other exemptions and reduced reporting requirements under the JOBS Act for emerging growth companies include presentation of only two years of audited financial statements in a registration statement for an initial public offering, an exemption from the requirement to provide an auditor’s report on internal controls over financial reporting pursuant to Section 404 of the Sarbanes-Oxley Act of 2002, as amended, an exemption from any requirement that may be adopted by the Public Company Accounting Oversight Board regarding mandatory audit firm rotation and less extensive disclosure about our executive compensation arrangements. The Company has elected to use the extended transition period for complying with new or revised accounting standards that have different effective dates for public and private companies until the earlier of the date that (i) it is no longer an emerging growth company or (ii) the Company affirmatively and irrevocably opts out of the extended transition period provided in the JOBS Act. The Company will remain an emerging growth company until the earliest of (i) the last day of its first fiscal year in which it has total annual gross revenues of $1.235 billion or more, (ii) the last day of its first fiscal year following the fifth anniversary of the closing of its initial public offering, (iii) the date on which it is deemed to be a “large accelerated filer,” under the rules of the SEC, or (iv) the date on which we have issued more than $1.0 billion in non-convertible debt securities during the prior three-year period. The Company is also a “smaller reporting company” as defined in the Securities Exchange Act of 1934 (the “Exchange Act”). If it is a smaller reporting company at the time we cease to be an emerging growth company, the Company may continue to rely on exemptions from certain disclosure requirements that are available to smaller reporting companies. Specifically, as a smaller reporting company it may choose to present only the two most recent fiscal years of audited financial statements in its Annual Report on Form 10-K and, similar to emerging growth companies, smaller reporting companies have reduced disclosure obligations regarding executive compensation. As of December 31, 2025, the Company will cease to be a “smaller reporting company” (“SRC”) as defined in the Exchange Act. For the first fiscal quarter of 2026, the Company will no longer be permitted to take advantage of scaled disclosure requirements for SRCs. The Company will retain its non-accelerated filer status for its filings due in the fiscal year 2026. The Company is also granted a one-year transition period before it must comply with the auditor attestation requirements of Section 404(b) of the Sarbanes-Oxley Act, and its independent registered public accounting firm must evaluate and report on the effectiveness of internal control over financial reporting.

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	Sep. 30, 2025
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Income Statement [Abstract]
License and other revenue	$ 0	$ 0	$ 15,000	$ 0
Operating expenses:
Research and development	41,563	33,903	117,747	89,370
General and administrative	12,227	12,502	36,473	37,105
Loss from operations	(53,790)	(46,405)	(139,220)	(126,475)
Interest and investment income	3,765	3,340	16,035	9,171
Interest expense	(2,890)	(2,557)	(8,651)	(7,611)
Other non-operating income (expense), net	(1,810)	3,664	2,808	2,281
Loss before income taxes	(54,725)	(41,958)	(129,028)	(122,634)
Income tax expense	166	608	2,341	1,794
Net loss	(54,891)	(42,566)	(131,369)	(124,428)
Other comprehensive (loss) income:
Foreign currency translation adjustment	691	(412)	855	(498)
Unrealized (loss) gain on available for sale marketable securities, net of reclassification adjustment and tax	318	912	(2,468)	1,100
Other comprehensive (loss) income	1,009	500	(1,613)	602
Total comprehensive loss	$ (53,882)	$ (42,066)	$ (132,982)	$ (123,826)
Net loss per ordinary share - basic (in dollars per share)	$ (0.41)	$ (0.37)	$ (0.98)	$ (1.15)
Net loss per ordinary share - diluted (in dollars per share)	$ (0.41)	$ (0.37)	$ (0.98)	$ (1.15)
Weighted average ordinary shares outstanding - basic (in shares)	134,163,492	116,253,902	133,627,043	108,571,742
Weighted average ordinary shares outstanding - diluted (in shares)	134,163,492	116,253,902	133,627,043	108,571,742

Balance Sheet Components - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2024	Sep. 30, 2025
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Research and development expenses	$ 38,063	$ 11,235
Personnel related expenses	9,465	5,949
Professional fees	1,782	1,356
Interest payable	0	850
Operating lease	602	684
Income tax liability	835	55
Other	108	310
Accrued expenses and other current liabilities	50,855	20,439
Property, Plant and Equipment [Line Items]
Restructuring reserve	31,482	93
Accrued contract termination costs	31,500
Contract Termination
Property, Plant and Equipment [Line Items]
Restructuring reserve	30,283	$ 0
Accrued contract termination costs	$ 30,300

Commitments and Contingencies

9 Months Ended

Sep. 30, 2025

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

Commitments

As of September 30, 2025, the Company had non-cancellable commitments for purchase of clinical materials, contract manufacturing, maintenance, and committed funding of up to $11.5 million, of which the Company expects to pay $10.8 million within one year and $0.7 million over one to five years. The amount and timing of these payments vary depending on the rate of progress of development. Future clinical trial expenses have not been included within the purchase commitments because they are generally cancelable at any time upon less than 90 days’ prior written notice.

Leases

The following table provides balance sheet information related to leases as of September 30, 2025 (amounts in thousands):


	September 30, 2025
Assets:
Operating lease, right-of-use asset	$	10,295

Liabilities:
Current portion of operating lease liabilities	$	684
Operating lease liabilities, net of current portion	7,759
Total operating lease liabilities	$	8,443

In calculating the present value of the lease payments, the Company elected to utilize its incremental borrowing rate based on the original term of the lease. The following table summarizes supplemental information related to leases as of September 30, 2025:


	September 30, 2025
Weighted-average remaining lease term	7.3 years
Weighted-average discount rate	11.97	%

The components of the Company’s lease costs are classified on its consolidated statements of operations as follows (amounts in thousands):


	Nine Months Ended September 30, 2025		Nine Months Ended September 30, 2024
Operating lease cost	$	1,498	$	1,498
Variable lease cost	78		11
Short term lease cost	18		4
Sublease income	(263)		(263)
Total operating lease cost	$	1,331	$	1,250

Future lease payments and sublease income under non-cancelable operating leases as of September 30, 2025 were as follows (amounts in thousands):


	Operating Leases		Sublease Income
Year ending:
2025	$	408	$	89
2026	1,667		362
2027	1,700		370
2028	1,734		345
2029	1,769		—
Thereafter	5,521		—
Total	$	12,799	$	1,166
Less: Imputed interest	(4,356)
Present value of lease liabilities	$	8,443
Less: current portion	(684)
Lease liabilities, net of current portion	$	7,759

Contingencies

From time to time, the Company may have certain contingent liabilities that arise in the ordinary course of its business activities. The Company accrues a liability for such matters when it is probable that future expenditures will be made, and such expenditures can be reasonably estimated.

Segment Information

9 Months Ended

Sep. 30, 2025

Segment Reporting [Abstract]

Segment Information

Centessa Pharmaceuticals plc is a clinical-stage pharmaceutical company with a mission to discover, develop and ultimately deliver medicines that are transformational for patients. The Company’s ability to generate recurring product revenue and to become profitable will depend upon the ability to successfully develop, obtain regulatory approval and commercialize any current and future product candidates.

The Company manages the business as one segment. Its operating results are regularly reviewed by the Company’s Chief Executive Officer, who is the chief operating decision-maker (“CODM”), based on available financial information prepared on a consolidated basis. The CODM evaluates its performance based primarily on research and development efforts and the results of clinical trials. The CODM also utilizes the Company’s long-range plan as a strategic tool to allocate resources according to the Company’s strategic objectives. The consolidated net loss is used to monitor budget versus actual results in assessing segment performance and the allocation of resources. Assets provided to the CODM are consistent with those reported on the Consolidated Balance Sheets with particular emphasis on the Company’s available liquidity, including its cash, cash equivalents and investments.

The following table presents reportable segment loss, including significant expenses regularly provided to the CODM, attributable to the Company’s reportable segment for the nine months ended September 30, 2025 and September 30, 2024 (in thousands):


	Three Months Ended September 30, 2025		Three Months Ended September 30, 2024		Nine Months Ended September 30, 2025		Nine Months Ended September 30, 2024
License and other revenue	$	—	$	—	$	15,000	$	—
Less:
OX2R agonist program expenses	(35,562)		(11,744)		(88,336)		(26,696)
LockBody program expenses	(3,441)		(2,815)		(8,624)		(9,081)
Discontinued R&D program expenses	585		(16,165)		(3,524)		(44,784)
Other R&D expenses:
Personnel expenses¹	(7,370)		(4,393)		(19,749)		(14,893)
Research tax incentives	9,321		5,500		18,055		18,895
Other preclinical and clinical development expenses	(1,798)		(644)		(3,999)		(1,438)
General and administrative expenses¹	(8,331)		(7,691)		(25,017)		(23,260)
Share-based compensation	(7,194)		(8,453)		(23,026)		(25,218)
Interest and investment income	3,765		3,340		16,035		9,171
Interest expense	(2,890)		(2,557)		(8,651)		(7,611)
Other segment items²	(1,810)		3,664		2,808		2,281
Income tax expense	(166)		(608)		(2,341)		(1,794)
Consolidated net loss	$	(54,891)	$	(42,566)	$	(131,369)	$	(124,428)

¹ Excludes share-based compensation
² Other segment items includes non-operating income (expenses), net

- Definition

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

+ References

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+ Details

Genmab License Agreement (Details) - Genmab A/S - License $ in Millions	Feb. 14, 2025 USD ($) target license	Mar. 31, 2025 USD ($)
Disaggregation of Revenue [Line Items]
Maximum number of undisclosed targets to research products \| target	3
Maximum number of commercial licenses for worldwide development and commercialization of products \| license	3
Upfront payment	$ 15.0	$ 15.0
Maximum additional potential option exercise fee	15.0
Potential additional development and sales milestone	$ 234.0

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

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+ Details

Program Termination (Tables)

9 Months Ended

Sep. 30, 2025

Restructuring and Related Activities [Abstract]

Restructuring and Related Costs

The following table provides a roll-forward of the program termination liability as of September 30, 2025 (in thousands):


	Contract Termination		Severance-Related		Total
Balance as of January 1, 2025	$	30,283	$	1,199	$	31,482
Cash payments	(27,186)		(1,106)		(28,292)
Reversal of charge	(3,395)		—		(3,395)
Foreign currency translation changes	298		—		298
Balance as of September 30, 2025	$	—	$	93	$	93

Segment Information (Details) $ in Thousands	3 Months Ended		9 Months Ended
Segment Information (Details) $ in Thousands	Sep. 30, 2025 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2025 USD ($) segment	Sep. 30, 2024 USD ($)
Segment Reporting [Abstract]
Number of operating segments \| segment			1
Segment Reporting, Asset Reconciling Item [Line Items]
License and other revenue	$ 0	$ 0	$ 15,000	$ 0
Other R&D expenses:
General and administrative expenses	(12,227)	(12,502)	(36,473)	(37,105)
Share-based compensation	7,194	8,453	23,026	25,218
Interest and investment income	3,765	3,340	16,035	9,171
Interest expense	(2,890)	(2,557)	(8,651)	(7,611)
Income tax expense	(166)	(608)	(2,341)	(1,794)
Consolidated net loss	(54,891)	(42,566)	(131,369)	(124,428)
Reportable Segment
Segment Reporting, Asset Reconciling Item [Line Items]
License and other revenue	0	0	15,000	0
Less:
OX2R agonist program expenses	(35,562)	(11,744)	(88,336)	(26,696)
LockBody program expenses	(3,441)	(2,815)	(8,624)	(9,081)
Discontinued R&D program expenses	585	(16,165)	(3,524)	(44,784)
Other R&D expenses:
Personnel expenses	(7,370)	(4,393)	(19,749)	(14,893)
Research tax incentives	9,321	5,500	18,055	18,895
Other preclinical and clinical development expenses	(1,798)	(644)	(3,999)	(1,438)
General and administrative expenses	(8,331)	(7,691)	(25,017)	(23,260)
Share-based compensation	(7,194)	(8,453)	(23,026)	(25,218)
Interest and investment income	3,765	3,340	16,035	9,171
Interest expense	(2,890)	(2,557)	(8,651)	(7,611)
Other segment items	(1,810)	3,664	2,808	2,281
Income tax expense	(166)	(608)	(2,341)	(1,794)
Consolidated net loss	$ (54,891)	$ (42,566)	$ (131,369)	$ (124,428)

Commitments and Contingencies - Components of Lease Expense (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Operating lease cost	$ 1,498	$ 1,498
Variable lease cost	78	11
Short term lease cost	18	4
Sublease income	(263)	(263)
Total operating lease cost	$ 1,331	$ 1,250

Balance Sheet Components - Reconciliation of Changes, Net of Applicable Income Taxes (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 401,545	$ 236,244
Reclassification adjustments	(2,787)	(1,290)
Ending balance	301,574	499,137
Foreign currency translation adjustment:
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	1,426	203
Reclassification adjustments	855	(498)
Ending balance	2,281	(295)
Unrealized gain on available for sale securities:
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	2,787	1,290
Unrealized holding gain on available for sale securities during period, net of tax of $0.1 million in 2025 and $0.7 million in 2024	319	2,390
Reclassification adjustments	(2,787)	(1,290)
Ending balance	319	2,390
Unrealized holding gain on available for sale securities during period, tax	100	700
Reclassification adjustment for realized net gain on available for sale marketable securities included in net loss, tax benefit	$ (800)	$ (400)

- Definition

Amount of equity (deficit) attributable to parent. Excludes temporary equity and equity attributable to noncontrolling interest.

+ References

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+ Details

Share-based Compensation - Summary of Restricted Stock and Restricted Stock Unit, Activity (Details) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2025 USD ($) $ / shares shares
Restricted Stock Awards
Number of Shares
Unvested beginning balance (in shares) \| shares	86,864
Granted (in shares) \| shares	0
Vested (in shares) \| shares	(86,864)
Forfeited (in shares) \| shares	0
Unvested ending balance (in shares) \| shares	0
Unrecognized compensation expense excluding options \| $	$ 0
Expected weighted average recognition period	0 years
Weighted-Average Grant Date Fair Value Per Share
Unvested beginning balance (in dollars per share) \| $ / shares	$ 20.00
Granted (in dollars per share) \| $ / shares	0
Vested (in dollars per share) \| $ / shares	20.00
Forfeited (in dollars per share) \| $ / shares	0
Unvested ending balance (in dollars per share) \| $ / shares	$ 0
Restricted Stock Units
Number of Shares
Unvested beginning balance (in shares) \| shares	1,510,077
Granted (in shares) \| shares	123,610
Vested (in shares) \| shares	(428,118)
Forfeited (in shares) \| shares	(170,168)
Unvested ending balance (in shares) \| shares	1,035,401
Unrecognized compensation expense excluding options \| $	$ 6,115
Expected weighted average recognition period	2 years 6 months
Weighted-Average Grant Date Fair Value Per Share
Unvested beginning balance (in dollars per share) \| $ / shares	$ 6.14
Granted (in dollars per share) \| $ / shares	16.45
Vested (in dollars per share) \| $ / shares	5.69
Forfeited (in dollars per share) \| $ / shares	6.28
Unvested ending balance (in dollars per share) \| $ / shares	$ 7.53

Share-based Compensation (Tables)

9 Months Ended

Sep. 30, 2025

Share-Based Payment Arrangement [Abstract]

Schedule of Share-based Compensation Expense

The Company recorded share-based compensation expense in the following expense categories in the unaudited interim consolidated statements of operations and comprehensive loss (amounts in thousands):


	Three Months Ended September 30, 2025		Three Months Ended September 30, 2024		Nine Months Ended September 30, 2025		Nine Months Ended September 30, 2024
Research and development	$	3,298	$	3,642	$	11,570	$	11,373
General and administrative	3,896		4,811		11,456		13,845
	$	7,194	$	8,453	$	23,026	$	25,218

Share-based compensation expense by award type was as follows included within the unaudited interim consolidated statements of operations and comprehensive loss: (amounts in thousands):


	Three Months Ended September 30, 2025		Three Months Ended September 30, 2024		Nine Months Ended September 30, 2025		Nine Months Ended September 30, 2024
Stock options	$	6,568	$	5,722	$	19,590	$	16,929
Restricted share awards and units	626		2,731		3,436		8,289
	$	7,194	$	8,453	$	23,026	$	25,218

Schedule of Stock Option Activity

The following table summarizes stock option activity for the nine months ended September 30, 2025:


	Number of Shares	Weighted-Average Exercise Price Per Share		Weighted-Average Remaining Contractual Term	Aggregate Intrinsic Value (in millions)
Balance at January 1, 2025	17,434,119	$	7.77	7.4 years
Granted	5,387,740	$	16.03
Exercised	(1,087,469)	$	6.43
Forfeited	(858,214)	$	10.60
Balance at September 30, 2025	20,876,176	$	9.86	7.1 years	$	300.5
Exercisable at September 30, 2025	12,757,975	$	7.92	6.0 years	$	208.3
Vested and expected to vest at September 30, 2025	20,876,176	$	9.86	7.1 years	$	300.5

Schedule of Assumptions Used to Estimate Fair Value of Stock Option Awards

The fair value of each option was estimated on the date of grant under the Black-Scholes option pricing model using the weighted average assumptions in the table below:


	Nine Months Ended September 30, 2025		Nine Months Ended September 30, 2024
Expected term	6.0 years		5.9 years
Expected stock price volatility	79.5	%	76.1	%
Risk-free interest rate	4.3	%	4.0	%
Expected dividend yield	0	%	0	%

Schedule of Replacement Equity Award Activity

The following table summarizes ordinary share activity related to the restricted stock programs for the nine months ended September 30, 2025:


	Restricted Stock Awards				Restricted Stock Units
	Number of Shares		Weighted-Average Grant Date Fair Value Per Share		Number of Shares		Weighted-Average Grant Date Fair Value Per Share
Unvested at January 1, 2025	86,864		$	20.00	1,510,077		$	6.14
Granted	—		$	—	123,610		$	16.45
Vested	(86,864)		$	20.00	(428,118)		$	5.69
Forfeited	—		$	—	(170,168)		$	6.28
Unvested at September 30, 2025	—		$	—	1,035,401		$	7.53

Unrecognized compensation expense at September 30, 2025 (in thousands)	$	—			$	6,115
Expected weighted average recognition period	0.0 years				2.5 years

Share-based Compensation - Summary of Stock Option Activity (Details) $ / shares in Units, $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2025 USD ($) $ / shares shares	Dec. 31, 2024 $ / shares shares
Number of Shares
Beginning balance (in shares) \| shares	17,434,119
Granted (in shares) \| shares	5,387,740
Exercised (in shares) \| shares	(1,087,469)
Forfeited (in shares) \| shares	(858,214)
Ending balance (in shares) \| shares	20,876,176	17,434,119
Exercisable at end of period (in shares) \| shares	12,757,975
Vested and expected to vest at end of period (in shares) \| shares	20,876,176
Weighted-Average Exercise Price Per Share
Beginning balance (in dollars per share) \| $ / shares	$ 7.77
Granted (in dollars per share) \| $ / shares	16.03
Exercised (in dollars per share) \| $ / shares	6.43
Forfeited (in dollars per share) \| $ / shares	10.60
Ending balance (in dollars per share) \| $ / shares	9.86	$ 7.77
Exercisable at end of period (in dollars per share) \| $ / shares	7.92
Vested and expected to vest at end of period (in dollars per share) \| $ / shares	$ 9.86
Weighted-Average Remaining Contractual Term
Options outstanding, weighted-average remaining contractual term	7 years 1 month 6 days	7 years 4 months 24 days
Options exercisable, weighted-average remaining contractual term	6 years
Options vested and expected to vest at end of period, weighted-average remaining contractual term	7 years 1 month 6 days
Aggregate Intrinsic Value (in millions)
Aggregate intrinsic value of options \| $	$ 300.5
Aggregate intrinsic value of exercisable \| $	$ 208.3

Summary of Significant Accounting Policies (Details) - shares	9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted weighted-average ordinary shares outstanding (in shares)	21,911,577	20,499,338
Unvested ordinary shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted weighted-average ordinary shares outstanding (in shares)	0	140,454
Restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted weighted-average ordinary shares outstanding (in shares)	1,035,401	1,833,984
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted weighted-average ordinary shares outstanding (in shares)	20,876,176	18,524,900

Fair Value Measurement - Narrative (Details)	9 Months Ended
Fair Value Measurement - Narrative (Details)	Sep. 30, 2025 USD ($) security position
Fair Value Disclosures [Abstract]
Number of debt securities \| security	51
Number of debt securities, loss position \| position	15
Investments above with unrealized loss, fair value	$ 81,002,000
Allowance for credit loss	$ 0

Segment Information (Tables)

9 Months Ended

Sep. 30, 2025

Segment Reporting [Abstract]

Schedule of Segment Reporting Information, by Segment


	Three Months Ended September 30, 2025		Three Months Ended September 30, 2024		Nine Months Ended September 30, 2025		Nine Months Ended September 30, 2024
License and other revenue	$	—	$	—	$	15,000	$	—
Less:
OX2R agonist program expenses	(35,562)		(11,744)		(88,336)		(26,696)
LockBody program expenses	(3,441)		(2,815)		(8,624)		(9,081)
Discontinued R&D program expenses	585		(16,165)		(3,524)		(44,784)
Other R&D expenses:
Personnel expenses¹	(7,370)		(4,393)		(19,749)		(14,893)
Research tax incentives	9,321		5,500		18,055		18,895
Other preclinical and clinical development expenses	(1,798)		(644)		(3,999)		(1,438)
General and administrative expenses¹	(8,331)		(7,691)		(25,017)		(23,260)
Share-based compensation	(7,194)		(8,453)		(23,026)		(25,218)
Interest and investment income	3,765		3,340		16,035		9,171
Interest expense	(2,890)		(2,557)		(8,651)		(7,611)
Other segment items²	(1,810)		3,664		2,808		2,281
Income tax expense	(166)		(608)		(2,341)		(1,794)
Consolidated net loss	$	(54,891)	$	(42,566)	$	(131,369)	$	(124,428)

¹ Excludes share-based compensation
² Other segment items includes non-operating income (expenses), net

Balance Sheet Components (Tables)

9 Months Ended

Sep. 30, 2025

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Schedule of Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consist of the following (amounts in thousands):


	September 30, 2025		December 31, 2024
Research and development expenses	$	5,230	$	6,314
Interest receivable	1,932		287
Value added tax receivable	1,160		1,528
Insurance related expenses	1,259		840
Other	2,759		1,495
	$	12,340	$	10,464

Schedule of Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consist of the following (amounts in thousands):


	September 30, 2025		December 31, 2024
Research and development expenses*	$	11,235	$	38,063
Personnel related expenses	5,949		9,465
Professional fees	1,356		1,782
Interest payable	850		—
Operating lease	684		602
Income tax liability	55		835
Other	310		108
	$	20,439	$	50,855
∗Includes accrued contract termination costs of $30.3 million as of December 31, 2024 which was fully extinguished as of September 30, 2025. See Note 8.

Schedule of Property and Equipment, Net

Property and equipment, net consisted of the following (amounts in thousands):


	September 30, 2025		December 31, 2024
Computer equipment	$	1,139	$	768
Office furniture	724		724
Other	43		43
Property and equipment, at cost	1,906		1,535
Less: Accumulated depreciation	(1,012)		(791)
Property and equipment, net	$	894	$	744

Schedule of Reconciliation of Changes, Net of Applicable Income Taxes

The following table provides a reconciliation of changes, net of applicable income taxes, in other accumulated comprehensive income (amounts in thousands):


	Nine Months Ended September 30, 2025		Nine Months Ended September 30, 2024
Foreign currency translation adjustment:
Beginning balance	$	1,426	$	203
Foreign currency translation adjustment during period	855		(498)
Ending balance	$	2,281	$	(295)

Unrealized gain on available for sale securities:
Beginning balance	$	2,787	$	1,290
Unrealized holding gain on available for sale securities during period, net of tax of $0.1 million in 2025 and $0.7 million in 2024	319		2,390
Reclassification adjustment for realized net gain on available for sale marketable securities included in net loss, net of tax of $0.8 million in 2025 and $0.4 million in 2024	(2,787)		(1,290)
Ending balance	$	319	$	2,390

Commitments and Contingencies (Tables)

9 Months Ended

Sep. 30, 2025

Commitments and Contingencies Disclosure [Abstract]

Schedule of Balance Sheet Information Related to Leases

The following table provides balance sheet information related to leases as of September 30, 2025 (amounts in thousands):


	September 30, 2025
Assets:
Operating lease, right-of-use asset	$	10,295

Liabilities:
Current portion of operating lease liabilities	$	684
Operating lease liabilities, net of current portion	7,759
Total operating lease liabilities	$	8,443

Schedule of Lease, Cost

The following table summarizes supplemental information related to leases as of September 30, 2025:


	September 30, 2025
Weighted-average remaining lease term	7.3 years
Weighted-average discount rate	11.97	%

The components of the Company’s lease costs are classified on its consolidated statements of operations as follows (amounts in thousands):


	Nine Months Ended September 30, 2025		Nine Months Ended September 30, 2024
Operating lease cost	$	1,498	$	1,498
Variable lease cost	78		11
Short term lease cost	18		4
Sublease income	(263)		(263)
Total operating lease cost	$	1,331	$	1,250

Schedule of Lessee, Operating Lease, Liability, Maturity

Future lease payments and sublease income under non-cancelable operating leases as of September 30, 2025 were as follows (amounts in thousands):


	Operating Leases		Sublease Income
Year ending:
2025	$	408	$	89
2026	1,667		362
2027	1,700		370
2028	1,734		345
2029	1,769		—
Thereafter	5,521		—
Total	$	12,799	$	1,166
Less: Imputed interest	(4,356)
Present value of lease liabilities	$	8,443
Less: current portion	(684)
Lease liabilities, net of current portion	$	7,759

Schedule of Lessor, Operating Lease, Liability, Maturity

Future lease payments and sublease income under non-cancelable operating leases as of September 30, 2025 were as follows (amounts in thousands):


	Operating Leases		Sublease Income
Year ending:
2025	$	408	$	89
2026	1,667		362
2027	1,700		370
2028	1,734		345
2029	1,769		—
Thereafter	5,521		—
Total	$	12,799	$	1,166
Less: Imputed interest	(4,356)
Present value of lease liabilities	$	8,443
Less: current portion	(684)
Lease liabilities, net of current portion	$	7,759

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Cash flows from operating activities:
Net loss	$ (131,369)	$ (124,428)
Adjustments to reconcile net loss to net cash used in operating activities:
Share-based compensation expense	23,026	25,218
Depreciation and amortization	680	712
Amortization of discount of marketable securities	(2,249)	0
Amortization of debt issuance costs and exit fee of long-term debt	876	0
Change in deferred taxes	2,276	2,255
Changes in operating assets and liabilities:
Tax incentive receivable	(3,535)	5,494
Prepaid expenses and other assets	(1,910)	5,730
Operating leases, net	191	225
Accounts payable	1,362	(4,728)
Accrued expenses and other liabilities	(27,358)	(9,963)
Other, net	0	230
Net cash used in operating activities	(138,010)	(99,255)
Cash flows from investing activities:
Purchases of investments in marketable securities	(426,049)	(140,533)
Proceeds from redemption of investments in marketable securities	226,012	146,834
Purchases of property and equipment	(360)	(34)
Net cash (used in) provided by investing activities	(200,397)	6,267
Cash flows from financing activities:
Proceeds from option exercises	7,030	5,885
Payment of employee withholding taxes related to withheld shares for stock based compensation plans	(4,615)	(3,731)
Other, net	(396)	0
Net cash provided by financing activities	8,128	361,789
Effect of exchange rate on cash and cash equivalents	(2,131)	(1,805)
Net decrease in cash and cash equivalents	(332,410)	266,996
Cash and cash equivalents at beginning of period	383,221	128,030
Cash and cash equivalents at end of period	50,811	395,026
Supplemental disclosure:
Interest paid	6,925	7,611
Income taxes paid	1,103	11
Operating lease payments reducing operating lease liabilities	1,225	1,201
Underwriter Offering
Cash flows from financing activities:
Proceeds from issuance of shares under ATM program, net of issuance costs	0	349,980
ATM Program
Cash flows from financing activities:
Proceeds from issuance of shares under ATM program, net of issuance costs	$ 6,109	$ 9,655

Consolidated Balance Sheets (Parenthetical) - £ / shares	Sep. 30, 2025	Dec. 31, 2024
Statement of Financial Position [Abstract]
Ordinary shares, nominal value (in pound sterling per share)	£ 0.002	£ 0.002
Ordinary shares, shares authorized (in shares)	222,480,776	184,469,623
Ordinary shares, shares issued (in shares)	134,421,149	132,631,587
Ordinary shares, shares outstanding (in shares)	134,421,149	132,631,587

Summary of Significant Accounting Policies (Policies)	9 Months Ended
Summary of Significant Accounting Policies (Policies)	Sep. 30, 2025
Accounting Policies [Abstract]
Basis of Presentation and Consolidation	Basis of Presentation and Consolidation The accompanying unaudited interim consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). Any reference in these notes to applicable guidance is meant to refer to GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASUs”) promulgated by the Financial Accounting Standards Board (“FASB”). In the opinion of management, the accompanying unaudited interim consolidated financial statements include all normal and recurring adjustments (which consist primarily of accruals, estimates and assumptions that impact the financial statements) considered necessary to present fairly: •the Company’s financial position as of September 30, 2025 and as of December 31, 2024; •the Company’s results of operations for the three and nine months ended September 30, 2025 and September 30, 2024; and •the Company’s cash flows for the nine months ended September 30, 2025 and September 30, 2024. Operating results for the Company for the three and nine months ended September 30, 2025 are not necessarily indicative of the results that may be expected for the full year. The unaudited interim consolidated financial statements presented herein do not contain all of the required disclosures under U.S. GAAP for annual financial statements. Notes to the financial statements which would substantially duplicate the disclosure contained in the audited financial statements for fiscal 2024 as reported in the 2024 Annual Report have been omitted. Therefore, these unaudited interim consolidated financial statements should be read in conjunction with the annual audited consolidated financial statements and related notes for Centessa Pharmaceuticals plc found in the Form 10-K for the year ended December 31, 2024 filed with the SEC. The Company’s unaudited interim consolidated financial statements include the accounts of Centessa Pharmaceuticals plc, and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation.
Investments in Marketable Securities	Investments in Marketable Securities The Company invests its excess cash in money market funds, U.S. Treasury securities, U.S. government agency securities, corporate debt securities and commercial paper. The Company’s investment policy limits investments to money market funds, certain types of debt securities issued by the U.S. Government and its agencies, corporate notes and commercial paper, and places restrictions on the credit ratings, maturities and concentration by type and issuer. Securities with original maturities of three months or less when purchased are included in cash and cash equivalents. We consider investments with original maturities greater than three months and remaining maturities less than one year to be short-term investments, while remaining maturities greater than one year are classified as long-term investments. As of September 30, 2025, investments in U.S. government Treasury and agency securities, corporate notes and commercial paper were classified as available-for-sale securities, which are recorded at fair value. Unrealized holding gains and losses on available-for-sale securities are reported net of related income taxes in accumulated other comprehensive income until realized. Purchase premiums and discounts are amortized to interest income over the terms of the related securities.
Reclassifications	Reclassifications Certain amounts in the prior period financial statements have been reclassified to conform to the presentation of the current period financial statements. These reclassifications had no effect on previously reported net loss or comprehensive loss.
Use of Estimates	Use of Estimates The preparation of unaudited interim consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the unaudited interim consolidated financial statements and the reported amounts of expenses during the reporting period. Actual results could differ from those estimates. Estimates and assumptions are periodically reviewed and the effects of revisions are reflected in the unaudited interim consolidated financial statements in the period they are determined to be necessary. On an ongoing basis, an evaluation of estimates and judgments are required, including those related to accrued and prepaid research and development expenses, share-based compensation expense and tax related matters. Estimates are based on historical experience, known trends and events, and various other factors that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Changes in estimates are recorded in the period in which they become known. Actual results may differ from these estimates under different assumptions or conditions.
License and other revenue	License and other revenue The Company recognizes revenues from collaboration, license or other research or sale arrangements when or as performance obligations are satisfied. For milestone payments, the Company assesses, at contract inception, whether the milestones are considered probable of being achieved. If it is probable that a significant revenue reversal will occur, the Company will not record revenue until the uncertainty has been resolved. Milestone payments that are contingent upon regulatory approval are not considered probable until the approvals are obtained as it is outside of the control of the Company. If it is probable that significant revenue reversal will not occur, the Company will estimate the milestone payments using the most likely amount method. The Company reassesses the milestones each reporting period to determine the probability of achievement. Any potential consideration received in the form of royalty or sales-based milestones will be recorded when the customer’s subsequent sales or usages occur.

- Definition

Disclosure of accounting policy for investment in financial asset.

+ References + Details

- Definition

Disclosure of accounting policy for revenue from contract with customer.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
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-Name Accounting Standards Codification
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- Definition

Disclosure of accounting policy for the use of estimates in the preparation of financial statements in conformity with generally accepted accounting principles.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
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+ Details

Program Termination

9 Months Ended

Sep. 30, 2025

Restructuring and Related Activities [Abstract]

Program Termination

On November 12, 2024, the Company announced the discontinuation of the global clinical development program for SerpinPC, a novel inhibitor of activated protein C (APC) that was being progressed for the treatment of hemophilia B. The strategic decision was made to prioritize capital towards the development of our growing OX2R agonist franchise based on the

strength of the interim Phase 1 data for ORX750, coupled with the outcome of a planned interim analysis of Part 1 of the PRESent-2 study of SerpinPC, which was evaluated in the context of the evolving treatment and market landscape for hemophilia B, including the recent FDA approval of a competing product.

In the fourth quarter of 2024, as a result of the discontinuation of the program, we incurred a one-time charge of $31.5 million, consisting of contract termination costs of $30.3 million and employee severance related costs of $1.2 million, which was recorded within research and development expenses. The contract termination costs related to firm commitments for the manufacture of registrational materials and other costs. The contract termination and employee severance costs associated with this program discontinuation were predominately accrued as of December 31, 2024. The Company expects the remaining balance associated with employee severance-related costs will be fully extinguished by the end of December 2025.

The following table provides a roll-forward of the program termination liability as of September 30, 2025 (in thousands):


	Contract Termination		Severance-Related		Total
Balance as of January 1, 2025	$	30,283	$	1,199	$	31,482
Cash payments	(27,186)		(1,106)		(28,292)
Reversal of charge	(3,395)		—		(3,395)
Foreign currency translation changes	298		—		298
Balance as of September 30, 2025	$	—	$	93	$	93

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Current assets:
Cash and cash equivalents	$ 50,811	$ 383,221
Short-term investments	195,403	98,956
Tax incentive receivable	49,121	43,768
Prepaid expenses and other current assets	12,340	10,464
Total current assets	307,675	536,409
Long-term investments	102,825	0
Property and equipment, net	894	744
Operating lease right-of-use assets	10,295	11,013
Deferred tax asset	25,022	26,586
Other non-current assets	1,589	2,046
Total assets	448,300	576,798
Current liabilities:
Accounts payable	8,683	7,143
Accrued expenses and other current liabilities	20,439	50,855
Total current liabilities	29,122	57,998
Long term debt	109,816	108,940
Operating lease liabilities	7,759	8,286
Other non-current liabilities	29	29
Total liabilities	146,726	175,253
Commitments and contingencies (Note 7)
Shareholders’ equity:
Ordinary shares: £0.002 nominal value: 222,480,776 shares authorized, 134,421,149 issued and outstanding at September 30, 2025: 184,469,623 shares authorized, 132,631,587 issued and outstanding at December 31, 2024	364	359
Additional paid-in capital	1,418,681	1,385,675
Accumulated other comprehensive income	2,600	4,213
Accumulated deficit	(1,120,071)	(988,702)
Total shareholders’ equity	301,574	401,545
Total liabilities and shareholders' equity	$ 448,300	$ 576,798

Share-based Compensation - Schedule of Assumptions Used to Estimate Fair Value of Stock Option Awards (Details) - Stock options	9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term	6 years	5 years 10 months 24 days
Expected stock price volatility	79.50%	76.10%
Risk-free interest rate	4.30%	4.00%
Expected dividend yield	0.00%	0.00%

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

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+ Details

Program Termination - Schedule of Roll-Forward of the Program Termination Liability (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2025 USD ($)
Restructuring Reserve [Roll Forward]
Balance as of January 1, 2025	$ 31,482
Cash payments	(28,292)
Reversal of charge	(3,395)
Foreign currency translation changes	298
Balance as of September 30, 2025	93
Contract Termination
Restructuring Reserve [Roll Forward]
Balance as of January 1, 2025	30,283
Cash payments	(27,186)
Reversal of charge	(3,395)
Foreign currency translation changes	298
Balance as of September 30, 2025	0
Severance-Related
Restructuring Reserve [Roll Forward]
Balance as of January 1, 2025	1,199
Cash payments	(1,106)
Reversal of charge	0
Foreign currency translation changes	0
Balance as of September 30, 2025	$ 93

Balance Sheet Components

9 Months Ended

Sep. 30, 2025

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Balance Sheet Components

Prepaid expenses and other current assets consist of the following (amounts in thousands):


	September 30, 2025		December 31, 2024
Research and development expenses	$	5,230	$	6,314
Interest receivable	1,932		287
Value added tax receivable	1,160		1,528
Insurance related expenses	1,259		840
Other	2,759		1,495
	$	12,340	$	10,464

Accrued expenses and other current liabilities consist of the following (amounts in thousands):


	September 30, 2025		December 31, 2024
Research and development expenses*	$	11,235	$	38,063
Personnel related expenses	5,949		9,465
Professional fees	1,356		1,782
Interest payable	850		—
Operating lease	684		602
Income tax liability	55		835
Other	310		108
	$	20,439	$	50,855
∗Includes accrued contract termination costs of $30.3 million as of December 31, 2024 which was fully extinguished as of September 30, 2025. See Note 8.

Property and equipment, net consisted of the following (amounts in thousands):


	September 30, 2025		December 31, 2024
Computer equipment	$	1,139	$	768
Office furniture	724		724
Other	43		43
Property and equipment, at cost	1,906		1,535
Less: Accumulated depreciation	(1,012)		(791)
Property and equipment, net	$	894	$	744

The following table provides a reconciliation of changes, net of applicable income taxes, in other accumulated comprehensive income (amounts in thousands):


	Nine Months Ended September 30, 2025		Nine Months Ended September 30, 2024
Foreign currency translation adjustment:
Beginning balance	$	1,426	$	203
Foreign currency translation adjustment during period	855		(498)
Ending balance	$	2,281	$	(295)

Unrealized gain on available for sale securities:
Beginning balance	$	2,787	$	1,290
Unrealized holding gain on available for sale securities during period, net of tax of $0.1 million in 2025 and $0.7 million in 2024	319		2,390
Reclassification adjustment for realized net gain on available for sale marketable securities included in net loss, net of tax of $0.8 million in 2025 and $0.4 million in 2024	(2,787)		(1,290)
Ending balance	$	319	$	2,390

Summary of Significant Accounting Policies

9 Months Ended

Sep. 30, 2025

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

The accompanying unaudited interim consolidated financial statements should be read in conjunction with the annual audited consolidated financial statements of Centessa Pharmaceuticals plc and related notes which can be found in our Annual Report on Form 10-K for the year ended December 31, 2024 (the “2024 Annual Report”). The Summary of Significant Accounting Policies included in the Company’s annual financial statements have not materially changed, except as set forth below.

Basis of Presentation and Consolidation

The accompanying unaudited interim consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). Any reference in these notes to applicable guidance is meant to refer to GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASUs”) promulgated by the Financial Accounting Standards Board (“FASB”).

In the opinion of management, the accompanying unaudited interim consolidated financial statements include all normal and recurring adjustments (which consist primarily of accruals, estimates and assumptions that impact the financial statements) considered necessary to present fairly:

•the Company’s financial position as of September 30, 2025 and as of December 31, 2024;

•the Company’s results of operations for the three and nine months ended September 30, 2025 and September 30, 2024; and

•the Company’s cash flows for the nine months ended September 30, 2025 and September 30, 2024.

Operating results for the Company for the three and nine months ended September 30, 2025 are not necessarily indicative of the results that may be expected for the full year. The unaudited interim consolidated financial statements presented herein do not contain all of the required disclosures under U.S. GAAP for annual financial statements. Notes to the financial statements which would substantially duplicate the disclosure contained in the audited financial statements for fiscal 2024 as reported in the 2024 Annual Report have been omitted. Therefore, these unaudited interim consolidated financial statements should be read in conjunction with the annual audited consolidated financial statements and related notes for Centessa Pharmaceuticals plc found in the Form 10-K for the year ended December 31, 2024 filed with the SEC.

The Company’s unaudited interim consolidated financial statements include the accounts of Centessa Pharmaceuticals plc, and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation.

Investments in Marketable Securities

The Company invests its excess cash in money market funds, U.S. Treasury securities, U.S. government agency securities, corporate debt securities and commercial paper. The Company’s investment policy limits investments to money market funds, certain types of debt securities issued by the U.S. Government and its agencies, corporate notes and commercial paper, and places restrictions on the credit ratings, maturities and concentration by type and issuer. Securities with original

maturities of three months or less when purchased are included in cash and cash equivalents. We consider investments with original maturities greater than three months and remaining maturities less than one year to be short-term investments, while remaining maturities greater than one year are classified as long-term investments.

As of September 30, 2025, investments in U.S. government Treasury and agency securities, corporate notes and commercial paper were classified as available-for-sale securities, which are recorded at fair value. Unrealized holding gains and losses on available-for-sale securities are reported net of related income taxes in accumulated other comprehensive income until realized. Purchase premiums and discounts are amortized to interest income over the terms of the related securities.

Reclassifications

Certain amounts in the prior period financial statements have been reclassified to conform to the presentation of the current period financial statements. These reclassifications had no effect on previously reported net loss or comprehensive loss.

Use of Estimates

The preparation of unaudited interim consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the unaudited interim consolidated financial statements and the reported amounts of expenses during the reporting period. Actual results could differ from those estimates.

Estimates and assumptions are periodically reviewed and the effects of revisions are reflected in the unaudited interim consolidated financial statements in the period they are determined to be necessary. On an ongoing basis, an evaluation of estimates and judgments are required, including those related to accrued and prepaid research and development expenses, share-based compensation expense and tax related matters. Estimates are based on historical experience, known trends and events, and various other factors that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Changes in estimates are recorded in the period in which they become known. Actual results may differ from these estimates under different assumptions or conditions.

License and other revenue

The Company recognizes revenues from collaboration, license or other research or sale arrangements when or as performance obligations are satisfied. For milestone payments, the Company assesses, at contract inception, whether the milestones are considered probable of being achieved. If it is probable that a significant revenue reversal will occur, the Company will not record revenue until the uncertainty has been resolved. Milestone payments that are contingent upon regulatory approval are not considered probable until the approvals are obtained as it is outside of the control of the Company. If it is probable that significant revenue reversal will not occur, the Company will estimate the milestone payments using the most likely amount method. The Company reassesses the milestones each reporting period to determine the probability of

achievement. Any potential consideration received in the form of royalty or sales-based milestones will be recorded when the customer’s subsequent sales or usages occur.

Net Loss Per Ordinary Share

The following potentially dilutive securities have been excluded from the computation of diluted weighted-average ordinary shares outstanding for the nine months ended September 30, 2025 and September 30, 2024, as they would be anti-dilutive:


	Nine Months Ended September 30, 2025	Nine Months Ended September 30, 2024
Unvested ordinary shares	—	140,454
Restricted stock units	1,035,401	1,833,984
Stock options	20,876,176	18,524,900
	21,911,577	20,499,338

New Income Tax Legislation

On July 4, 2025, the One Big Beautiful Bill Act (“OBBBA”) was enacted. Key income tax provisions of the OBBBA include the repeal of the mandatory capitalization of research and development (“R&D”) expenditures under Internal Revenue Code Section 174, thereby reinstating full expensing of R&D costs beginning in 2025, the extension of bonus depreciation, and certain revisions to international tax regimes.

The Company recognized the income tax effects of the OBBBA in its consolidated financial statements for the quarter ended September 30, 2025, in accordance with ASC 740, Income Taxes. The enactment of the OBBBA resulted in a reduction to the Company’s income tax liability for the current fiscal year, primarily reflecting the accelerated recognition of the deferred tax asset related to previously capitalized R&D expenditures. The provisions of the OBBBA did not have a material impact on the Company’s effective tax rate for the period.

Fair Value Measurement (Tables)

9 Months Ended

Sep. 30, 2025

Fair Value Disclosures [Abstract]

Schedule of Fair Value, Financial Assets Measured on Recurring Basis

The following fair value hierarchy table presents information about the Company’s financial assets measured and carried at fair value (amounts in thousands):


	Fair value measurement at reporting date using
	Quoted prices in active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)		Total
September 30, 2025
Assets
Money Market fund	$	28,397	$	—	$	—	$	28,397
U.S. Treasury and government agency securities	72,618		90,581		—		163,199
Corporate debt securities	—		110,295		—		110,295
Commercial paper	—		24,734		—		24,734
Total	$	101,015	$	225,610	$	—	$	326,625


December 31, 2024
Assets
Money Market fund	$	217,515	$	—	$	—	$	217,515
U.S. Treasury securities	171,885		—		—		171,885
Total	$	389,400	$	—	$	—	$	389,400

Schedule of Debt Securities, Fair Value of U.S. Treasury Securities and Money Market Fund

The following represents the amortized cost bases and fair values of the Company’s fixed income investments as of September 30, 2025 (amounts in thousands):


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Money Market fund, included in Cash and cash equivalents	$	28,397	$	—	$	—	$	28,397

U.S. Treasury and government agency securities, included in:

Short-term investments	$	128,447	$	44	$	(20)	$	128,471
Long-term investments	34,712		42		(26)		34,728
Total U.S. Treasury and government agency securities	$	163,159	$	86	$	(46)	$	163,199

Corporate debt securities, included in:
Short-term investments	$	42,125	$	75	$	(2)	$	42,198
Long-term investments	67,809		297		(9)		68,097
Total Corporate debt securities	$	109,934	$	372	$	(11)	$	110,295

Commercial paper, included in:

Short-term investments	$	24,726	$	8	$	—	$	24,734
Total Commercial paper	$	24,726	$	8	$	—	$	24,734

In aggregate:
Investments above with no unrealized loss	$	245,157	$	466	$	—	$	245,623
Investments above with unrealized loss	81,059		—		(57)		81,002
Total investments	$	326,216	$	466	$	(57)	$	326,625

- Definition

Tabular disclosure of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
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-Subparagraph (aa)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-2

Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (aaa)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-2

Reference 8: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-2

Reference 9: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-3

Reference 10: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-3

Reference 11: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-3

Reference 12: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-3

+ Details

Commitments and Contingencies - Future Lease Payments and Sublease Income under Non-Cancelable Operating Leases (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Operating Leases
2025	$ 408
2026	1,667
2027	1,700
2028	1,734
2029	1,769
Thereafter	5,521
Total	12,799
Less: Imputed interest	(4,356)
Total operating lease liabilities	8,443
Less: current portion	(684)	$ (602)
Lease liabilities, net of current portion	7,759	$ 8,286
Sublease Income
2025	89
2026	362
2027	370
2028	345
2029	0
Thereafter	0
Total	$ 1,166

Share-based Compensation - Narrative (Details) $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2025 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant date fair value of options granted (in dollars per share) \| $ / shares	$ 11.40
Unrecognized compensation expense related to unvested stock option awards \| $	$ 67.1
Shares repurchased (in shares)	0
Stock issued during period (in shares)	0
Remaining shares reserved for issuance (in shares)	2,708,515
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected weighted average recognition period	3 years 1 month 6 days
2021 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for grant (in shares)	11,454,749

Consolidated Statements of Shareholders' Equity (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Unrealized gain on available for sale securities, tax	$ 0.1	$ 0.3	$ 0.1	$ 0.7
Reclassifications to net loss, net of tax
Reclassification adjustment for realized net gain on available for sale marketable securities included in net loss, tax benefit			$ (0.8)	$ (0.4)

Fair Value Measurement - Schedule of Fair Value, Financial Assets and Liabilities Measured on Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Assets
Debt securities, available-for-sale, fair value	$ 326,625
U.S. Treasury and government agency securities
Assets
Debt securities, available-for-sale, fair value	163,199
Corporate debt securities
Assets
Debt securities, available-for-sale, fair value	110,295
Commercial paper
Assets
Debt securities, available-for-sale, fair value	24,734
Fair Value, Recurring
Assets
Total	326,625	$ 389,400
Fair Value, Recurring \| U.S. Treasury and government agency securities
Assets
Debt securities, available-for-sale, fair value	163,199
Fair Value, Recurring \| Corporate debt securities
Assets
Debt securities, available-for-sale, fair value	110,295
Fair Value, Recurring \| Commercial paper
Assets
Debt securities, available-for-sale, fair value	24,734
Fair Value, Recurring \| U.S. Treasury securities
Assets
Debt securities, available-for-sale, fair value		171,885
Fair Value, Recurring \| Money Market fund
Assets
Money market fund, included in cash and cash equivalents, fair value	28,397	217,515
Quoted prices in active markets for identical assets (Level 1) \| Fair Value, Recurring
Assets
Total	101,015	389,400
Quoted prices in active markets for identical assets (Level 1) \| Fair Value, Recurring \| U.S. Treasury and government agency securities
Assets
Debt securities, available-for-sale, fair value	72,618
Quoted prices in active markets for identical assets (Level 1) \| Fair Value, Recurring \| Corporate debt securities
Assets
Debt securities, available-for-sale, fair value	0
Quoted prices in active markets for identical assets (Level 1) \| Fair Value, Recurring \| Commercial paper
Assets
Debt securities, available-for-sale, fair value	0
Quoted prices in active markets for identical assets (Level 1) \| Fair Value, Recurring \| U.S. Treasury securities
Assets
Debt securities, available-for-sale, fair value		171,885
Quoted prices in active markets for identical assets (Level 1) \| Fair Value, Recurring \| Money Market fund
Assets
Money market fund, included in cash and cash equivalents, fair value	28,397	217,515
Significant other observable inputs (Level 2) \| Fair Value, Recurring
Assets
Total	225,610	0
Significant other observable inputs (Level 2) \| Fair Value, Recurring \| U.S. Treasury and government agency securities
Assets
Debt securities, available-for-sale, fair value	90,581
Significant other observable inputs (Level 2) \| Fair Value, Recurring \| Corporate debt securities
Assets
Debt securities, available-for-sale, fair value	110,295
Significant other observable inputs (Level 2) \| Fair Value, Recurring \| Commercial paper
Assets
Debt securities, available-for-sale, fair value	24,734
Significant other observable inputs (Level 2) \| Fair Value, Recurring \| U.S. Treasury securities
Assets
Debt securities, available-for-sale, fair value		0
Significant other observable inputs (Level 2) \| Fair Value, Recurring \| Money Market fund
Assets
Money market fund, included in cash and cash equivalents, fair value	0	0
Significant unobservable inputs (Level 3) \| Fair Value, Recurring
Assets
Total	0	0
Significant unobservable inputs (Level 3) \| Fair Value, Recurring \| U.S. Treasury and government agency securities
Assets
Debt securities, available-for-sale, fair value	0
Significant unobservable inputs (Level 3) \| Fair Value, Recurring \| Corporate debt securities
Assets
Debt securities, available-for-sale, fair value	0
Significant unobservable inputs (Level 3) \| Fair Value, Recurring \| Commercial paper
Assets
Debt securities, available-for-sale, fair value	0
Significant unobservable inputs (Level 3) \| Fair Value, Recurring \| U.S. Treasury securities
Assets
Debt securities, available-for-sale, fair value		0
Significant unobservable inputs (Level 3) \| Fair Value, Recurring \| Money Market fund
Assets
Money market fund, included in cash and cash equivalents, fair value	$ 0	$ 0

Summary of Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2025

Accounting Policies [Abstract]

Schedule of Antidilutive Securities Excluded from Computation of Diluted Weighted-Average Ordinary Shares Outstanding


	Nine Months Ended September 30, 2025	Nine Months Ended September 30, 2024
Unvested ordinary shares	—	140,454
Restricted stock units	1,035,401	1,833,984
Stock options	20,876,176	18,524,900
	21,911,577	20,499,338

Debt - Schedule of Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Debt Instrument [Line Items]
End of term charge	$ 5,500	$ 5,500
Unamortized debt issuance costs and unamortized end of term charge	(5,684)	(6,560)
Loan and Security Agreement (carried at amortized cost)	109,816	108,940
Significant other observable inputs (Level 2) \| Fair Value, Recurring
Debt Instrument [Line Items]
The fair value of LSA, classified as Level 2 under ASC Topic 820, Fair Value Measurement	109,038	109,450
Secured Debt \| Line of Credit
Debt Instrument [Line Items]
Principal amount	$ 110,000	$ 110,000

Balance Sheet Components - Components of Property, Plant, and Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	$ 1,906	$ 1,535
Less: Accumulated depreciation	(1,012)	(791)
Property and equipment, net	894	744
Computer equipment
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	1,139	768
Office furniture
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	724	724
Other
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	$ 43	$ 43

Balance Sheet Components - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Research and development expenses	$ 5,230	$ 6,314
Interest receivable	1,932	287
Value added tax receivable	1,160	1,528
Insurance related expenses	1,259	840
Other	2,759	1,495
Prepaid expenses and other current assets	$ 12,340	$ 10,464

Program Termination Costs - Narrative (Details) $ in Millions	3 Months Ended
	Dec. 31, 2024 USD ($)
Restructuring Cost and Reserve [Line Items]
Accrued contract termination costs	$ 31.5
Contract Termination
Restructuring Cost and Reserve [Line Items]
Accrued contract termination costs	30.3
Severance-Related
Restructuring Cost and Reserve [Line Items]
Accrued contract termination costs	$ 1.2

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References + Details