0001628280-26-031696 | 10-Q | XBRL Viewer

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Organization and Description of Business	3 Months Ended
Organization and Description of Business	Mar. 31, 2026
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Description of Business	1. Organization and Description of Business Zura Bio Limited, a Cayman Islands exempted company, together with its subsidiaries (collectively, the “Company” or “Zura”), is a clinical-stage biotechnology company developing novel and differentiated medicines for patients with autoimmune and inflammatory diseases, including serious and debilitating conditions with significant unmet medical need. These diseases are often chronic and biologically complex, and many patients do not achieve durable disease control with currently available therapies. The Company’s strategic focus is to identify immune-mediated diseases in which translational and clinical evidence supports the role of specific biological pathways in disease pathogenesis. The Company is currently developing its lead product candidate in ongoing Phase 2 trials while evaluating development opportunities for its clinical-stage assets, focusing on indications with unmet needs and commercial potential. Emerging Growth Company Status The Company is an emerging growth company, as defined in the Jumpstart Our Business Startups Act of 2012 (the “JOBS Act”). Under the JOBS Act, emerging growth companies can delay adopting new or revised accounting standards issued subsequent to the enactment of the JOBS Act until such time as those standards apply to private companies. The Company has elected to use the extended transition period for complying with new or revised accounting standards, and as a result of this election, the Company’s unaudited condensed consolidated financial statements (the “condensed consolidated financial statements”) may not be comparable to companies that comply with public company Financial Accounting Standards Board (“FASB”) standards’ effective dates. The Company may take advantage of these exemptions up until the last day of the fiscal year following the fifth anniversary of an offering or such earlier time that it is no longer an emerging growth company. The Company expects to no longer be an emerging growth company effective December 31, 2026. Liquidity The Company has incurred operating losses since inception and expects to continue to incur significant operating losses for the foreseeable future and may never become profitable. The Company has an accumulated deficit of $248.8 million and $224.5 million as of March 31, 2026 and December 31, 2025, respectively, and a net loss of $24.2 million and $17.4 million for the three months ended March 31, 2026 and 2025, respectively. The Company’s existing sources of liquidity as of March 31, 2026 include $225.6 million in cash and cash equivalents. The Company has relied primarily on public and private equity financings to fund operations. The Company’s cash requirements include, but are not limited to, clinical development, product candidate manufacturing costs, and working capital requirements. The Company expects that such operating losses and negative cash flows from operations will continue for the foreseeable future but has sufficient liquidity to fund its operations over the next twelve months.

Condensed Consolidated Statements of Cash Flows (Unaudited) (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Subsidiary, Sale of Stock [Line Items]
Issuance of shares, transaction costs	$ 8.0
At The Market Offering
Subsidiary, Sale of Stock [Line Items]
Issuance of shares, transaction costs	0.2	$ 0.2
Pre-Funded Warrants
Subsidiary, Sale of Stock [Line Items]
Issuance of shares, transaction costs	$ 0.7

Shareholders' Equity

3 Months Ended

Mar. 31, 2026

Shareholders' Equity [Abstract]

Shareholders' Equity

6. Shareholders’ Equity

The Company has authorized 300,000,000 Class A Ordinary Shares, par value of $0.0001 and 1,000,000 preferred shares, par value of $0.0001.

Shelf Registration and ATM Program

The Company filed a shelf registration statement on Form S-3 (the “Shelf Registration Statement”), which was declared effective on September 17, 2024. Pursuant to the Shelf Registration Statement, the Company may offer and sell ordinary shares, preference shares, debt securities, warrants and or units having an aggregate public offering price of up to $300.0 million. In connection with the filing of the Shelf Registration Statement, the Company also entered into a sales agreement (the “Sales Agreement”) with Leerink Partners LLC (“Leerink Partners”), relating to the sale of the Company’s Class A Ordinary Shares having an aggregate gross sales price of up to $125.0 million, from time to time through Leerink Partners, acting as sales agent (the “ATM”).

During the three months ended March 31, 2026, no Class A Ordinary Shares were sold under the ATM.

As of March 31, 2026, $114.0 million of Class A Ordinary Shares remained available for sale under the Sales Agreement.

February 2026 Equity Offering

In February 2026, the Company entered into an underwriting agreement with Leerink Partners LLC, Piper Sandler & Co. and Cantor Fitzgerald & Co., as representatives of the several underwriters listed therein, pursuant to which the Company issued and sold 21,200,000 Class A Ordinary Shares, par value $0.0001 per share, at a price to the public of $6.25 per share, which included 3,000,000 additional Class A Ordinary Shares sold upon exercise in full by the underwriters of their option to purchase additional shares of stock in the offering, along with pre-funded warrants to purchase 1,800,000 Ordinary Shares at a price to the public of $6.249 per Pre-Funded Warrant, which represents the per share public offering price for the Shares less the $0.001 exercise price of each Pre-Funded Warrant (the “February 2026 Equity Offering”). The net proceeds from the February 2026 Equity Offering were approximately $134.6 million after deducting underwriting discounts and commissions and offering expenses.

Pre-Funded Warrants

In connection with the February 2026 Equity Offering, the Company sold to accredited investors pre-funded warrants to purchase up to 1,800,000 Class A Ordinary Shares at a price of $6.249 per pre-funded warrant for an aggregate purchase price of approximately $11.2 million.

As of March 31, 2026 and December 31, 2025, there was an aggregate 29,295,396 and 27,495,396 pre-funded warrants outstanding, respectively, each with an exercise price of $0.001.

During each of the three months ended March 31, 2026 and 2025, no Class A Ordinary Shares were issued in connection with the exercise of Pre-Funded Warrants.

Each Pre-Funded Warrant is exercisable for one Class A Ordinary Share at any time or times until the Pre-Funded Warrants are exercised in full. A holder of the Pre-Funded Warrants (together with its affiliates and other attribution parties) may not exercise any portion of a Pre-Funded Warrant to the extent that immediately prior to or after giving effect to such exercise the holder would beneficially own more than 4.99% or 9.99%, depending on the holder of the Company’s outstanding Class A Ordinary Shares immediately after exercise, which percentage may be increased or decreased to any other percentage specified not in excess of 19.99% at the holder’s election upon 61 days’ notice to the Company subject to the terms of the Pre-Funded Warrants.

Ordinary Shares Reserved for Issuance

A summary of shares reserved for issuance as of March 31, 2026 is summarized below:


			March 31, 2026
Shares issuable upon exercise of pre-funded warrants to purchase Class A Ordinary Shares			29,295,396
Shares issuable upon exercise of options to purchase Class A Ordinary Shares			17,892,060
Shares available for grant under 2023 Equity Incentive Plan and ESPP			3,845,063
Shares issuable upon release of restricted share units			583,282
Total shares reserved for issuance			51,615,801

Organization and Description of Business (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025	Dec. 31, 2025
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accumulated deficit	$ 248,770		$ 224,547
Net loss	24,223	$ 17,442
Cash and cash equivalents	$ 225,594		$ 109,407

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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+ Details

- Definition

Amount of accumulated undistributed earnings (deficit).

+ References + Details

Accounts Payable and Accrued Expenses (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Accounts Payable and Accrued Liabilities, Current [Abstract]
Accrued research and development costs	$ 5,490	$ 6,575
Accrued bonus	1,131	3,319
Accounts payable	2,083	1,279
Accrued professional fees	1,407	559
Other accrued expenses	1,634	678
Total accounts payable and accrued expenses	$ 11,745	$ 12,410

Shareholders' Equity - Schedule of shares reserved for issuance (Details)	Mar. 31, 2026 shares
Shareholders' Equity
Total shares reserved for issuance	51,615,801
Shares available for grant under 2023 Equity Incentive Plan and ESPP
Shareholders' Equity
Total shares reserved for issuance	3,845,063
Shares issuable upon exercise of options to purchase Class A Ordinary Shares
Shareholders' Equity
Total shares reserved for issuance	17,892,060
Restricted Stock Units (RSUs)
Shareholders' Equity
Total shares reserved for issuance	583,282
Shares issuable upon exercise of pre-funded warrants to purchase Class A Ordinary Shares
Shareholders' Equity
Total shares reserved for issuance	29,295,396

Share-based Compensation - Schedule of Restricted Share Awards (Details) - Restricted share awards	3 Months Ended
	Mar. 31, 2026 $ / shares shares
Number of RSUs
Beginning balance (in shares) \| shares	249,997
Vested (in shares) \| shares	(124,998)
Ending balance (in shares) \| shares	124,999
Weighted Average Grant Date Fair Value
Beginning balance, Weighted Average Grant Date Fair Value (in dollars per share) \| $ / shares	$ 8.16
Vested, Weighted Average Grant Date Fair Value (in dollars per share) \| $ / shares	8.16
Ending balance, Weighted Average Grant Date Fair Value (in dollars per share) \| $ / shares	$ 8.16

Share-based Compensation - Schedule of Weighted-Average Assumptions Used to Estimate The Fair Value (Details) - $ / shares	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Share-based Compensation
Share price	6.32
Expected volatility	105.00%
Risk-free rate	4.20%
Expected term (in years)	4 years 10 months 24 days
Expected dividend yield	0.00%
Equity Incentive Plan 2023
Share-based Compensation
Share price	6.32	1.20
Expected volatility	103.80%	99.70%
Risk-free rate	4.00%	4.10%
Expected term (in years)	5 years 3 months 18 days	6 years 1 month 6 days
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.

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+ Details

Share-based Compensation - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands			3 Months Ended		12 Months Ended
	Jan. 21, 2026	Mar. 16, 2023	Mar. 31, 2026	Mar. 31, 2025	Dec. 31, 2025
Share-based Compensation
Share based payment award, option to vest (in years)		4 years
Expiration term (in years)		10 years
Total share-based compensation expense			$ 5,008	$ 3,644
Share-Based Payment Arrangement, Option
Share-based Compensation
Unrecognized share-based compensation expense			$ 25,000
Share-based compensation expense expected to be recognized over a weighted average period			2 years 10 months 24 days
Market-Based Share Options
Share-based Compensation
Expiration term (in years)	10 years
Number of options granted (in shares)	505,881
Consecutive trading days	30 days
Granted (in dollars per share)	$ 6.32
Total share-based compensation expense			$ 700	200
Restricted Stock Units (RSUs)
Share-based Compensation
Unrecognized share-based compensation expense			$ 2,000
Share-based compensation expense expected to be recognized over a weighted average period			1 year 2 months 12 days
Total share-based compensation expense			$ 400
Restricted share awards
Share-based Compensation
Unrecognized share-based compensation expense			$ 1,000
Share-based compensation expense expected to be recognized over a weighted average period			1 year
Total share-based compensation expense			$ 300	$ 300
Maximum
Share-based Compensation
Share-based compensation arrangement by share-based payment award, number of shares authorized			20,573,023
Employee Stock Purchase Plan
Share-based Compensation
Percentage of discount for eligible employees		15.00%
Number of options granted (in shares)			0
Outside of equity plan \| Directors Executives And Employees
Share-based Compensation
Number of options granted (in shares)			2,055,314		2,055,314
Equity Incentive Plan 2023
Share-based Compensation
Number of options granted (in shares)			3,571,435
Weighted average grant date fair value			$ 5.08	$ 0.97
Granted (in dollars per share)			$ 6.32
Equity Award Mofication \| Share-Based Payment Arrangement, Option
Share-based Compensation
Accelerated vesting percent of shares	25.00%
Total share-based compensation expense			$ 1,500

Summary of Significant Accounting Policies

3 Months Ended

Mar. 31, 2026

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

2. Summary of Significant Accounting Policies

Basis of Presentation and Principles of Consolidation

The Company’s condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and include the accounts of its consolidated subsidiaries. In comparative periods, where applicable, other shareholders’ interests in the Company’s subsidiaries, Z33 Bio, Inc. (“Z33”) and ZB17 LLC (“ZB17”), are shown in the condensed consolidated financial statements as redeemable noncontrolling interest and noncontrolling interest, respectively. All intercompany balances and transactions have been eliminated in consolidation.

These condensed consolidated financial statements are presented in accordance with the rules and regulations of the Securities and Exchange Commission (the “SEC”) and do not include all disclosures normally required in annual consolidated financial statements prepared in accordance with U.S. GAAP. As such, the information included herein should be read in conjunction with the Company’s consolidated financial statements and accompanying notes as of and for the year ended December 31, 2025 (the “audited consolidated financial statements”) that were included in the Company’s Form 10-K filed with the SEC on March 19, 2026 (the “Annual Report”). In management’s opinion, these condensed

consolidated financial statements have been prepared on the same basis as the audited consolidated financial statements and reflect all adjustments, which include normal recurring adjustments, necessary for the fair statement of the Company’s financial position as of March 31, 2026 and the results of operations for the three months ended March 31, 2026 and 2025. The results of operations for the three months ended March 31, 2026 are not necessarily indicative of the results to be expected for the full year ending December 31, 2026 or any other future interim or annual period.

Significant Accounting Policies

There have been no material changes in the Company’s significant accounting policies from those that were disclosed in Note 2, Summary of Significant Accounting Policies, included in the audited consolidated financial statements in the Company’s Annual Report.

Use of Estimates

The preparation of condensed consolidated financial statements in conformity with U.S. GAAP requires the Company’s management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements, as well as the reported amounts of expenses during the reporting period. Actual results could differ from those estimates. Significant estimates and assumptions reflected in the condensed consolidated financial statements relate to and include, but are not limited to, accrued research and development expenses, the fair value of share-based compensation, the fair value of redeemable noncontrolling interest, and the valuation allowance of deferred tax assets resulting from net operating losses.

Risks and Uncertainties

The Company is subject to risks common to early-stage companies in the biotechnology industry, including, but not limited to, development by the Company or its competitors of technological innovations, risks of failure of clinical studies, dependence on key personnel, protection of proprietary technology, compliance with government regulations, and ability to transition from clinical manufacturing to commercial production of products.

The Company’s product candidates will require approvals from the United States Food and Drug Administration (“FDA”) and comparable foreign regulatory agencies prior to commercial sales in their respective jurisdictions. There can be no assurance that any product candidate will receive the necessary approvals. If the Company was denied approval, approval was delayed or the Company was unable to maintain approval for any product candidate, it could have a material adverse impact on the Company.

The Company has significant cash balances at financial institutions which throughout the year regularly exceed the federally insured limit of $250,000. Any loss incurred or a lack of access to such funds could have a significant adverse impact on the Company’s financial condition, results of operations, and cash flows.

Segments

Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision-maker (“CODM”) in making decisions regarding resource allocation and assessing performance. The Company’s CODM is the Chief Executive Officer. The Company and the CODM view its operations and manage its business in one operating segment, developing novel medicines for immune and inflammatory disorders. The Company has business activities in different regions that are managed on a consolidated basis.

The accounting policies of the Company’s segment are the same as those described within this footnote. The CODM uses net loss, that is reported in the condensed consolidated statements of operations, to assess performance for the Company’s segment and decide how to allocate resources. The measure of segment assets is reported on the condensed consolidated balance sheet as total consolidated assets. The following tables represent information provided to the CODM:


	For the Three Months Ended March 31,
	2026		2025
Research and development expenses:
Wages and benefits	$	2,603	$	1,466
Tibulizumab SSc program	3,200		2,763
Tibulizumab HS program	4,701		1,274
Tibulizumab general	2,929		3,706
Additional product candidates (torudokimab and crebankitug)	171		291
Unallocated research and development expenses	573		456
General and administrative expenses:
Wages and benefits	2,686		2,591
Other general and administrative expenses	3,612		3,054
Stock-based compensation	5,008		3,644
Other segment items*	(1,260)		(1,803)
Net loss	$	24,223	$	17,442

*Other segment items include Depreciation and amortization, Interest income, and Other income (net).

R&D Incentive Credits

The Company is eligible to obtain certain R&D incentive credits (the “R&D Credits”), through participation in the United Kingdom’s (“U.K.”) R&D Small and Medium Enterprise and the Research and Development Expenditure Credit tax relief programs.

The R&D Credits are calculated as a percentage of qualifying R&D expenses incurred as part of research projects. The R&D Credits are used as tax credits for the Company with the resulting amount being payable in cash by the U.K. government (tax authority) to the Company. The R&D Credits are subject to future audits by the U.K. tax authority within defined periods.

Although the incentive credits are administered through the local tax authority, the Company has accounted for the incentives outside of the scope of FASB Accounting Standards Codification Topic 740, Income Taxes, since the incentives are not linked to the Company’s taxable income and can be realized regardless of whether the Company has generated taxable income in the respective jurisdictions. The Company accounts for these incentive credits as a government grant which analogizes with International Accounting Standards 20 (“IAS 20”), Accounting for Government Grants and Disclosure of Government Assistance.

In accordance with IAS 20, the Company will recognize the R&D Credits when it has reasonable assurance that the R&D Credits will be received. As the Company has only filed two claims under the tax relief programs as of March 31, 2026, it has determined that reasonable assurance will be met upon cash receipt. In April 2025, the Company filed a claim for an R&D Credit for $1.0 million that was not received as of March 31, 2026.

Net Loss Per Share

Basic net loss per share is computed by dividing net loss by the weighted-average number of the Company's Class A ordinary shares (“Class A Ordinary Shares”) and pre-funded warrants outstanding during the period. The pre-funded warrants are included in the computation of basic and diluted net loss per ordinary share as the exercise price is negligible and the pre-funded warrants are fully vested and exercisable. Basic and diluted net loss per share were the same for each

period presented as the inclusion of all potentially dilutive securities outstanding would have been anti-dilutive due to the Company’s net loss.

The table below provides potentially dilutive securities not included in the calculation of the diluted net loss per share as of the periods presented because to do so would be anti-dilutive:


	March 31,
	2026	2025
Shares issuable upon exercise of options to purchase Class A Ordinary Shares	15,525,157	13,593,638
Shares issuable upon exercise of Z33 Series Seed Preferred Shares Put Right	—	2,000,000
Shares issuable upon vesting of restricted share units	573,282	859,923
Restricted share awards	124,999	249,997
Total	16,223,438	16,703,558

Recently Issued Accounting Pronouncements

From time to time, new accounting pronouncements are issued by the FASB or other standard setting bodies and adopted by the Company as of the specified effective date. Unless otherwise discussed, the impact of recently issued standards that are not yet effective will not have a material impact on the Company’s financial position, results of operations, or cash flows upon adoption.

In November 2024, the FASB issued Accounting Standards Update (“ASU”) 2024-03, Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses. This ASU requires disclosure in the notes to financial statements of the nature of certain expenses included in the income statement. ASU 2024-03 will be effective for annual reporting periods beginning after December 15, 2026, and interim reporting periods beginning after December 15, 2027. Early adoption is permitted. The Company is currently evaluating the impact of ASU 2024-03 and expects to adopt it for the year ending December 31, 2027.

In December 2025, the FASB issued ASU 2025-10, Government Grants (Topic 832): Accounting for Government Grants Received by Business Entities, which establishes guidance on the recognition, measurement, and presentation of government grants received by business entities. The amendments in ASU 2025-10 are effective for annual reporting periods beginning after December 15, 2028, and interim reporting periods within those annual reporting periods, with early adoption permitted. The guidance can be applied under a modified prospective approach, a modified retrospective approach, or a full retrospective approach. The Company is currently assessing the impact of the adoption of this guidance on its consolidated financial statements and disclosures.

License Agreements - 2022 Lilly License (Details) - License agreement with Lilly - USD ($)	Mar. 31, 2026	Dec. 08, 2022
License Agreements
Maximum amount of development and regulatory milestone payments		$ 155,000,000.0
Maximum amount of sales milestone payments		$ 440,000,000.0
Contingent payments due	$ 0

Share-based Compensation - Schedule of Share-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Share-based Compensation
Total share-based compensation expense	$ 5,008	$ 3,644
Research and development
Share-based Compensation
Total share-based compensation expense	569	518
General and administrative
Share-based Compensation
Total share-based compensation expense	$ 4,439	$ 3,126

- 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

Fair Value Measurements (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Fair Value Measurements
Cash equivalents	$ 220,248	$ 106,310
Level 1
Fair Value Measurements
Cash equivalents	220,248	106,310
Level 2
Fair Value Measurements
Cash equivalents	0	0
Level 3
Fair Value Measurements
Cash equivalents	$ 0	$ 0

Share-based Compensation (Tables)

3 Months Ended

Mar. 31, 2026

Share-based Compensation

Schedule of Weighted-Average Assumptions Used to Estimate The Fair Value

The following weighted-average assumptions were used at the grant date to determine the fair value of Company’s Market-Based Share Options granted during the three months ended March 31, 2026:


	For the Three Months Ended March 31,
	2026
Share price	$	6.32
Expected volatility	105.0		%
Risk-free rate	4.2		%
Expected term (in years)	4.9
Expected dividend yield	—		%

Schedule of Restricted Share Units

The following table summarizes the Company’s RSU activity for the three months ended March 31, 2026:


	Number of RSUs	Weighted Average Grant Date Fair Value
Unvested RSUs outstanding as of December 31, 2025	583,282	$	5.99
Unvested RSUs outstanding as of March 31, 2026	583,282	$	5.99

Schedule of Restricted Share Awards

The following table summarizes the Company’s RSA activity for the three months ended March 31, 2026:


	Number of RSAs	Weighted Average Grant Date Fair Value
Unvested RSAs outstanding as of December 31, 2025	249,997	$	8.16
Vested	(124,998)	8.16
Unvested RSAs outstanding as of March 31, 2026	124,999	$	8.16

Schedule of Share-Based Compensation Expense

Share-based compensation expense for all equity arrangements for the three months ended March 31, 2026 and 2025 was as follows:


	For the Three Months Ended March 31,
	2026		2025
Research and development	$	569	$	518
General and administrative	4,439		3,126
Total share-based compensation expense	$	5,008	$	3,644

Equity Incentive Plan 2023

Share-based Compensation

Schedule of Weighted-Average Assumptions Used to Estimate The Fair Value

The following weighted-average assumptions were used to estimate the fair value of the Equity Incentive Plan share options issued during the three months ended March 31, 2026 and 2025:


	For the Three Months Ended March 31,
	2026			2025
Share price	$	6.32		$	1.20
Expected volatility	103.8		%	99.7		%
Risk-free rate	4.0		%	4.1		%
Expected term (in years)	5.3			6.1
Expected dividend yield	0		%	0		%

Schedule of Company's Share Option Activity

The following table summarizes the Company’s share option activity for the three months ended March 31, 2026:


	Number of Options	Weighted Average Exercise Price (per share)		Weighted Average Remaining Contractual Life (Years)	Aggregate Intrinsic Value (in thousands)
Options outstanding as of December 31, 2025	16,463,011	$	2.40	8.2	$	48,866
Granted	3,571,435	$	6.32
Forfeited	(2,142,386)	$	2.58
Options outstanding as of March 31, 2026	17,892,060	$	3.16	7.7	$	52,323
Options vested and exercisable as of March 31, 2026	9,002,039	$	2.26	6.4	$	33,422

- 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

Share-based Compensation - Schedule of Restricted Share Units (Details) - Restricted Stock Units (RSUs)	Mar. 31, 2026 $ / shares shares
Number of RSUs
Beginning balance (in shares) \| shares	583,282
Ending balance (in shares) \| shares	583,282
Weighted Average Grant Date Fair Value
Beginning balance, Weighted Average Grant Date Fair Value (in dollars per share) \| $ / shares	$ 5.99
Ending balance, Weighted Average Grant Date Fair Value (in dollars per share) \| $ / shares	$ 5.99

Defined Contribution Plans	3 Months Ended
Defined Contribution Plans	Mar. 31, 2026
Defined Contribution Plan [Abstract]
Defined Contribution Plans	9. Defined Contribution Plans The Company maintains a 401(k) defined contribution retirement plan (the “401(k) Plan”) for all of its U.S. employees. For the 401(k) Plan, the Company makes a matching contribution up to a maximum of 6% of an employee’s annual salary. For U.K. employees, the Company contributes up to 6% of an employee’s annual salary to defined contribution retirement pension plans (the “U.K. Defined Contribution Plan” and, together with the 401(k) Plan, the “Defined Contribution Plans”). Contributions made by the Company vest 100% upon contribution. For the three months ended March 31, 2026 and 2025, the Company recorded expense of $0.2 million and $0.1 million, respectively, for the Defined Contribution Plans.

Commitments and Contingencies	3 Months Ended
Commitments and Contingencies	Mar. 31, 2026
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	8. Commitments and Contingencies Litigation The Company is not a party to any material legal proceedings and is not aware of any pending or threatened claims. From time to time, the Company may be subject to various legal proceedings and claims that arise in the ordinary course of its business activities.

Document and Entity Information - shares	3 Months Ended
Document and Entity Information - shares	Mar. 31, 2026	May 04, 2026
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2026
Document Transition Report	false
Entity File Number	001-40598
Entity Registrant Name	ZURA BIO LIMITED
Entity Incorporation, State or Country Code	E9
Entity Tax Identification Number	98-1725736
Entity Address, Address Line One	1489 W. Warm Springs Rd. #110
Entity Address, City or Town	Henderson
Entity Address, State or Province	NV
Entity Address, Postal Zip Code	89014
City Area Code	702
Local Phone Number	825-9872
Title of 12(b) Security	Class A Ordinary Shares
Trading Symbol	ZURA
Security Exchange Name	NASDAQ
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		94,997,710
Entity Central Index Key	0001855644
Document Fiscal Year Focus	2026
Document Fiscal Period Focus	Q1
Amendment Flag	false
Current Fiscal Year End Date	--12-31

Summary of Significant Accounting Policies (Policies)

3 Months Ended

Mar. 31, 2026

Accounting Policies [Abstract]

Basis of Presentation and Principles of Consolidation

Significant Accounting Policies

Use of Estimates

Risks and Uncertainties

Segments

R&D Incentive Credits

Net Loss Per Share

period presented as the inclusion of all potentially dilutive securities outstanding would have been anti-dilutive due to the Company’s net loss.

The table below provides potentially dilutive securities not included in the calculation of the diluted net loss per share as of the periods presented because to do so would be anti-dilutive:


	March 31,
	2026	2025
Shares issuable upon exercise of options to purchase Class A Ordinary Shares	15,525,157	13,593,638
Shares issuable upon exercise of Z33 Series Seed Preferred Shares Put Right	—	2,000,000
Shares issuable upon vesting of restricted share units	573,282	859,923
Restricted share awards	124,999	249,997
Total	16,223,438	16,703,558

Recently Issued Accounting Pronouncements

- Definition

Disclosure of accounting policy for segment reporting.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 41
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+ Details

- Definition

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

+ References

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+ Details

Shareholders' Equity (Tables)

3 Months Ended

Mar. 31, 2026

Shareholders' Equity [Abstract]

Schedule of shares reserved for issuance

A summary of shares reserved for issuance as of March 31, 2026 is summarized below:


			March 31, 2026
Shares issuable upon exercise of pre-funded warrants to purchase Class A Ordinary Shares			29,295,396
Shares issuable upon exercise of options to purchase Class A Ordinary Shares			17,892,060
Shares available for grant under 2023 Equity Incentive Plan and ESPP			3,845,063
Shares issuable upon release of restricted share units			583,282
Total shares reserved for issuance			51,615,801

Defined Contribution Plans (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Defined Contribution Plans
Employers matching contribution, annual vesting percentage	100.00%
Defined contribution plan expenses	$ 0.2	$ 0.1
Maximum \| US
Defined Contribution Plans
Matching contribution percent	6.00%
Maximum \| UK
Defined Contribution Plans
Matching contribution percent	6.00%

Summary of Significant Accounting Policies (Tables)

3 Months Ended

Mar. 31, 2026

Accounting Policies [Abstract]

Schedule of Segment Reporting Information, by Segment

The following tables represent information provided to the CODM:


	For the Three Months Ended March 31,
	2026		2025
Research and development expenses:
Wages and benefits	$	2,603	$	1,466
Tibulizumab SSc program	3,200		2,763
Tibulizumab HS program	4,701		1,274
Tibulizumab general	2,929		3,706
Additional product candidates (torudokimab and crebankitug)	171		291
Unallocated research and development expenses	573		456
General and administrative expenses:
Wages and benefits	2,686		2,591
Other general and administrative expenses	3,612		3,054
Stock-based compensation	5,008		3,644
Other segment items*	(1,260)		(1,803)
Net loss	$	24,223	$	17,442

Schedule of potentially dilutive securities not included in calculation of diluted net loss per share because to do so would be anti-dilutive

The table below provides potentially dilutive securities not included in the calculation of the diluted net loss per share as of the periods presented because to do so would be anti-dilutive:


	March 31,
	2026	2025
Shares issuable upon exercise of options to purchase Class A Ordinary Shares	15,525,157	13,593,638
Shares issuable upon exercise of Z33 Series Seed Preferred Shares Put Right	—	2,000,000
Shares issuable upon vesting of restricted share units	573,282	859,923
Restricted share awards	124,999	249,997
Total	16,223,438	16,703,558

License Agreements - 2023 Lilly License (Details) - License agreement with Lilly	Apr. 26, 2023 USD ($) payment	Mar. 31, 2026 USD ($)	Dec. 08, 2022 USD ($)
License Agreements
Maximum amount of development and regulatory milestone payments			$ 155,000,000.0
Maximum amount of sales milestone payments			$ 440,000,000.0
Contingent payments due		$ 0
Stone Peach Properties, LLC
License Agreements
Contingent payments due		$ 0
BAFFX17, Ltd
License Agreements
Number of development and regulatory milestone payments \| payment	4
Maximum amount of development and regulatory milestone payments	$ 155,000,000.0
Maximum amount of sales milestone payments	$ 440,000,000.0
Period for payment of milestone payment	12 years

Accounts Payable and Accrued Expenses

3 Months Ended

Mar. 31, 2026

Accounts Payable and Accrued Liabilities, Current [Abstract]

Accounts Payable and Accrued Expenses

4. Accounts Payable and Accrued Expenses

Accounts payable and accrued expenses is comprised of the following as of March 31, 2026 and December 31, 2025:


	March 31, 2026		December 31, 2025
Accrued research and development costs	$	5,490	$	6,575
Accrued bonus	1,131		3,319
Accounts payable	2,083		1,279
Accrued professional fees	1,407		559
Other accrued expenses	1,634		678
Total accounts payable and accrued expenses	$	11,745	$	12,410

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Current assets
Cash and cash equivalents	$ 225,594	$ 109,407
Prepaid expenses and other current assets	1,410	2,903
Total current assets	227,004	112,310
Property and equipment, net	125	126
Other assets	1,512	1,512
Total assets	228,641	113,948
Current liabilities
Accounts payable and accrued expenses	11,745	12,410
Total current liabilities	11,745	12,410
Total liabilities	11,745	12,410
Commitments and contingencies (Note 8)
Shareholders’ Equity
Class A Ordinary Shares, $0.0001 par value; 300,000,000 shares authorized as of March 31, 2026 and December 31, 2025; 94,880,710 and 73,680,710 shares issued and outstanding as of March 31, 2026 and December 31, 2025, respectively	9	7
Additional paid-in capital	465,657	326,078
Accumulated deficit	(248,770)	(224,547)
Total shareholders’ equity	216,896	101,538
Total liabilities and shareholders’ equity	$ 228,641	$ 113,948

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Operating expenses:
Research and development	$ 14,746	$ 10,474
General and administrative	10,753	8,780
Total operating expenses	25,499	19,254
Loss from operations	(25,499)	(19,254)
Other income, net
Interest income	(1,319)	(1,817)
Other expense, net	43	5
Total other income, net	(1,276)	(1,812)
Loss before income taxes	(24,223)	(17,442)
Income tax benefit	0	0
Net loss	$ (24,223)	$ (17,442)
Net loss per share, basic (in dollars per share)	$ (0.22)	$ (0.19)
Net loss per share, diluted (in dollars per share)	$ (0.22)	$ (0.19)
Weighted-average shares outstanding, basic (in shares)	112,222,789	92,964,048
Weighted-average shares outstanding, diluted (in shares)	112,222,789	92,964,048

Share-based Compensation

3 Months Ended

Mar. 31, 2026

Share-Based Payment Arrangement [Abstract]

Share-based Compensation

7. Share-based Compensation

On March 16, 2023, the Zura Bio Limited 2023 Equity Incentive Plan (the “Equity Incentive Plan”) was approved, became effective on March 19, 2023, and was amended on June 1, 2023. The Equity Incentive Plan allows for the grant of share options, both incentive and nonqualified share options; stock appreciation rights, alone or in conjunction with other awards; restricted shares awards (“RSAs”) and restricted share units (“RSUs”); incentive bonuses, which may be paid in cash, shares, or a combination thereof; and other share-based awards to employees, officers, non-employee directors and other service providers. The Company has granted share options, RSUs and RSAs that generally vest over four years and expire after 10 years.

The Class A Ordinary Shares issuable under the Equity Incentive Plan are subject to an annual increase on January 1st of each calendar year beginning on January 1, 2024, and ending on and including January 1, 2029, in accordance with the Equity Incentive Plan.

On March 16, 2023, the Zura Bio Limited 2023 Employee Stock Purchase Plan (the “ESPP”) was approved and became effective on March 19, 2023. The ESPP enables eligible employees of the Company and designated affiliates to purchase Class A Ordinary Shares at a discount of 15%. As of March 31, 2026, the Company has not activated its ESPP.

The Class A Ordinary Shares reserved for future issuances under the Equity Incentive Plan and the ESPP increased in accordance with the respective plans on January 1, 2026. As of March 31, 2026, a maximum of 20,573,023 Class A Ordinary Shares were authorized for issuance under the Equity Incentive Plan and the ESPP, collectively.

Equity Incentive Plan

Share Options

The fair value of Equity Incentive Plan share options are estimated on the date of grant using the Black-Scholes option pricing model. The Company lacks significant company-specific historical and implied volatility information. Therefore, it estimates its expected share volatility based on the historical volatility of a publicly traded set of peer companies. Due to the lack of historical exercise history, the expected term of the Company’s share options has been determined using the simplified method, averaging the vesting period and the contractual life of the share options granted. The risk-free interest rate is determined by reference to the U.S. Treasury yield curve in effect at the time of grant of the award for time periods

approximately equal to the expected term of the award. Expected dividend yield is zero based on the fact that the Company has never paid cash dividends and does not expect to pay any cash dividends in the foreseeable future.

The following weighted-average assumptions were used to estimate the fair value of the Equity Incentive Plan share options issued during the three months ended March 31, 2026 and 2025:


	For the Three Months Ended March 31,
	2026			2025
Share price	$	6.32		$	1.20
Expected volatility	103.8		%	99.7		%
Risk-free rate	4.0		%	4.1		%
Expected term (in years)	5.3			6.1
Expected dividend yield	0		%	0		%

The following table summarizes the Company’s share option activity for the three months ended March 31, 2026:


	Number of Options	Weighted Average Exercise Price (per share)		Weighted Average Remaining Contractual Life (Years)	Aggregate Intrinsic Value (in thousands)
Options outstanding as of December 31, 2025	16,463,011	$	2.40	8.2	$	48,866
Granted	3,571,435	$	6.32
Forfeited	(2,142,386)	$	2.58
Options outstanding as of March 31, 2026	17,892,060	$	3.16	7.7	$	52,323
Options vested and exercisable as of March 31, 2026	9,002,039	$	2.26	6.4	$	33,422

As of March 31, 2026, there was approximately $25.0 million of total unrecognized share-based compensation expense related to options granted to employees, executives, and directors that is expected to be recognized over a weighted average period of 2.9 years.

Included in options outstanding as of both March 31, 2026 and December 31, 2025 in the table above are 2,055,314 options to purchase Class A Ordinary Shares issued to certain directors, executives, and employees outside of the Equity Incentive Plan.

The weighted average grant date fair value of options granted during the three months ended March 31, 2026 and 2025 was $5.08 and $0.97, respectively.

Market-Based Share Options

On January 21, 2026, the Company granted 505,881 options to purchase Class A Ordinary Shares (the “CEO Option Award”) to the Chief Executive Officer. The CEO Option Award will vest in full on the first date upon which both of the following goals are achieved, subject to the CEO’s continued service through such date: (a) the Company’s completion of an equity raise above a specified amount prior to a specified date, which condition was satisfied by the completion of the February 2026 Equity Offering, and (b) the volume-weighted average price of a Class A ordinary share of the Company equals or exceeds a specified price over a period of 30 consecutive trading days, prior to December 31, 2030. These awards have an exercise price of $6.32 and become exercisable when vested and both conditions are satisfied. These awards expire 10 years from the date of grant. The fair value of these Market-Based Share Options were estimated using a Monte Carlo valuation method.

The following weighted-average assumptions were used at the grant date to determine the fair value of Company’s Market-Based Share Options granted during the three months ended March 31, 2026:


	For the Three Months Ended March 31,
	2026
Share price	$	6.32
Expected volatility	105.0		%
Risk-free rate	4.2		%
Expected term (in years)	4.9
Expected dividend yield	—		%

For the three months ended March 31, 2026 and 2025, the Company recorded expense related to Market-Based Share Options, at the grant date fair value, of $0.7 million and $0.2 million, respectively.

Restricted Share Units

The following table summarizes the Company’s RSU activity for the three months ended March 31, 2026:


	Number of RSUs	Weighted Average Grant Date Fair Value
Unvested RSUs outstanding as of December 31, 2025	583,282	$	5.99
Unvested RSUs outstanding as of March 31, 2026	583,282	$	5.99

As of March 31, 2026, there was approximately $2.0 million of total unrecognized share-based compensation expense related to RSUs granted to certain employees, executives, and directors under the Company’s Equity Incentive Plan that is expected to be recognized over a weighted average period of 1.2 years. For each of the three months ended March 31, 2026 and 2025, the Company recorded expense related to RSUs of $0.4 million, respectively.

Restricted Share Awards

The following table summarizes the Company’s RSA activity for the three months ended March 31, 2026:


	Number of RSAs	Weighted Average Grant Date Fair Value
Unvested RSAs outstanding as of December 31, 2025	249,997	$	8.16
Vested	(124,998)	8.16
Unvested RSAs outstanding as of March 31, 2026	124,999	$	8.16

As of March 31, 2026, there was approximately $1.0 million of total unrecognized share-based compensation expense related to RSAs granted to a certain director under the Company’s Equity Incentive Plan that is expected to be recognized over a weighted average period of 1.0 year. For each of the three months ended March 31, 2026 and 2025, the Company recorded expense related to RSAs of $0.3 million.

Equity Award Modification

On January 21, 2026 (the “Effective Date”), the Company and Rob Lisicki entered into an agreement in connection with Mr. Lisicki’s resignation which provided for an extension of the post-termination exercise period for Mr. Lisicki’s outstanding vested stock options to the earlier of (i) March 31, 2027 or (ii) the applicable expiration date of the applicable stock option. The agreement also provided for accelerated vesting of 25% of the shares underlying the option granted to

Mr. Lisicki on February 27, 2025 as of the Effective Date, which shares were originally scheduled to vest on February 27, 2026, subject to specified lock-up restrictions. All other unvested options outstanding as of the Effective Date were immediately forfeited. During the three months ended March 31, 2026, the Company recognized $1.5 million of share-based compensation expense related to this modification within general and administrative expense in the condensed consolidated statement of operations.

Share-based Compensation Expense

Share-based compensation expense for all equity arrangements for the three months ended March 31, 2026 and 2025 was as follows:


	For the Three Months Ended March 31,
	2026		2025
Research and development	$	569	$	518
General and administrative	4,439		3,126
Total share-based compensation expense	$	5,008	$	3,644

License Agreements	3 Months Ended
License Agreements	Mar. 31, 2026
Asset Acquisition [Abstract]
License Agreements	5. License Agreements 2023 Lilly License On April 26, 2023, ZB17 entered into a license agreement with Lilly (the “2023 Lilly License”) for an exclusive license to develop, manufacture and commercialize tibulizumab. The Company is obligated to make payments to Lilly (a) for 4 development milestone payments up to an aggregate of $155.0 million, and sales milestone payments up to an aggregate of $440.0 million based on respective thresholds of net sales of products developed from tibulizumab; and (b) over a multi-year period (twelve years, or upon the later expiration of regulatory exclusivity of tibulizumab in a country) for an annual earned royalty at a marginal royalty rate in the mid-single digits to low-double digits, with increasing royalty percentage rates depending on net sales in the respective calendar year, based on a percentage of sales within varying thresholds for a certain period of years (collectively, the “2023 Lilly Contingent Payments”). As of March 31, 2026, none of the 2023 Lilly Contingent Payments are due and accordingly will not be recorded in the Company’s financial statements until they are due. 2022 Lilly License On December 8, 2022, the Company’s consolidated subsidiary, Z33, entered into a license agreement with Lilly (the “2022 Lilly License”) pursuant to which Lilly granted Z33 an exclusive (even as to Lilly) license to develop, manufacture, and commercialize torudokimab. The Company is obligated to make payments to Lilly for (a) 10 commercial, development and regulatory milestone payments up to an aggregate of $155.0 million and sales milestone payments up to an aggregate of $440.0 million based on respective thresholds of net sales of products developed from the licensed compound, if any; and (b) an annual earned royalty at a marginal royalty rate in the mid-single to low-double digits, with increasing royalty percentage rates based on net sales in the respective calendar year, based on a percentage of sales within varying thresholds for a certain period of the year, if any year (collectively, the “2022 Lilly Contingent Payments”). The Company will account for these contingent milestone payments when they become due. As of March 31, 2026, none of the 2022 Lilly Contingent Payments are due and accordingly will not be recorded in the Company’s financial statements until they are due. Pfizer Agreement On March 22, 2022, the Company entered into a license agreement and a Series A-1 Subscription and Shareholder’s Agreement (collectively, the “Pfizer Agreement”) with Pfizer. Under the Pfizer Agreement, the Company acquired a license for crebankitug. The Company is obligated to make payments to Pfizer for (a) 11 remaining future development and regulatory milestone payments aggregating up to $69.0 million and sales milestone payments up to an aggregate of $525.0 million based on respective thresholds of net sales of products (developed from the licensed compound) (the “Products”), if any; and (b) an annual earned royalty at a marginal royalty rate in the mid-single digits to low double digits (less than 20%), based on thresholds of net sales of the Company’s Products, if any (collectively, the “Pfizer Contingent Payments”). Royalties are payable on a country-by-country basis for a certain period of years or upon the later expiration of regulatory exclusivity of the Company’s Products in a country. As of March 31, 2026, no Pfizer Contingent Payments are due and accordingly no Pfizer Contingent Payments will be recorded in the Company’s financial statements until they are due. Lonza License In July 2022, the Company entered into a license agreement (the “Lonza License”) with Lonza Sales AG (“Lonza”) for a worldwide non-exclusive license for Lonza’s gene expression system in exchange for varying considerations depending on a number of factors such as whether the Company enters further into manufacturing agreements with Lonza or with a third party, and whether the Company enters into sublicense agreements with third parties (including up to middle six-figure annual payments per sublicense upon commencement of a sublicense, as well as royalties of up to low-single digit percentages of net sales of certain products over a commercially standard double-digit multi-year term). The Lonza License will remain in effect until terminated. The Company is free to terminate the Lonza License at any time upon 60 days’ notice, with or without cause. Lonza may terminate the Lonza License for cause upon a breach by the Company or for other commercially standard reasons. Pursuant to the terms of the Lonza License, the Company has a license fee of $0.4 million due to Lonza annually in the fourth quarter as a result of manufacturing drug substance with a third party other than Lonza since 2023. WuXi Biologics License In July 2023, the Company entered into a cell line license agreement (the “Cell Line License Agreement”) with WuXi Biologics and its Affiliates (“WuXi Biologics”) for certain of WuXi Biologics’s know-how, cell line, and biological materials to manufacture, have manufactured, use, sell and import certain products produced through the use of the cell line licensed by WuXi Biologics under the Cell Line License Agreement (the “WuXi Biologics Licensed Products”). If the Company manufactures all of its commercial supplies of bulk drug product for WuXi Biologics Licensed Products with a manufacturer other than WuXi Biologics or its affiliates, the Company is required to make royalty payments to WuXi Biologics in an amount equal to a fraction of a single digit percentage of global net sales of WuXi Biologics Licensed Products manufactured by a third-party manufacturer (the “Royalty”). If the Company manufactures part of its commercial supplies of the WuXi Biologics Licensed Products with WuXi Biologics or its affiliates, then the Royalty will be reduced accordingly on a pro rata basis. The Cell Line License Agreement will continue indefinitely unless terminated (i) by the Company upon three months’ prior written notice and its payment of all undisputed amounts due to WuXi Biologics through the effective date of termination, (ii) by WuXi Biologics for a material breach by the Company that remains uncured for 30 days after written notice, or (iii) by WuXi Biologics if the Company fails to make a payment and such failure continues for 30 days after receiving notice of such failure. As of March 31, 2026, there are no payments currently due under the Cell Line License Agreement. Athanor Letter Agreement On December 29, 2025, the Company entered into a letter agreement with Athanor Capital, an exempted company incorporated under the laws of the Cayman Islands with limited liability (“Athanor”) (the “Athanor Agreement”), pursuant to which the Company issued to Athanor 8,657,402 Ordinary Shares (the “Athanor Shares”). Athanor is also entitled to piggyback registration rights pursuant to which Athanor has the right to include Athanor Shares in certain registered offerings by the Company or if the Company proposes to file a registration statement under the Securities Act of 1933, as amended, with respect to the registration of equity securities, as set forth in the Athanor Agreement. In addition, pursuant to the terms of the Athanor Agreement, the Company agreed to pay Athanor an upfront fee in an amount equal to $7.3 million within thirty days of execution of the Athanor Agreement and a one-time milestone payment in the amount of $25.0 million after the occurrence of the earliest of the following events: (i) the Company or ZB17 undergoes a Change of Control (as defined in the Athanor Agreement), (ii) the consummation by the Company or ZB17 of a sale of assets resulting in net proceeds in excess of $500.0 million, or (iii) First Indication Regulatory Approval (as defined in the Athanor Agreement). In addition, pursuant to the terms of the Athanor Agreement, the Company agreed to pay an amount equal to 2% of Net Sales (as defined in the Athanor Agreement) for the Product (as defined in the Athanor Agreement) to the extent such Net Sales (collectively, the “Net Sales Payments”) are the subject of a royalty payment under the 2023 Lilly License. The upfront fee was paid as of December 31, 2025. The Athanor Agreement contains representations, warranties and covenants by the parties in addition to the terms described above and shall remain in effect on a country-by-country basis until the expiration of the obligation to pay the Net Sales Payments.

Accounts Payable and Accrued Expenses (Tables)

3 Months Ended

Mar. 31, 2026

Accounts Payable and Accrued Liabilities, Current [Abstract]

Schedule of accounts payable and accrued expenses


	March 31, 2026		December 31, 2025
Accrued research and development costs	$	5,490	$	6,575
Accrued bonus	1,131		3,319
Accounts payable	2,083		1,279
Accrued professional fees	1,407		559
Other accrued expenses	1,634		678
Total accounts payable and accrued expenses	$	11,745	$	12,410

Share-based Compensation - Schedule of Company's Share Option Activity (Details) - Equity Incentive Plan 2023 - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2026	Dec. 31, 2025
Number of Options
Beginning balance (in shares)	16,463,011
Granted (in shares)	3,571,435
Forfeited (in shares)	(2,142,386)
Ending balance (in shares)	17,892,060	16,463,011
Options vested and exercisable	9,002,039
Weighted Average Exercise Price (per share)
Beginning balance (in dollars per share)	$ 2.40
Granted (in dollars per share)	6.32
Forfeited (in dollars per share)	2.58
Ending balance (in dollars per share)	3.16	$ 2.40
Options vested and exercisable (in dollars per share)	$ 2.26
Weighted Average Remaining Contractual Life (Years)
Options outstanding, Weighted Average Remaining Contractual Life (Years)	7 years 8 months 12 days	8 years 2 months 12 days
Options vested and exercisable, Weighted Average Remaining Contractual Life (Years)	6 years 4 months 24 days
Aggregate Intrinsic Value
Options outstanding, Aggregate Intrinsic Value	$ 52,323	$ 48,866
Options vested and exercisable, Aggregate Intrinsic Value	$ 33,422

Shareholders' Equity (Details) - USD ($) $ / shares in Units, $ in Millions		1 Months Ended
	Aug. 15, 2024	Feb. 28, 2026	Mar. 31, 2026	Dec. 31, 2025	Sep. 17, 2024
License Agreements
Class A ordinary shares authorized (in shares)			300,000,000	300,000,000
Class A ordinary shares, par value per share (in dollars per share)			$ 0.0001	$ 0.0001
Preferred shares authorized (in shares)			1,000,000
Preferred shares, par value per share (in dollars per share)			$ 0.0001
Aggregate sales price		$ 134.6
Pre-Funded Warrants
License Agreements
Sale of stock, price per share (in dollars per share)		$ 6.249
Warrants issued (in shares)		1,800,000
Exercise price of warrants (in dollars per share)		$ 0.001	$ 0.001	$ 0.001
Class of warrant or right, outstanding			29,295,396	27,495,396
Number of Class A ordinary shares upon exercise of each warrant	1
Notice period ( in days)	61 days
Pre-Funded Warrants \| Minimum
License Agreements
Percentage of shares outstanding immediately prior to or after giving effect to exercise of share exchange	4.99%
Pre-Funded Warrants \| Maximum
License Agreements
Percentage of shares outstanding immediately prior to or after giving effect to exercise of share exchange	9.99%
Percentage of shares outstanding immediately after giving effect to exercise of share exchange	19.99%
Common Class A
License Agreements
Class A ordinary shares, par value per share (in dollars per share)		$ 0.0001
Sale of stock, number of shares issued in transaction (in shares)		21,200,000
Sale of stock, price per share (in dollars per share)		$ 6.25
Common Class A \| Pre-Funded Warrants
License Agreements
Class A ordinary shares, par value per share (in dollars per share)		$ 6.249
Warrants issued (in shares)		1,800,000
Proceeds from sale of shares and warrants		$ 11.2
At The Market Offering
License Agreements
Aggregate amount of shares reserved			$ 114.0		$ 300.0
At The Market Offering \| Common Class A
License Agreements
Aggregate amount of shares reserved					$ 125.0
Over-Allotment Option \| Common Class A
License Agreements
Sale of stock, number of shares issued in transaction (in shares)		3,000,000

Fair Value Measurements

3 Months Ended

Mar. 31, 2026

Fair Value Disclosures [Abstract]

Fair Value Measurements

3. Fair Value Measurements

The Company measures certain financial assets and liabilities at fair value on a recurring basis. The Company determines fair value based upon the exit price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants, as determined by either the principal market or the most advantageous market. Inputs used in the valuation techniques to derive fair values are classified based on a three-level hierarchy. These levels are:

Level 1: Inputs are unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date;

Level 2: Inputs are observable, unadjusted quoted prices in active markets for similar assets or liabilities, unadjusted quoted prices for identical or similar assets or liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the related assets or liabilities; and

Level 3: Unobservable inputs that are significant to the measurement of the fair value of the assets or liabilities that are supported by little or no market data.

Financial instruments consist of cash and cash equivalents, prepaid and other current assets, and accounts payable and accrued expenses. The carrying values of the Company’s cash, prepaid and other current assets, and accounts payable and accrued expenses approximate their fair value due to the short-term maturity of these instruments.

The following table presents information about the Company’s financial assets and liabilities measured at fair value on a recurring basis as of March 31, 2026 and December 31, 2025, and the fair value hierarchy of the valuation techniques utilized.


	March 31, 2026
	Level 1		Level 2		Level 3		Total
Financial assets:
Cash equivalents	$	220,248	$	—	$	—	$	220,248


	December 31, 2025
	Level 1		Level 2		Level 3		Total
Financial assets:
Cash equivalents	$	106,310	$	—	$	—	$	106,310

There were no transfers into or out of Level 1, Level 2, or Level 3 during the three months ended March 31, 2026.

- 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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
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-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 107
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482078/820-10-55-107

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 100
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482078/820-10-55-100

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
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-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
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-Name Accounting Standards Codification
-Section 50
-Paragraph 6A
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-6A

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2E
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2E

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
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-Name Accounting Standards Codification
-Section 50
-Paragraph 6A
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-6A

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6A
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-6A

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6A
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-6A

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6A
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-6A

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
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-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
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-Name Accounting Standards Codification
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-Paragraph 2
-Subparagraph (g)
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-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 940
-SubTopic 820
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478119/940-820-50-1

+ Details

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Cash flows from operating activities
Net loss	$ (24,223)	$ (17,442)
Adjustments to reconcile net loss to net cash used in operating activities
Share-based compensation expense	5,008	3,644
Depreciation and amortization	16	9
Foreign exchange transaction loss	2	24
Loss on disposal of property and equipment	3	0
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	1,493	1,123
Accounts payable and accrued expenses	(1,222)	1,579
Net cash used in operating activities	(18,923)	(11,063)
Cash flows from investing activities
Purchase of property and equipment	(13)	(49)
Net cash used in investing activities	(13)	(49)
Cash flows from financing activities
Proceeds from issuance of Class A Ordinary Shares in connection with February 2026 Equity Offering, net of $8.0 million of underwriters’ fees and discounts	123,875	0
Proceeds from issuance of Pre-Funded Warrants in connection with February 2026 Equity Offering, net of $0.7 million of underwriters’ fees and discounts	11,248	0
Proceeds from exercise of stock options	0	90
Net cash provided by financing activities	135,123	5,183
Net increase (decrease) in cash and cash equivalents	116,187	(5,929)
Cash and cash equivalents, beginning of period	109,407	176,498
Cash and cash equivalents, ending of period	225,594	170,569
Supplemental Disclosure
Cash paid for taxes	0	0
Cash paid for interest	0	0
Supplemental Disclosure of Non-Cash Investing and Financing Activities
Purchase of property and equipment included in accounts payable and accrued expenses	5	0
Private Placement February 2026
Supplemental Disclosure of Non-Cash Investing and Financing Activities
Transaction costs for February 2026 Equity Offering included in accounts payable and accrued expenses	550	0
At The Market Offering
Cash flows from financing activities
Proceeds from issuance of Class A Ordinary Shares in connection with a sale under the ATM, net of $0.2 million of commissions	$ 0	$ 5,093

Condensed Consolidated Statements of Changes in Redeemable Noncontrolling Interest and Shareholders’ Equity (Unaudited) (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Subsidiary, Sale of Stock [Line Items]
Issuance of shares, transaction costs	$ 8.0
At The Market Offering
Subsidiary, Sale of Stock [Line Items]
Issuance of shares, transaction costs	$ 0.2	$ 0.2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2026	Dec. 31, 2025
Statement of Financial Position [Abstract]
Class A ordinary shares, par value per share (in dollars per share)	$ 0.0001	$ 0.0001
Class A ordinary shares authorized (in shares)	300,000,000	300,000,000
Class A ordinary shares issued (in shares)	94,880,710	73,680,710
Class A ordinary shares outstanding (in shares)	94,880,710	73,680,710

Summary of Significant Accounting Policies - Schedule of Net Loss Per Share (Details) - shares	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Summary of Significant Accounting Policies
Total	16,223,438	16,703,558
Shares issuable upon exercise of options to purchase Class A Ordinary Shares
Summary of Significant Accounting Policies
Total	15,525,157	13,593,638
Shares issuable upon exercise of Z33 Series Seed Preferred Shares Put Right
Summary of Significant Accounting Policies
Total	0	2,000,000
Shares issuable upon vesting of restricted share units
Summary of Significant Accounting Policies
Total	573,282	859,923
Restricted share awards
Summary of Significant Accounting Policies
Total	124,999	249,997

Summary of Significant Accounting Policies - Segments (Details) $ in Millions	1 Months Ended	3 Months Ended
	Apr. 30, 2025 USD ($)	Mar. 31, 2026 segment claim
Accounting Policies [Abstract]
Number of reportable segments		1
Number of operating segments		1
Number of claims filed \| claim		2
Research and development inventive credit \| $	$ 1.0

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	Mar. 31, 2026
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

Summary of Significant Accounting Policies - Schedule of Segment Reporting Information, by Segment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Segment Reporting Information [Line Items]
Research and development	$ 14,746	$ 10,474
Net loss	(24,223)	(17,442)
Reportable Segment
Segment Reporting Information [Line Items]
Stock-based compensation	5,008	3,644
Other segment items	(1,260)	(1,803)
Net loss	24,223	17,442
Research and development \| Reportable Segment
Segment Reporting Information [Line Items]
Wages and benefits	2,603	1,466
Unallocated research and development expenses	573	456
Research and development \| Reportable Segment \| Tibulizumab SSc program
Segment Reporting Information [Line Items]
Research and development	3,200	2,763
Research and development \| Reportable Segment \| Tibulizumab HS program
Segment Reporting Information [Line Items]
Research and development	4,701	1,274
Research and development \| Reportable Segment \| Tibulizumab general
Segment Reporting Information [Line Items]
Research and development	2,929	3,706
Research and development \| Reportable Segment \| Additional product candidates (torudokimab and crebankitug)
Segment Reporting Information [Line Items]
Research and development	171	291
General and administrative \| Reportable Segment
Segment Reporting Information [Line Items]
Wages and benefits	2,686	2,591
Other general and administrative expenses	$ 3,612	$ 3,054

Condensed Consolidated Statements of Changes in Redeemable Noncontrolling Interest and Shareholders’ Equity (Unaudited) - USD ($) $ in Thousands	Total	At The Market Offering	Pre-Funded Warrants	Class A Ordinary Shares	Class A Ordinary Shares At The Market Offering	Additional Paid-in Capital	Additional Paid-in Capital At The Market Offering	Accumulated Deficit	Noncontrolling Interest
Beginning Balance at Dec. 31, 2024	$ 11,663
Ending Balance at Mar. 31, 2025	11,663
Beginning Balance (in shares) at Dec. 31, 2024				65,297,530
Beginning Balance at Dec. 31, 2024	148,356			$ 7		$ 302,705		$ (155,897)	$ 1,541
Increase (Decrease) in Stockholders' Deficit
Issuance of Class A ordinary shares (in shares)					3,000,000
Issuance of Class A ordinary shares (in shares)		$ 5,093					$ 5,093
Stock option exercises and restricted stock unit releases (in Shares)				77,468
Stock option exercises and restricted stock unit releases	90					90
Share-based compensation	3,644					3,644
Net loss	(17,442)							(17,442)
Ending Balance (in Shares) at Mar. 31, 2025				68,374,998
Ending Balance at Mar. 31, 2025	139,741			$ 7		311,532		(173,339)	1,541
Increase (Decrease) in Stockholders' Deficit
Issuance of shares, transaction costs		200
Beginning Balance at Dec. 31, 2025	0
Ending Balance at Mar. 31, 2026	$ 0
Beginning Balance (in shares) at Dec. 31, 2025	73,680,710			73,680,710
Beginning Balance at Dec. 31, 2025	$ 101,538			$ 7		326,078		(224,547)	0
Increase (Decrease) in Stockholders' Deficit
Issuance of Class A ordinary shares (in shares)					21,200,000
Issuance of Class A ordinary shares (in shares)		123,371		$ 2			$ 123,369
Adjustments to Additional Paid in Capital, Warrant Issued	11,202					11,202
Share-based compensation	5,008					5,008
Net loss	$ (24,223)							(24,223)
Ending Balance (in Shares) at Mar. 31, 2026	94,880,710			94,880,710
Ending Balance at Mar. 31, 2026	$ 216,896			$ 9		$ 465,657		$ (248,770)	$ 0
Increase (Decrease) in Stockholders' Deficit
Issuance of shares, transaction costs	$ 8,000	$ 200	$ 700		$ 8,500

License Agreements (Details) - USD ($)			3 Months Ended
License Agreements (Details) - USD ($)	Dec. 29, 2025	Mar. 22, 2022	Dec. 31, 2025	Mar. 31, 2026
Anthor
License Agreements
Percentage of net sales	2.00%
Wuxi Biologics License
License Agreements
Amount of license costs payable				$ 0
Athanor Letter Agreement \| Anthor
License Agreements
Athanor agreement, upfront fee	$ 7,300,000
Upfront fee payment period	30 days
One-time milestone payment on achievement of conditions	$ 25,000,000.0
Minimum net proceeds from sale of assets for one-time milestone payment	500,000,000.0
Athanor Letter Agreement \| Anthor \| Common Class A
License Agreements
Stock issued during period, value, new issues (in shares)	$ 8,657,402
Research and development \| Lonza milestone payment
License Agreements
Annual milestone payment, due and payable			$ 400,000
Agreement with Pfizer
License Agreements
Maximum amount of development and regulatory milestone payments		$ 69,000,000.0
Maximum amount of sales milestone payments		$ 525,000,000.0
Maximum annual earned royalty at a marginal royalty rate		20.00%
Amount of license costs payable				$ 0

Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2026

Fair Value Disclosures [Abstract]

Schedule of financial assets and liabilities measured at fair value on a recurring basis


	March 31, 2026
	Level 1		Level 2		Level 3		Total
Financial assets:
Cash equivalents	$	220,248	$	—	$	—	$	220,248


	December 31, 2025
	Level 1		Level 2		Level 3		Total
Financial assets:
Cash equivalents	$	106,310	$	—	$	—	$	106,310