Summary of significant accounting policies (Policies)	3 Months Ended
Mar. 31, 2026
Accounting Policies [Abstract]
Risks and uncertainties	Risks and uncertainties The Company is subject to risks and uncertainties common to early-stage companies in the biotechnology industry, including, but not limited to, the outcome of clinical trials, development by competitors of new technological innovations, dependence on key personnel, protection of proprietary technologies, compliance with government regulations, ability to secure additional capital to fund operations, and potential delays associated with the Company’s anticipated and planned trials. There can be no assurance that the Company will be able to successfully complete the development of, or receive regulatory approval for, any products developed, and if approved, that any products will be commercially viable. Any products resulting from the Company’s current research and development efforts will require significant additional research and development, including extensive preclinical and clinical testing and regulatory approval prior to commercialization. These efforts will require significant amounts of additional capital, adequate personnel, infrastructure, and extensive compliance reporting capabilities. The Company has not generated any revenue from the sale of any products to date. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will realize significant revenue from product sales.
Reverse Stock Split	Reverse Stock Split On January 2, 2026, the Company effected a 1-for-3.8044 reverse stock split of its issued and outstanding common stock, which also resulted in a proportional adjustment to the conversion price for each series of its redeemable convertible preferred stock, and to the exercise prices and number of outstanding stock options. The par value and authorized number of shares of common stock and redeemable convertible preferred stock were not adjusted as a result. All share and per share amounts for all periods presented in the condensed consolidated financial statements and notes thereto have been retroactively adjusted to reflect the effect of the reverse stock split.
Initial Public Offering	Initial Public Offering In January 2026, the Company completed its initial public offering ("IPO"), in which the Company sold an aggregate of 20,297,500 shares of its common stock at a public offering price of $18.00 per share, including 2,647,500 shares pursuant to the full exercise of the underwriters' option to purchase additional shares, resulting in aggregate net proceeds of approximately $334.4 million, after deducting underwriter discounts, commissions and other offering expenses incurred through March 31, 2026. Immediately prior to the closing of the IPO, the Company's outstanding redeemable convertible preferred stock automatically converted into 32,184,389 shares of common stock and 1,872,829 shares of Class A non-voting common stock. Following the closing of the IPO, no shares of redeemable convertible preferred stock were outstanding. In connection with the closing of the IPO, the Company's certificate of incorporation was amended and restated to authorize 480,000,000 shares of common stock, par value $0.0001 per share, 10,000,000 shares of Class A common stock, par value $0.0001 per share and 10,000,000 shares of undesignated preferred stock, par value $0.0001 per share.
Liquidity	Liquidity In accordance with Accounting Standards Update (“ASU”) 2014-15, Disclosure of Uncertainties About an Entity’s Ability to Continue as a Going Concern (Subtopic 205-40), the Company has evaluated whether there are conditions and events that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date the condensed consolidated financial statements are issued. The accompanying condensed consolidated financial statements have been prepared on a going-concern basis, which contemplates the realization of assets and satisfaction of liabilities in the normal course of business. The Company has incurred losses since inception, including net losses of $18.3 million and $15.0 million for the three months ended March 31, 2026 and 2025, respectively. As of March 31, 2026, the Company had an accumulated deficit of $174.9 million. The Company has evaluated whether there are certain conditions and events, considered in the aggregate, that raise substantial doubt about the Company's ability to continue as a going concern within the twelve months after the date that these condensed consolidated financial statements are issued. The Company believes that its existing cash, cash equivalents and marketable securities of $538.5 million as of March 31, 2026 will be sufficient to allow the Company to fund operations at least twelve months from the date that the financial statements are issued.
Unaudited interim financial information	Unaudited interim financial information The accompanying condensed consolidated balance sheet as of March 31, 2026, and the condensed consolidated statements of operations and comprehensive loss, condensed consolidated statements of redeemable convertible preferred stock and stockholders’ equity (deficit) and condensed consolidated statements of cash flows for the three months ended March 31, 2026 and 2025 are unaudited. The condensed consolidated interim financial statements have been prepared on the same basis as the December 31, 2025 and 2024 audited annual financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments necessary for the fair presentation of the Company’s financial position as of March 31, 2026. The results for the three months ended March 31, 2026 are not necessarily indicative of results to be expected for the year ending December 31, 2026, or for any other subsequent period.
Recent accounting pronouncements not yet adopted	Recent accounting pronouncements not yet adopted In November 2024, the FASB issued ASU No. 2024-03, Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures, ("ASU 2024-03"). ASU 2024-3 requires disclosure of additional information about specific expense categories in the notes to the financial statements on an interim and annual basis. The standard is effective for fiscal years beginning after December 15, 2026, and for interim periods beginning after December 15, 2027, with prospective or retrospective application and early adoption permitted. The Company is currently evaluating the disclosure requirements related to this new standard.
Basis of presentation and consolidation	Basis of presentation and consolidation The accompanying condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). The accompanying condensed consolidated financial statements include the accounts of the Company’s wholly-owned subsidiary, Aktis Security Corporation. All intercompany balances and transactions have been eliminated in consolidation. Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification (“ASC”) and ASUs of the Financial Accounting Standards Board (“FASB”).

Summary of significant accounting policies (Policies)

3 Months Ended

Mar. 31, 2026

The Company is subject to risks and uncertainties common to early-stage companies in the biotechnology industry, including, but not limited to, the outcome of clinical trials, development by competitors of new technological innovations, dependence on key personnel, protection of proprietary technologies, compliance with government regulations, ability to secure additional capital to fund operations, and potential delays associated with the Company’s anticipated and planned trials.

There can be no assurance that the Company will be able to successfully complete the development of, or receive regulatory approval for, any products developed, and if approved, that any products will be commercially viable. Any products resulting from the Company’s current research and development efforts will require significant additional research and development, including extensive preclinical and clinical testing and regulatory approval prior to commercialization. These efforts will require significant amounts of additional capital, adequate personnel, infrastructure, and extensive compliance reporting capabilities. The Company has not generated any revenue from the sale of any products to date. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will realize significant revenue from product sales.

Reverse Stock Split

On January 2, 2026, the Company effected a 1-for-3.8044 reverse stock split of its issued and outstanding common stock, which also resulted in a proportional adjustment to the conversion price for each series of its redeemable convertible preferred stock, and to the exercise prices and number of outstanding stock options. The par value and authorized number of shares of common stock and redeemable convertible preferred stock were not adjusted as a result. All share and per share amounts for all periods presented in the condensed consolidated financial statements and notes thereto have been retroactively adjusted to reflect the effect of the reverse stock split.

Initial Public Offering

In January 2026, the Company completed its initial public offering ("IPO"), in which the Company sold an aggregate of 20,297,500 shares of its common stock at a public offering price of $18.00 per share, including 2,647,500 shares pursuant to the full exercise of the underwriters' option to purchase additional shares, resulting in aggregate net proceeds of approximately $334.4 million, after deducting underwriter discounts, commissions and other offering expenses incurred through March 31, 2026. Immediately prior to the closing of the IPO, the Company's outstanding redeemable convertible preferred stock automatically converted into 32,184,389 shares of common stock and 1,872,829 shares of Class A non-voting common stock. Following the closing of the IPO, no shares of redeemable convertible preferred stock were outstanding.

In connection with the closing of the IPO, the Company's certificate of incorporation was amended and restated to authorize 480,000,000 shares of common stock, par value $0.0001 per share, 10,000,000 shares of Class A common stock, par value $0.0001 per share and 10,000,000 shares of undesignated preferred stock, par value $0.0001 per share.

Liquidity

In accordance with Accounting Standards Update (“ASU”) 2014-15, Disclosure of Uncertainties About an Entity’s Ability to Continue as a Going Concern (Subtopic 205-40), the Company has evaluated whether there are conditions and events that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date the condensed consolidated financial statements are issued. The accompanying condensed consolidated financial statements have been prepared on a going-concern basis, which contemplates the realization of assets and satisfaction of liabilities in the normal course of business.

The Company has incurred losses since inception, including net losses of $18.3 million and $15.0 million for the three months ended March 31, 2026 and 2025, respectively. As of March 31, 2026, the Company had an accumulated deficit of $174.9 million.

The Company has evaluated whether there are certain conditions and events, considered in the aggregate, that raise substantial doubt about the Company's ability to continue as a going concern within the twelve months after the date that these condensed consolidated financial statements are issued. The Company believes that its existing cash, cash equivalents and marketable securities of $538.5 million as of March 31, 2026 will be sufficient to allow the Company to fund operations at least twelve months from the date that the financial statements are issued.

Unaudited interim financial information

The accompanying condensed consolidated balance sheet as of March 31, 2026, and the condensed consolidated statements of operations and comprehensive loss, condensed consolidated statements of redeemable convertible preferred stock and stockholders’ equity (deficit) and condensed consolidated statements of cash flows for the three months ended March 31, 2026 and 2025 are unaudited. The condensed consolidated interim financial statements have been prepared on the same basis as the December 31, 2025 and 2024 audited annual financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments necessary for the fair presentation of the Company’s financial position as of March 31, 2026. The results for the three months ended March 31, 2026 are not necessarily indicative of results to be expected for the year ending December 31, 2026, or for any other subsequent period.

Recent accounting pronouncements not yet adopted

In November 2024, the FASB issued ASU No. 2024-03, Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures, ("ASU 2024-03"). ASU 2024-3 requires disclosure of additional information about specific expense categories in the notes to the financial statements on an interim and annual basis. The standard is effective for fiscal years beginning after December 15, 2026, and for interim periods beginning after December 15, 2027, with prospective or retrospective application and early adoption permitted. The Company is currently evaluating the disclosure requirements related to this new standard.

Basis of presentation and consolidation

The accompanying condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). The accompanying condensed consolidated financial statements include the accounts of the Company’s wholly-owned subsidiary, Aktis Security Corporation. All intercompany balances and transactions have been eliminated in consolidation. Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification (“ASC”) and ASUs of the Financial Accounting Standards Board (“FASB”).