Nature of Operations and Basis of Presentation	6 Months Ended
Jun. 30, 2026
Accounting Policies [Abstract]
Nature of Operations and Basis of Presentation	1. Nature of Operations and Basis of Presentation Organization Climb Bio, Inc. (the Company) is a clinical-stage biotechnology company developing therapeutics for patients with immune-mediated diseases. The Company’s pipeline includes budoprutug and CLYM116. Budoprutug is an anti-CD19 monoclonal antibody designed to treat a broad range of B-cell mediated diseases. The Company is currently developing budoprutug for the treatment of primary membranous nephropathy, immune thrombocytopenia, and systemic lupus erythematosus. CLYM116 is an anti-APRIL (A PRoliferation-Inducing Ligand) monoclonal antibody currently being developed for the treatment of immunoglobulin A nephropathy. The Company was incorporated on October 18, 2018 in Delaware, and its corporate headquarters is in Massachusetts. 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, development by competitors of new technological innovations, protection of proprietary technology, dependence on key personnel, reliance on single-source suppliers and manufacturers, availability of raw materials, patentability of the Company’s product candidates and processes and clinical efficacy and safety of the Company’s product candidates, compliance with government regulations and the need to obtain additional financing to fund operations. Budoprutug, CLYM116, or any product candidate the Company may develop will require significant additional research and development efforts, including extensive nonclinical studies, clinical trials, and regulatory approval, prior to commercialization. These efforts will require significant amounts of additional capital, adequate personnel infrastructure and extensive compliance and reporting. There can be no assurance that any future research and development will be successfully completed, that adequate protection for the Company’s intellectual property will be obtained or maintained, that any product candidate developed will obtain necessary government regulatory approval or that any approved products will be commercially viable. Even if any future product development efforts are successful, it is uncertain when, if ever, the Company will generate revenue from product sales. The Company operates in an environment of rapid technological change and substantial competition from other pharmaceutical and biotechnology companies. In addition, the Company is dependent upon the services of its employees, consultants and other third parties. Basis of Presentation and Principles of Consolidation The accompanying unaudited interim condensed consolidated financial statements reflect the operations of the Company and its wholly owned subsidiaries. Intercompany transactions and balances have been eliminated in consolidation. The accompanying unaudited interim condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States (U.S. GAAP) and in accordance with the rules and regulations of the U.S. Securities and Exchange Commission (SEC) for Quarterly Reports on Form 10-Q. Any reference in these notes to applicable guidance is meant to refer to the authoritative U.S. GAAP as found in the Accounting Standards Codification (ASC) and Accounting Standards Update (ASU) of the Financial Accounting Standards Board (FASB). The accompanying unaudited interim condensed consolidated financial statements as of June 30, 2026 and for the three and six months ended June 30, 2026 and 2025, are unaudited. The consolidated balance sheet as of December 31, 2025 was derived from the audited financial statements as of and for the year ended December 31, 2025, but does not include all disclosures required by U.S. GAAP. The unaudited interim condensed consolidated financial statements have been prepared on a basis consistent with the audited annual financial statements as of and for the year ended December 31, 2025, and, in the opinion of management, reflect all adjustments, consisting solely of normal recurring adjustments, necessary for the fair statement of the Company’s financial position as of June 30, 2026, the condensed results of its operations for the three and six months ended June 30, 2026 and 2025, and its cash flows for the six months ended June 30, 2026 and 2025. The financial data and other information disclosed in these notes related to the three and six months ended June 30, 2026 and 2025 are also unaudited. The condensed results of operations for the three and six months ended June 30, 2026 are not necessarily indicative of the results to be expected for the full year ending December 31, 2026 or any other period. These unaudited interim condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements included in the Company’s Annual Report on Form 10-K filed with the SEC on March 5, 2026 (Annual Report). Liquidity Since inception, the Company has experienced recurring losses from operations and generated negative cash flows from operations. During the three and six months ended June 30, 2026, the Company incurred a net loss of $13.5 million and $27.2 million, respectively, and for the six months ended June 30, 2026, the Company had negative operating cash flows of $24.9 million. The Company has an accumulated deficit of $316.9 million as of June 30, 2026 and expects to incur additional losses from operations in the future until such time, if ever, that the Company can generate significant sales of its product candidates currently in development. Since inception, the Company has funded its operations with proceeds from the sale and issuance of shares of its redeemable convertible preferred stock, its initial public offering, and the sale and issuance of shares in private placements of shares of the Company’s common stock and pre-funded warrants to certain institutional investors. Cash, cash equivalents and marketable securities were $239.2 million as of June 30, 2026. Based on its current operating plan, the Company expects this balance will be sufficient to meet its projected operating requirements for at least the next twelve months from the filing date of these unaudited condensed consolidated financial statements. The Company anticipates that it will need to raise substantial financing in the future to fund its operations. The Company may finance future cash needs through the sale of equity, debt financings or other capital sources, which could include income from collaborations, strategic partnerships or other strategic arrangements. There are no assurances that the Company will be able to raise sufficient amounts of funding in the future on acceptable terms, or at all.

Nature of Operations and Basis of Presentation

6 Months Ended

Jun. 30, 2026

Nature of Operations and Basis of Presentation

1. Nature of Operations and Basis of Presentation

Organization

Climb Bio, Inc. (the Company) is a clinical-stage biotechnology company developing therapeutics for patients with immune-mediated diseases. The Company’s pipeline includes budoprutug and CLYM116. Budoprutug is an anti-CD19 monoclonal antibody designed to treat a broad range of B-cell mediated diseases. The Company is currently developing budoprutug for the treatment of primary membranous nephropathy, immune thrombocytopenia, and systemic lupus erythematosus. CLYM116 is an anti-APRIL (A PRoliferation-Inducing Ligand) monoclonal antibody currently being developed for the treatment of immunoglobulin A nephropathy. The Company was incorporated on October 18, 2018 in Delaware, and its corporate headquarters is in Massachusetts.

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, development by competitors of new technological innovations, protection of proprietary technology, dependence on key personnel, reliance on single-source suppliers and manufacturers, availability of raw materials, patentability of the Company’s product candidates and processes and clinical efficacy and safety of the Company’s product candidates, compliance with government regulations and the need to obtain additional financing to fund operations. Budoprutug, CLYM116, or any product candidate the Company may develop will require significant additional research and development efforts, including extensive nonclinical studies, clinical trials, and regulatory approval, prior to commercialization. These efforts will require significant amounts of additional capital, adequate personnel infrastructure and extensive compliance and reporting.

There can be no assurance that any future research and development will be successfully completed, that adequate protection for the Company’s intellectual property will be obtained or maintained, that any product candidate developed will obtain necessary government regulatory approval or that any approved products will be commercially viable. Even if any future product development efforts are successful, it is uncertain when, if ever, the Company will generate revenue from product sales. The Company operates in an environment of rapid technological change and substantial competition from other pharmaceutical and biotechnology companies. In addition, the Company is dependent upon the services of its employees, consultants and other third parties.

Basis of Presentation and Principles of Consolidation

The accompanying unaudited interim condensed consolidated financial statements reflect the operations of the Company and its wholly owned subsidiaries. Intercompany transactions and balances have been eliminated in consolidation. The accompanying unaudited interim condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States (U.S. GAAP) and in accordance with the rules and regulations of the U.S. Securities and Exchange Commission (SEC) for Quarterly Reports on Form 10-Q. Any reference in these notes to applicable guidance is meant to refer to the authoritative U.S. GAAP as found in the Accounting Standards Codification (ASC) and Accounting Standards Update (ASU) of the Financial Accounting Standards Board (FASB).

The accompanying unaudited interim condensed consolidated financial statements as of June 30, 2026 and for the three and six months ended June 30, 2026 and 2025, are unaudited. The consolidated balance sheet as of December 31, 2025 was derived from the audited financial statements as of and for the year ended December 31, 2025, but does not include all disclosures required by U.S. GAAP. The unaudited interim condensed consolidated financial statements have been prepared on a basis consistent with the audited annual financial statements as of and for the year ended December 31, 2025, and, in the opinion of management, reflect all adjustments, consisting solely of normal recurring adjustments, necessary for the fair statement of the Company’s financial position as of June 30, 2026, the condensed results of its operations for the three and six months ended June 30, 2026 and 2025, and its cash flows for the six months ended June 30, 2026 and 2025. The financial data and other information disclosed in these notes related to the three and six months ended June 30, 2026 and 2025 are also unaudited. The condensed results of operations for the three and six months ended June 30, 2026 are not necessarily indicative of the results to be expected for the full year ending December 31, 2026 or any other period. These unaudited interim condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements included in the Company’s Annual Report on Form 10-K filed with the SEC on March 5, 2026 (Annual Report).

Liquidity

Since inception, the Company has experienced recurring losses from operations and generated negative cash flows from operations. During the three and six months ended June 30, 2026, the Company incurred a net loss of $13.5 million and $27.2 million, respectively, and for the six months ended June 30, 2026, the Company had negative operating cash flows of $24.9 million. The Company has an accumulated deficit of $316.9 million as of June 30, 2026 and expects to incur additional losses from operations in the future until such time, if ever, that the Company can generate significant sales of its product candidates currently in development.

Since inception, the Company has funded its operations with proceeds from the sale and issuance of shares of its redeemable convertible preferred stock, its initial public offering, and the sale and issuance of shares in private placements of shares of the Company’s common stock and pre-funded warrants to certain institutional investors. Cash, cash equivalents and marketable securities were $239.2 million as of June 30, 2026. Based on its current operating plan, the Company expects this balance will be sufficient to meet its projected operating requirements for at least the next twelve months from the filing date of these unaudited condensed consolidated financial statements. The Company anticipates that it will need to raise substantial financing in the future to fund its operations. The Company may finance future cash needs through the sale of equity, debt financings or other capital sources, which could include income from collaborations, strategic partnerships or other strategic arrangements. There are no assurances that the Company will be able to raise sufficient amounts of funding in the future on acceptable terms, or at all.