Business Description

Note 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. On June 27, 2024, the Company completed its acquisition of Tenet Medicines, Inc. (the Acquisition). In connection with the closing of the Acquisition, the Company issued and sold 31,238,282 shares of its common stock at a price of $ 3.84 per share in a private placement to several accredited institutional investors (the Private Placement). The Company received aggregate gross proceeds from the Private Placement of approximately $ 120.0 million, before deducting offering costs of $ 0.3 million (see Note 3). On January 8, 2025, the Company entered into a technology transfer and exclusive license agreement (the Mabworks Agreement) with Beijing Mabworks Biotech Co., Ltd. (Mabworks), for rights to develop and commercialize CLYM116 for all indications worldwide outside of mainland China, Hong Kong, Macau, and Taiwan (Greater China) (see Note 8). 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 consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States (U.S. GAAP). 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 consolidated financial statements reflect the operations of the Company and its wholly owned subsidiaries. Intercompany transactions and balances have been eliminated in consolidation. Liquidity Since inception, the Company has experienced recurring losses from operations and generated negative cash flows from operations. The Company has an accumulated deficit of $ 289.7 million as of December 31, 2025 and expects to incur additional losses from operations in the future.…