R&D Spotlight: CLYM116 and the IgAN Opportunity SEPTEMBER 29, 2025 © 2025 Climb Bio 1 Forward Looking Statements This presentation contains "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995, including without limitation statements regarding: future expectations, plans and prospects for Climb Bio, Inc. ("Climb Bio"); expectations regarding the therapeutic benefits, clinical potential and clinical development of budoprutug and CLYM116; the trial design for ...

Core Insights - Climb Bio, Inc. is advancing its clinical pipeline with ongoing trials for budoprutug in immune thrombocytopenia (ITP) and systemic lupus erythematosus (SLE), and plans to initiate a trial for primary membranous nephropathy (pMN) soon [1][3][4] - The company has a strong financial position, with cash reserves expected to fund operations through 2027 [1][10] Budoprutug Program Updates - Budoprutug, an anti-CD19 monoclonal antibody, is currently in Phase 1b/2a trials for ITP and SLE, with enrollment ongoing [6][12] - The pMN Phase 2 trial is set to begin in the coming weeks, focusing on safety and preliminary efficacy [6][12] - A subcutaneous formulation of budoprutug has shown high bioavailability and favorable tolerability in non-clinical studies, with a Phase 1 trial expected to start shortly [1][6] CLYM116 Program Updates - CLYM116, an anti-APRIL monoclonal antibody, is progressing towards clinical development for IgA nephropathy (IgAN), with an IND or CTA submission anticipated in the second half of 2025 [5][14] - An investor event is planned for September 2025 to present new preclinical data on CLYM116 [1][5] Corporate Updates - Edgar D. Charles, M.D., MSc has been appointed as Chief Medical Officer, bringing over 20 years of experience in immunology-focused pharmaceutical development [8] - The company reported a net loss of $8.7 million for the second quarter of 2025, compared to a loss of $54.9 million in the same period of 2024 [10][19] Financial Highlights - As of June 30, 2025, Climb Bio had cash, cash equivalents, and marketable securities totaling $187.4 million [10][17] - Research and development expenses for the second quarter of 2025 were $6.6 million, significantly higher than $1.0 million in the same period of 2024 [10][19]

Core Insights - Climb Bio, Inc. has appointed Dr. Edgar D. Charles as Chief Medical Officer and Cindy J. Driscoll as Senior Vice President, Finance, enhancing its leadership team at a crucial time for the company [1][2] Leadership Appointments - Dr. Charles brings over 20 years of experience in immunology-focused pharmaceutical development, having previously held significant roles at Bristol Myers Squibb, where he led the development of various therapeutic candidates [2][3] - Cindy Driscoll has over two decades of experience in financial and administrative functions within the biopharma sector, previously serving as Senior Vice President of Finance at HC Bioscience [2][4] Clinical Development Focus - The company is focused on advancing its clinical studies for budoprutug and CLYM116, with Dr. Charles emphasizing the therapeutic potential of budoprutug in treating serious diseases where B cells are central to pathology [4][7] - Budoprutug is an anti-CD19 monoclonal antibody that has shown promise in B cell depletion, while CLYM116 is an anti-APRIL monoclonal antibody currently in IND-enabling studies for IgA nephropathy [7] Inducement Equity Awards - Climb Bio has granted inducement equity awards to Dr. Charles and Ms. Driscoll, including stock options to purchase 600,000 and 200,000 shares of common stock, respectively, with an exercise price of $1.20 per share [5][6]