Climb Bio (CLYM) investor relations material

Strategic Focus and Pipeline Overview

• Focused on developing differentiated monoclonal antibodies targeting validated B-cell pathways for immune-mediated diseases, with a high bar for clinical and commercial potential.

• Lead program BDO PROTEG is advancing in multiple indications, with all four clinical trials actively enrolling.

• Climb 116 (CLYM116), in-licensed from Mabwell/Mabworks, is positioned as a complementary asset with global rights outside Greater China and is expected to enter clinical trials later this year.

IgA Nephropathy Landscape and Market Opportunity

• IgA nephropathy is a leading cause of end-stage renal disease, affecting approximately 170,000 patients in the US, with a $10-20B market opportunity.

• Disease progression is often asymptomatic, requiring lifelong management and highlighting the need for safe, effective, and durable therapies.

• New guidelines recommend earlier treatment initiation and stricter proteinuria targets, expanding the treatable population.

• Regulatory pathways for accelerated approval are established, with proteinuria reduction as a surrogate endpoint.

Scientific Rationale, Preclinical Data, and Differentiation

• APRIL is a validated target in IgA nephropathy, central to disease pathogenesis, and anti-APRIL therapies have shown efficacy in reducing proteinuria.

• Climb 116/CLYM116 is a next-generation anti-APRIL sweeper antibody, engineered for high-affinity, pH-dependent binding, efficient recycling, and enhanced APRIL elimination.

• Preclinical data in non-human primates show CLYM116 achieves a 2-3x longer half-life and deeper, more durable IgA reduction than first-generation agents like sibecrilimumab.

• Subcutaneous formulation offers high bioavailability (~85%), favorable tolerability, and potential for at-home dosing.