Climb Bio (CLYM) Wells Fargo 21st Annual Healthcare Conference summary

Program overviews and strategic focus

• Developing two co-lead antibody programs targeting immune-mediated diseases: budoprutug (anti-CD19) and CLYM116 (APRIL-only sweeper antibody).

• Budoprutug is in phase II for pMN, phase I-B for ITP and SLE, showing broad potential across B cell-mediated diseases.

• CLYM116 is advancing in IgA nephropathy (IgAN) with a best-in-class 12-week dosing profile and clean safety data.

• Multiple data readouts are expected in 2024 and 2025, with pivotal trials planned for both assets.

• Exploring expansion of APRIL asset into additional autoimmune indications.

CLYM116 (APRIL-only antibody) in IgAN

• Sweeper mechanism enables pH-dependent APRIL binding, degradation, and antibody recycling, avoiding TMDD seen in competitors.

• Achieves >90% APRIL suppression for 10 weeks and ~75% at week 12 with 320 mg/mL; 400 mg/mL maintenance dose planned.

• Demonstrates deep IgA and Gd-IgA1 reduction, correlating with proteinuria reduction and eGFR stabilization.

• No significant immunogenicity or tolerability issues observed at higher doses; clean safety profile without hypogammaglobulinemia.

• Phase II ongoing, with phase III pivotal trial targeted for next year; commercial opportunity estimated at $20B+ in the US.

Budoprutug (anti-CD19 antibody) in pMN, ITP, and SLE

• Targets B cell lineage including plasmablasts, offering deeper depletion than anti-CD20 therapies.

• Phase I-B in pMN showed 60% complete renal response vs. 36% for obinutuzumab; durable responses seen after two doses.

• ITP cohort at 250 mg showed >50% durable platelet response, exceeding current therapies; higher dose data expected by year end.

• SLE program is exploratory, with initial data at low doses in 2024 and therapeutic dose data in 2025; partnership considered for broader SLE development.

• Subcutaneous formulation matches IV in B cell depletion, offering future flexibility in administration.