CLYM — A Derisked Dual-Asset B-Cell Pipeline of Anti-CD19 mAb and Differentiated Anti-APRIL "Sweeper" with Nephrology Emphasis; Initiate at Buy with $35 PT

Research evidence excerpt

CLYM — A Derisked Dual-Asset B-Cell Pipeline of Anti-CD19 mAb and Differentiated Anti-APRIL "Sweeper" with Nephrology Emphasis; Initiate at Buy with $35 PT

assets and $249MM

CLYM BUY in pro forma cash after the April 2025 PIPE, the current ~$840MM market cap looks dislocated versus the upcoming catalyst calendar.

Climb Bio, Inc.

Sector: Biotechnology Investment Summary:

Budoprutug's anti-CD19 approach is clinically de-risked by AMGN's Uplizna's multi- Initiating Coverage • De-risked lead asset with validated mechanism:

Share Price $10.55 indication success. In the small Phase Ib (n=5) primary membranous nephropathy (PMN) study, budoprutug delivered 60% CR, 100%

Price Target $35.00 overall response with 3-year durability off immunosuppression and a clean safety profile — a profile that, if reproduced in the Phase II

PrisMN study (4Q26), could position budoprutug as best-in-disease in an indication with no FDA-approved therapy to date. In addition,

the SubQ formulation has shown ~80% B-cell depletion comparable to IV at ≥175 mg/mL, providing a convenience edge over IV-only

Market Data B-cell depleters (e.g., ROG-SWX's Gazyva and AMGN's Uplizna) in chronic settings. We like the PMN indication (Phase II data coming

52-Week Range $1.16 - $12.48 in 4Q26) for budo as there is limited competition. Success in SLE and or ITP could drive additional upside.

Shares Out (M) 79.8 CLYM116's pH-dependent "sweeper" mechanism • Differentiated second asset expands reach into the potential $10B IgAN market:

Market Cap (M) $842 eliminates rather than neutralizes APRIL, with NHP data showing 2–3x longer half-life vs. Otsuka's Voyxact, >70% maximal IgA

Enterprise Value (M) $593 reduction, and lower high molecular weight complex formation suggesting reduced immunogenicity risk.