Small-Cap Biotech Climb Bio's Lead Drug Candidate Has Larger Long-Term Opportunity

William Blair initiated coverage for Climb Bio (NASDAQ:CLYM), citing the potential of the company’s budoprutug, under development for autoimmune indications, including:

Phase 1b/2a immune thrombocytopenia (ITP) trial FPI achieved, enrollment ongoing.
Phase 1b systemic lupus erythematosus (SLE) trial FPI achieved, enrollment ongoing.
Phase 2 primary membranous nephropathy (pMN) trial will initiate in the coming weeks.

Continued development of subcutaneous (SC) formulation. Initial Phase 1 trial results for the budoprutug SC formulation are expected in the first half of 2026.

Also Read: Novartis Sees Hope In Reducing Lifelong Treatment Burden For Autoimmune Blood Disorder

The use of B-cell–depleting antibodies for autoimmune disease has been well validated with significant use of Roche Holdings AG (OTC:RHHBY) and Biogen Inc (NASDAQ:BIIB) partnered Rituxan (rituximab) and recent approvals, including Roche’s Ocrevus, Novartis AG’s (NYSE:NVS) Kesimpta, TG Therapeutics Inc.’s (NASDAQ:TGTX) Briumvi, as well as Amgen Inc.'s (NASDAQ:AMGN) Uplizna.

Analyst Matt Phipps says the market opportunity is sufficiently large to support additional players.

William Blair estimates combined peak sales for the ongoing three indications of $1.9 billion in 2040, and a risk-adjusted net present value (NPV) for Climb Bio of $812 million, or $11.78 per share, supporting an Outperform rating.

Analyst Phipps says, “We believe strong proof of concept has been achieved in at least 15 different autoimmune indications; therefore, we see a much larger long-term opportunity for budoprutug beyond the three indications being evaluated.”

William Blair says budoprutug has the potential to differentiate through subcutaneous administration and expansion into indications beyond those being pursued by Amgen.

The company also has CLYM116, an antibody targeting the APRIL pathway for IgA nephropathy (IgAN), advancing toward clinical development.

Climb Bio remains on track to submit an Investigational New Drug (IND) or Clinical Trial Application (CTA) for CLYM116 in IgAN in the second half of 2025.

Cash, cash equivalents, and marketable securities were $187.4 million as of June 30, 2025. Cash, cash equivalents, and marketable securities are expected to fund operations through 2027.

Price Action: Climb Bio’s stock was trading at around $1.99 per share, up 2.44%, at last check on Thursday.

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