Climb Bio to show Phase 2 budoprutug and CLYM116 data at ASN 2026
Climb Bio has confirmed four presentations at the American Society of Nephrology Kidney Week 2026, taking place in Denver, Colorado from 21 to 25 October. The disclosures cover its two lead programmes: budoprutug, an anti-CD19 monoclonal antibody, and CLYM116, an anti-APRIL antibody in development for IgA nephropathy.
The most closely watched slot is an oral presentation on 24 October, when the company will share preliminary Phase 2 data from PrisMN, its ongoing study of budoprutug in primary membranous nephropathy. Oral sessions at ASN are competitive and signal that the programme review committee considered the dataset sufficiently novel for a plenary-style audience, rather than a poster slot.
Budoprutug: breadth of the B-cell depletion story
Budoprutug is engineered with low fucosylation to enhance effector function and binds CD19 with low picomolar affinity. The design is intended to deplete a broad population of B cells, including plasmablasts and certain plasma cells that produce pathogenic autoantibodies. Alongside the PrisMN oral, Climb Bio will present a case study in minimal change disease, a distinct podocytopathy, suggesting the company is building evidence for budoprutug across multiple glomerular indications.
The FDA has granted budoprutug both Orphan Drug Designation and Fast Track Designation for primary membranous nephropathy, procedural milestones that reflect the unmet need in the indication but do not guarantee approval. Beyond pMN, the company is running trials in immune thrombocytopenia and systemic lupus erythematosus, and a subcutaneous formulation is in development, which would be relevant to long-term dosing in a chronic autoimmune setting.
CLYM116 and the APRIL-sweeper mechanism
CLYM116 contributes two poster presentations at ASN 2026, both reporting Phase 1 safety, tolerability, pharmacokinetics, and pharmacodynamics data from healthy volunteers. The antibody uses a pH-dependent bind-and-release mechanism the company describes as a "sweeper" design, intended to promote lysosomal degradation of APRIL and recycle the antibody to extend its half-life. The premise is that deeper APRIL suppression may translate into durable reductions in IgA immune complexes in the kidney, though clinical proof of concept in IgAN patients has not yet been reported.
IgA nephropathy is a rapidly evolving space. Sparsentan and atrasentan have received regulatory approval in recent years, and a number of APRIL- and BAFF-targeting biologics are in clinical development from both large pharma and well-capitalised biotechs. CLYM116's differentiated mechanism will need to demonstrate an efficacy or dosing advantage over existing and emerging APRIL-pathway inhibitors to carve out a durable commercial position.
Conference context and what to watch
ASN Kidney Week has become an increasingly important venue for immune-mediated renal disease data as the pipeline has thickened. Analysts and potential partners will scrutinise the PrisMN readout for proteinuria reduction kinetics and the durability of B-cell depletion, alongside any emergent safety signals. For CLYM116, the key question from the Phase 1 posters is whether PK and PD profiles support once-monthly or less frequent dosing, a claim the company has flagged as a design goal.
Abstracts for all four presentations are publicly available on the ASN 2026 website ahead of the conference. Climb Bio has not indicated when full datasets from either programme will be submitted for peer review or when it expects to advance CLYM116 into a patient cohort.