Climb Bio, Inc. and Beijing Mabworks Biotech Co., Ltd. announced additional Phase 1 data for CLYM116/MIL116, an anti-APRIL monoclonal antibody, at the American Society of Nephrology (ASN) Kidney Week 2026 in Denver, Colorado. The data were presented on October 23, 2026, and build upon initial results from randomized, double-blind, placebo-controlled ascending-dose studies conducted in healthy volunteers in Australia and China. These trials enrolled 46 and 42 participants, respectively, to evaluate the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of subcutaneous CLYM116.
The data indicate that CLYM116, engineered as a pH-dependent “sweeper” antibody, supports deep and durable suppression of APRIL with extended dosing intervals. Based on the 800 mg dose and the 320 mg multiple-ascending dose (MAD) cohort, the antibody demonstrated an estimated half-life of approximately 33 days. Pharmacokinetic data showed linear exposure across the studies, with no target-mediated drug disposition observed at doses of 160 mg or higher. This profile suggests the antibody works by recycling itself and degrading APRIL.
Regarding pharmacodynamics, a single subcutaneous injection of 480 mg or higher produced free APRIL suppression of 90% or more through the full 12-week dosing interval. A single 800 mg dose, which is the selected loading dose for the NAVIGATE-2 Phase 2 trial, resulted in reductions of approximately 70% in galactose-deficient IgA1 (Gd-IgA1) and approximately 60% in IgA at 12 weeks. The compound was generally well tolerated across all dose levels evaluated, with no serious adverse events, dose-limiting toxicities, or hypogammaglobulinemia reported. Injection site reactions occurred in 5 of the 88 participants across both studies, all of which were Grade 1 and resolved without intervention.
Climb Bio is currently enrolling patients with IgA nephropathy (IgAN) in the NAVIGATE-2 Phase 2 trial to confirm the every-12-week dosing regimen. The company expects to report initial data from this trial in the first half of 2027. Additionally, Climb Bio and Mabworks anticipate initiating a global Phase 3 trial in 2027, pending regulatory feedback.
