Climb Bio, Inc. announced positive initial data from its ongoing Phase 1 clinical trial evaluating CLYM116, an anti-APRIL monoclonal antibody, on September 3, 2026. The randomized, double-blind, placebo-controlled, single-ascending-dose (SAD) and multiple-ascending-dose (MAD) study enrolled 46 healthy volunteers to assess the safety, tolerability, pharmacokinetics, and pharmacodynamics of subcutaneous CLYM116.
The company reported that a single 320 mg dose of CLYM116 resulted in near-complete suppression of free APRIL, with greater than 90% suppression observed. This suppression was maintained through 12 weeks, supporting a potential dosing regimen of every 12 weeks. The data also indicated that IgA and galactose-deficient IgA1 (Gd-IgA1) levels were suppressed by approximately 60% to 75% following the single dose.
Regarding safety, the company stated that CLYM116 was generally well-tolerated with no serious adverse events or dose-limiting toxicities reported. The press release noted that the antibody has a projected half-life of approximately 29 days based on the 320 mg multiple-ascending-dose study, which is three times longer than sibeprenlimab.
Looking ahead, Climb Bio is advancing its Phase 2 NAVIGATE-2 trial in IgA nephropathy (IgAN). This study is randomized and open-label, evaluating an 800 mg loading dose of CLYM116 followed by maintenance doses of 400 mg every 8 weeks or every 12 weeks. The company anticipates initial data from NAVIGATE-2 in the first half of 2027 and plans to initiate a Phase 3 registrational study in 2027.
