Shares of Climb Bio Inc (NASDAQ:CLYM) fell 2.7% in premarket trading on Friday after the company disclosed early safety and translational pharmacometric findings for its investigational antibody CLYM116.
The data were presented at the European Renal Association (ERA) Congress, held June 3-6, 2026, in Glasgow, Scotland. CLYM116 is an anti-APRIL monoclonal antibody under development for IgA nephropathy (IgAN). Climb Bio released translational modeling results alongside initial Phase 1 safety information.
Safety outcomes and tolerability
According to Climb Bio, single ascending doses of CLYM116 up to 320 mg were generally well tolerated in healthy volunteers. The preliminary safety dataset covered 49 participants who received either CLYM116 or placebo. Across that cohort, the company reported no serious adverse events, no dose-limiting toxicities, and no discontinuations related to adverse events.
All adverse events that occurred were described as mild to moderate in severity, transient, and self-resolving. The only specifically noted events were two injection site reactions, both graded as Grade 1, which resolved without intervention.
Study design and next steps
The observations come from two parallel Phase 1 programs - one run by Climb Bio in Australia and a second conducted by partner Beijing Mabworks Biotech in China. Based on the interim safety readouts, Mabworks has indicated an expectation to begin dosing IgAN patients in the Phase 2 portion of its study in the third quarter of 2026.
Climb Bio said it plans to present initial pharmacokinetic and pharmacodynamic data, together with updated safety results from the ongoing Phase 1 studies, at its R&D Spotlight Series event anticipated in late summer. The company retains worldwide rights to CLYM116 outside of Greater China.
Translational modeling
The translational pharmacometric model, which the company derived from non-human primate data, projected dose-dependent suppression of IgA with CLYM116. Climb Bio noted this projection could indicate the potential for less-frequent dosing relative to first-generation anti-APRIL approaches, as suggested by the modeling.
Context for investors
The market reaction - a modest premarket decline - followed the presentation of these early-stage findings. The clinical dataset presented is preliminary and limited to single-dose healthy volunteer data and translational projections; Climb Bio intends to provide further PK/PD and safety updates later in the summer as the Phase 1 programs progress.
Disclosure