MBX Biosciences says canvuparatide achieved primary endpoint in Phase 2 trial

MBX Biosciences (MBX) announced once-weekly canvuparatide achieved the primary endpoint with statistical significance at Week 12 in its Phase 2 Avail trial, and demonstrated positive 6-month results from the OLE, in adult patients with chronic hypoparathyroidism. All patients completed the 12-week study, and 94% of patients elected to enroll in the OLE. In the 12-week randomized portion of the trial, 63% of canvuparatide-treated patients met the prespecified primary composite endpoint with zero contribution from PRN rescue therapy. In the OLE, 79% of patients receiving once-weekly canvuparatide achieved responder status at 6 months. Responders were defined as patients who maintained serum calcium levels in the normal range and independence from conventional therapy. Based on these positive results, MBX is preparing to initiate a Phase 3 clinical trial of once-weekly canvuparatide in 2026. Phase 2 Avail Topline Results: 12-week and 6-month Responder Rates: At 12 Weeks: The primary composite endpoint and independence from conventional therapy was achieved in 63% of canvuparatide-treated patients compared with 31% in placebo-treated patients at Week 12. At 6 Months: In the OLE, 79% of patients who received treatment achieved responder status at 6 months, including patients initially randomized to placebo. Select Secondary and Exploratory Endpoints: Pharmacokinetics: Pharmacokinetic findings were consistent with the Phase 1 results, supporting a once-weekly dosing schedule. Bone Activity: Bone turnover and formation markers increased over 12 weeks compared to placebo, consistent with enhanced bone remodeling. Kidney Activity: In patients with elevated urine calcium at screening that normalized at Week 12, mean urine calcium was reduced by 48% in patients treated with once-weekly canvuparatide compared with 33% on placebo. Safety Summary: All doses of canvuparatide were generally well-tolerated with no discontinuations related to canvuparatide. Most treatment emergent adverse events were categorized as mild or moderate. No SAEs related to canvuparatide were reported. Injection site reactions: 19% in the pooled treatment group versus 13% in placebo. No deaths were reported.