MBX Biosciences Announces Full Results from Avail Phase 2 Trial

MBX Biosciences announced full results from the 12-week Avail Phase 2 trial and new one-year data from the ongoing open-label extension study of once-weekly canvuparatide in adult patients with chronic hypoparathyroidism. At 12 weeks: as previously reported, 63% of canvuparatide-treated patients achieved the primary composite endpoint compared with 31% of placebo-treated patients. The primary endpoint was defined as maintaining albumin-adjusted serum calcium levels in the normal range and independence from conventional therapy. At one year: 57% of evaluable patients achieved responder status; zero contribution from rescue therapy in the last week of the one-year treatment period. PK data from the Phase 2 trial continued to support the potential for once-weekly dosing. PK demonstrated consistent concentration of canvuparatide active drug with a Tmax of 2-3 days, minimal fluctuation and a peak-to-trough ratio of approximately 1.3 over a week, ensuring consistent systemic drug exposure over the entire weekly dosing interval. Mean serum calcium levels were maintained within the normal range through one year of treatment, while mean 24-hour urine calcium levels decreased from baseline and remained within the normal range, with continued reductions observed over time in both canvuparatide-treated patients and those who switched from placebo. Mean estimated glomerular filtration rate increased from baseline at Week 12 in canvuparatide-treated patients and remained improved through one year of treatment. Markers of bone resorption and formation demonstrated the expected pattern of bone turnover associated with PTH replacement therapy through one year. Changes in bone mineral density T-scores and Z-scores were consistent with restoration of physiologic bone remodeling. Once-weekly canvuparatide was generally well tolerated through one year of treatment, with no new safety signals observed during the OLE. Most treatment emergent adverse events were mild or moderate in severity. No treatment-related serious adverse events were reported. Injection site reactions were reported in 10% of patients in the OLE. Trends toward improvement were observed across multiple SF-36v2 domains; however, interpretation was limited by incomplete baseline data.