MBX Biosciences, Inc. today announced the successful completion of an End-of-Phase 2 (EOP2) meeting with the U.S. Food and Drug Administration (FDA) to discuss the overall Phase 3 trial design for once-weekly canvuparatide for the treatment of chronic hypoparathyroidism (HP).
“We are very encouraged by the outcome of our End-of-Phase 2 meeting and the constructive feedback supporting our planned Phase 3 trial for canvuparatide,” said Sam Azoulay, M.D., Chief Medical Officer of MBX Biosciences. “We believe canvuparatide has the potential to establish a new standard of care in hypoparathyroidism by restoring physiologic PTH activity and maintaining normocalcemia with the convenience of a patient-centric once-weekly dosing regimen. Feedback from physicians and patients has reinforced strong interest in a less burdensome treatment option, which we believe should translate into enthusiastic enrollment in the Phase 3 trial, and we look forward to enrolling the first patient in Q3 2026 now that we have confirmed the regulatory path toward an NDA submission.”
Based on feedback from the FDA, MBX plans to advance once-weekly canvuparatide into a Phase 3 trial in the third quarter of 2026. Phase 3 trial design elements have now been selected, including the number of patients, primary endpoint (including proportion of participants who achieve normal serum calcium and independence from conventional therapy) and key secondary endpoints (including normalization of urinary calcium), as well as dose selection, titration schedule and duration of the study.
The Phase 3 double-blind placebo-controlled trial will enroll approximately 160 patients, randomized in a 3:1 ratio to receive canvuparatide or placebo. Following randomization, there will be a 4-week fixed dose period of 600 micrograms of canvuparatide (or placebo), followed by an 18-week dose-titration period, and a 4-week maintenance period. The primary efficacy analysis will be assessed at Week 26, followed by a transition to an open label extension to assess both long-term safety and durability of effect.
The Company also announced today that once-weekly canvuparatide has been granted orphan drug designation by the European Medicines Agency for the treatment of chronic hypoparathyroidism, supporting its continued clinical development in Europe.
About Canvuparatide
Canvuparatide is a parathyroid hormone peptide prodrug that is designed as a potential long-acting hormone replacement therapy for the treatment of HP. Leveraging the company’s proprietary Precision Endocrine Peptide™ (PEP™) platform technology, canvuparatide was designed to provide convenient, once-weekly administration and a continuous, infusion-like PTH exposure with lower daily peak-to-trough ratios than observed with daily PTH dosing regimens. Canvuparatide received orphan drug designation from the U.S. Food and Drug Administration for the treatment of HP.
About Hypoparathyroidism (HP)
HP is a rare endocrine disease caused by a deficiency of parathyroid hormone (PTH) released by the parathyroid glands that results in decreased calcium levels in the blood, leading to hypocalcemia. Hypocalcemia can cause a variety of symptoms, such as muscle cramping or spasm, tingling, and neurological symptoms such as depression, confusion, and cognitive impairment. More serious complications can occur, including seizures and cardiac arrhythmia. HP can interfere with daily activities, negatively impacting the quality of life for patients. We estimate that HP affects more than 250,000 individuals in the U.S. and Europe. The current standard of care for HP does not address the underlying cause of the disease, PTH deficiency, and consists primarily of high doses of oral calcium and active vitamin D supplements.