PALO ALTO, Calif., July 22, 2026
BridgeBio has reached a significant regulatory milestone after the U.S. Food and Drug Administration (FDA) accepted its New Drug Application (NDA) for encaleret, an investigational oral therapy for Autosomal Dominant Hypocalcemia Type 1 (ADH1). The FDA has assigned a Prescription Drug User Fee Act (PDUFA) target action date of May 8, 2027, marking an important step toward what could become the first and only FDA-approved treatment specifically indicated for ADH1, a rare inherited endocrine disorder with no approved targeted therapies. The acceptance follows positive Phase 3 CALIBRATE clinical trial results, in which encaleret met all pre-specified primary and key secondary efficacy endpoints, restoring calcium balance and improving disease biomarkers while demonstrating a favorable safety and tolerability profile. The FDA also indicated that it is not currently planning to convene an advisory committee meeting, potentially streamlining the regulatory review process.
Phase 3 Results Support First Disease-Modifying Therapy
The NDA submission is supported by data from the pivotal CALIBRATE Phase 3 trial, where encaleret consistently normalized blood calcium levels, reduced urinary calcium excretion, restored physiologic parathyroid hormone (PTH) production, and eliminated the need for conventional calcium and vitamin D supplementation in many patients. Unlike current symptom-based management approaches, encaleret directly targets the calcium-sensing receptor (CaSR) responsible for the underlying genetic cause of ADH1, positioning it as a potential disease-modifying therapy. Patients with ADH1 often experience chronic hypocalcemia, muscle spasms, seizures, kidney complications, and neurological symptoms due to gain-of-function mutations in the CASR gene. BridgeBio believes the therapy could transform treatment by addressing disease biology rather than simply replacing calcium.
BridgeBio Expands Encaleret Development Beyond ADH1
Beyond the current NDA review, BridgeBio is continuing to expand the clinical development program for encaleret. The company is actively enrolling patients in the CALIBRATE-PEDS Phase 2/3 registrational trial evaluating the therapy in pediatric ADH1 patients while also preparing to initiate the RECLAIM-HP Phase 3 trial in chronic hypoparathyroidism. In parallel, BridgeBio plans to submit a Marketing Authorization Application (MAA) to the European Medicines Agency (EMA) during the second half of 2026. The company believes successful expansion into broader hypoparathyroidism indications could significantly increase the therapeutic impact of encaleret and address additional unmet medical needs in endocrine disorders. The therapy has already received FDA Fast Track Designation and Orphan Drug Designation in the United States, European Union, and Japan, further underscoring its potential importance for patients living with rare genetic diseases.
Advertisement
Regulatory Milestone Strengthens Rare Disease Portfolio
The FDA’s acceptance of the NDA represents another important milestone in BridgeBio Pharma’s rare disease strategy, reinforcing its commitment to developing precision medicines for genetically defined disorders. If approved, encaleret would become the first targeted therapy for ADH1, offering patients a treatment designed to correct the underlying disease mechanism instead of managing symptoms alone. With more than 2,100 diagnosed ADH1 patients identified in the United States since late 2023 and increasing awareness of the disorder among clinicians, BridgeBio expects continued growth in diagnosis and treatment opportunities. The upcoming FDA review, supported by robust Phase 3 efficacy data, orphan drug incentives, and Fast Track designation, positions encaleret as one of the most promising rare endocrine therapies currently under regulatory review and highlights continued innovation in precision medicine for underserved patient populations.
Source: BridgeBio Press release
