BridgeBio Pharma, Inc. (Nasdaq: BBIO) said the US FDA has accepted for filing its New Drug Application for encaleret, an investigational oral calcilytic, in individuals living with autosomal dominant hypocalcemia type 1 (ADH1). The agency assigned a Prescription Drug User Fee Act target action date of May 8, 2027, and said it does not currently plan to convene an advisory committee meeting. The Palo Alto, California-based company submitted the NDA in May 2026, and acceptance for filing confirms the FDA considers the application complete enough to undergo substantive review.
No therapy is currently approved specifically for ADH1, a rare condition caused by gain-of-function variants in the calcium-sensing receptor gene that suppress parathyroid hormone secretion and drive both hypocalcemia and hypercalciuria. Patients today are managed with calcium supplements and active vitamin D analogues, an approach that can worsen renal calcium excretion and elevate risk of nephrocalcinosis and kidney stones. Palopegteriparatide (Yorvipath), approved by the FDA in 2024, treats chronic hypoparathyroidism through PTH replacement but is not indicated for ADH1 and does not address the underlying CaSR defect.
Encaleret is designed as a negative allosteric modulator of the calcium-sensing receptor, reducing its sensitivity to calcium and thereby restoring more typical PTH secretion and renal calcium handling, rather than managing calcium levels downstream. The NDA is supported by the Phase III CALIBRATE trial, which BridgeBio said met all pre-specified primary and key secondary efficacy endpoints. In results presented at the European Congress of Endocrinology in May 2026, 76% of participants randomized to encaleret achieved both target serum and urine calcium levels at Week 24, compared with 19% of those remaining on standard therapy, and the drug was associated with restoration of endogenous PTH secretion in the majority of treated participants. The company reported a favorable safety profile, with no discontinuations in the encaleret arm.
BridgeBio has said it anticipates a US launch in early 2027 if the application is approved and plans to submit a Marketing Authorization Application to the European Medicines Agency in the second half of 2026. The company cited claims data indicating that more than 2,100 individuals in the US have been diagnosed with autosomal dominant hypocalcemia since a dedicated ICD-10 code was introduced in October 2023, a figure it described as evidence of a growing diagnosed population.