PALO ALTO, Calif. — October 11, 2026
BridgeBio Pharma, Inc. presented new bone turnover and patient-reported outcome findings from its Phase 3 CALIBRATE trial evaluating investigational encaleret in patients with autosomal dominant hypocalcemia type 1 (ADH1). Presented at the American Society for Bone and Mineral Research (ASBMR) 2026 Annual Meeting in Boston, the results showed increased bone turnover markers and improvements in reported symptoms and daily functioning compared with standard of care. Encaleret stimulated endogenous parathyroid hormone (PTH) secretion to at or above the lower limit of normal in 91% of participants, compared with 0% receiving conventional treatment. Additionally, 100% of encaleret-treated participants reported improvement in at least one ADH1-related symptom at 24 weeks, compared with 46% receiving standard of care. BridgeBio also announced that the first participant had been dosed in RECLAIM-HP, a registrational Phase 3 trial evaluating encaleret in adults and adolescents with chronic hypoparathyroidism. The company’s New Drug Application (NDA) for encaleret in ADH1 has been accepted by the U.S. Food and Drug Administration (FDA) under Priority Review, with a target action date of May 8, 2027. Encaleret remains investigational for these conditions.
Encaleret Increases Bone Turnover in CALIBRATE Trial
The 24-week CALIBRATE findings indicate that encaleret may help restore aspects of normal bone physiology in ADH1 by stimulating the body’s own PTH secretion. ADH1 is a genetic disorder caused by gain-of-function variants in the calcium-sensing receptor gene (CASR), resulting in abnormally low PTH secretion, low blood calcium and frequently increased urinary calcium excretion. Insufficient PTH can also contribute to reduced bone turnover. In the Phase 3 trial, 91% of participants receiving encaleret achieved endogenous PTH secretion at or above the lower limit of normal, compared with none receiving standard of care. Investigators also observed increases in markers of bone formation and resorption in the encaleret group relative to conventional therapy. These changes are consistent with the biological effects expected when PTH secretion is restored. The findings were presented by Erik Imel, M.D., of Indiana University School of Medicine at the ASBMR annual meeting. Although the biomarker changes suggest that encaleret may address disease mechanisms beyond blood calcium correction, further evaluation is needed to determine their long-term clinical significance and whether they translate into improved skeletal outcomes.
Patient-Reported Symptoms and Daily Functioning Improve
A separate CALIBRATE presentation highlighted improvements in ADH1-related symptoms and daily functioning among participants treated with encaleret compared with those receiving standard care, which included calcium supplementation and/or active vitamin D. At Week 24, all participants in the encaleret group reported improvement in at least one symptom, compared with 46% in the standard-of-care group. Reported improvements were more frequent with encaleret for fatigue (61.3% versus 27.3%), muscle cramps (58.1% versus 36.4%), muscle spasms (58.1% versus 18.2%), tingling (51.6% versus 9.1%) and brain fog (48.4% versus 9.1%). Participants also reported improvements in daily functioning, including mood and emotions (61.3% versus 27.3%), physical activities (45.2% versus 9.1%), daily life (35.5% versus 18.2%) and work life (35.5% versus 9.1%). The findings were presented by Steven Ing, M.D., of Ohio State University, a CALIBRATE investigator. These patient-reported outcomes are important because ADH1 symptoms can affect everyday activities and quality of life. However, the reported comparisons should be interpreted in the context of the trial design and the full clinical dataset.
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BridgeBio Advances Encaleret Regulatory and Clinical Programs
BridgeBio reported additional progress across its encaleret development program. The FDA has accepted the company’s NDA for encaleret in ADH1 and granted Priority Review, with a Prescription Drug User Fee Act (PDUFA) target action date of May 8, 2027. BridgeBio has also submitted a Marketing Authorisation Application to the European Medicines Agency. Separately, the company has initiated RECLAIM-HP, a global, randomized, double-blind, placebo-controlled Phase 3 study of oral encaleret in adults and adolescents with chronic hypoparathyroidism. The trial plans to enroll approximately 160 participants, randomized in a 3:1 ratio to encaleret or placebo during a 24-week double-blind treatment period. Its primary endpoint is the proportion of participants achieving target ranges for both blood and urine calcium at Week 24. Secondary endpoints include reduced dependence on conventional therapy, patient-reported outcomes, bone mineral metabolism and long-term safety. BridgeBio and the HypoPARAthyroidism Association also presented findings from a regional family genetic testing initiative, in which 44% of 27 participants were symptomatic at testing and 77% of those symptomatic participants had experienced symptoms for more than two years. Together, these developments support continued investigation of encaleret in rare calcium-regulation disorders, while regulatory decisions and further clinical evidence will determine its eventual role in treatment.
Source::BridgeBio press release
