Key Takeaways:
The FDA accepted BridgeBio's NDA for encaleret in ADH1, setting a PDUFA target action date of May 8, 2027, the company said.
"The FDA's acceptance of our NDA is a powerful validation of encaleret's differentiated clinical profile and enables a major step forward for the ADH1 community," Ananth Sridhar, chief executive officer of BridgeBio Endocrinology, said.
The Phase 3 CALIBRATE trial achieved all pre-specified primary and key secondary efficacy endpoints, normalizing markers of calcium-sensing receptor-driven disease biology without requiring calcium and vitamin D supplements. The drug also showed a favorable safety and tolerability profile. Data presented at the European Congress of Endocrinology and the Endocrine Society's 2026 annual meeting showed simultaneous restoration of blood and urine calcium and physiologic parathyroid hormone production.
ADH1 is a genetic form of hypoparathyroidism caused by gain-of-function variants in the CASR gene, leading to hypocalcemia, hypercalciuria and inappropriately low PTH levels. Symptoms include severe muscle cramps, seizures, kidney stones and kidney failure. Over 2,100 individuals have been diagnosed in the US since October 2023, according to claims data. The FDA told BridgeBio it does not plan to hold an advisory committee meeting to discuss the application.
"For too long, ADH1 has been an invisible condition that disrupts several systems in the body, from the kidneys to the nervous system to the muscles and often goes unrecognized for years," Patty Keating, executive director of the HypoPARAthyroidism Association, said. "The FDA's acceptance of this NDA is a moment of real hope for ADH1 patients."
If approved, encaleret would be the first and only therapy specifically indicated for ADH1, representing a potential blockbuster opportunity for BridgeBio. The company is enrolling CALIBRATE-PEDS, a registrational Phase 2/3 trial in pediatric ADH1, and plans to start RECLAIM-HP, a Phase 3 study in chronic hypoparathyroidism, later this summer. BridgeBio also intends to submit a Marketing Authorization Application to the European Medicines Agency in the second half of 2026.
The NDA acceptance de-risks the regulatory pathway for encaleret. Investors will watch for a decision by the May 2027 PDUFA date, with potential expansion into chronic hypoparathyroidism representing a broader commercial opportunity.
This article is for informational purposes only and does not constitute investment advice.
