BridgeBio Scores Another Win with Rare Disease Drug Encaleret

BridgeBio Pharma has announced positive results from a late-stage clinical trial for encaleret, its experimental treatment for autosomal dominant hypocalcemia Type 1 (ADH1), marking another significant advancement in the company's rare disease research portfolio.

Encaleret Shows Promise in ADH1 Treatment

The Phase 3 study of encaleret met all primary and key secondary endpoints in patients with ADH1, a rare inherited endocrine disorder. After 24 weeks of treatment, 76% of participants receiving encaleret achieved normalized calcium levels in both blood and urine, compared to only 4% in the control group receiving conventional therapy.

Additionally, a secondary analysis revealed that encaleret corrected parathyroid hormone levels in 91% of treated patients, with all responders able to discontinue calcium and vitamin D supplements. Dr. Michael Mannstadt, Chief of the Endocrine Unit at Massachusetts General Hospital and a study investigator, stated that encaleret has the potential "to become an important new standard of care for this patient community."

BridgeBio's Strategic Advancements

This success comes on the heels of another recent late-stage trial victory for BridgeBio. Earlier this week, the company reported positive results for BB-418, a treatment for a form of muscular dystrophy. Both encaleret and BB-418 are projected by Wall Street analysts to potentially yield market opportunities exceeding $1 billion each.

The company's recent achievements have led to a significant boost in investor confidence. BridgeBio's share price has more than doubled since January 2025, partly due to the early commercial success of Attruby, its treatment for a genetic heart condition.

Market Impact and Future Prospects

BridgeBio estimates that approximately 12,000 patients in the U.S. have ADH1, with 3,000 to 5,000 suffering from uncontrolled or severe disease. The company plans to file for regulatory approval of encaleret next year, potentially offering a new treatment option for this underserved patient population.

Analyst reactions to the trial results have been positive. TD Cowen analyst Tyler Van Buren described the statistically significant benefit over typical care as "paradigm shifting," while Mizuho Securities analyst Salim Syed noted that the results "achieved (and sometimes exceeded) Street and company expectations."

As BridgeBio continues to demonstrate success in its rare disease pipeline, the pharmaceutical industry will be watching closely to see how these developments shape the landscape of treatments for genetic and rare disorders.