Phase III trial initiated for encaleret in autosomal dominant hypocalcemia type 1.- BridgeBio Pharma

The design of the CALIBRATE study incorporates feedback from global regulatory authorities and patients, with a primary composite endpoint of blood and urine calcium concentrations within normal ranges in participants treated with encaleret compared to standard of care (SoC). SoC for ADH1 consists of extra-dietary supplementation with calcium and/or active vitamin D analogs. While SoC may address acute symptoms related to hypocalcemia, it may exacerbate high urine calcium levels, which can cause renal complications. Secondary endpoints will evaluate other measures of mineral homeostasis, quality of life, and kidney function.

The CALIBRATE study advances the clinical development of encaleret following positive data from an ongoing Phase IIb trial in 13 participants with ADH1. In the Phase IIb study encaleret was generally well-tolerated, with no observed safety signals of potential clinical concern, and restored normal mineral homeostasis. Mean values of blood calcium, urinary calcium, and blood PTH came within the normal range by day 5 of encaleret treatment and were sustained for 24 weeks. At week 24 of outpatient treatment, 92% of participants receiving encaleret achieved normal blood calcium levels in the absence of SoC, and 77% of participants had achieved normal 24-hr urinary calcium excretion. Results of this study were presented at the Endocrine Society (ENDO) Annual Conference in June 2022. The long-term extension of the Phase IIb study is ongoing.