BridgeBio Pharma Shares Positive Phase 2b Data and Announces Pivotal Study Design for Phase 3 Trial of Encaleret in Autosomal Dominant Hypocalcemia Type 1 (ADH1)

- Treatment with encaleret resulted in rapid and sustained restoration of normal mineral homeostasis, with mean values of blood calcium, urinary calcium, and blood PTH within the normal range by day 5 of therapy and sustained at 24 weeks, and was well-tolerated without any reported serious adverse events

- At week 24 of encaleret treatment, 92% (12/13) of participants had achieved normal trough blood calcium levels in the absence of extra-dietary calcium supplements and active vitamin D, and 77% (10/13) of participants had normal urinary calcium excretion

- The Company completed its end of Phase 2 interaction with the US FDA; the Phase 3 pivotal study is anticipated to begin in 2022 and will evaluate a primary composite endpoint of blood and urinary calcium within target ranges in participants treated with encaleret compared to standard of care

- Phase 2b data are featured in an oral presentation at the Endocrine Society (ENDO) 2022 Annual Conference

- BridgeBio will host an investor call on June 13, 2022, at 4:30 pm ET to discuss the Phase 2b study results and the planned pivotal Phase 3 study design

PALO ALTO, Calif., June 13, 2022 (GLOBE NEWSWIRE) -- BridgeBio Pharma, Inc. (Nasdaq: BBIO) (“BridgeBio” or the “Company”), a commercial-stage biopharmaceutical company focused on genetic diseases and cancers, today announced positive Phase 2b data of encaleret in patients with autosomal dominant hypocalcemia type 1 (ADH1). The results are featured in an oral presentation at the Endocrine Society (ENDO) 2022 Annual Conference in Atlanta, GA. BridgeBio will also host an investor call on June 13, 2022, at 4:30 pm ET to discuss the results from the Phase 2b study.

“ADH1 is a rare genetic form of hypoparathyroidism associated with lifelong abnormally high urine calcium and low blood calcium levels, sometimes leading to severe consequences such as seizures, heart rhythm abnormalities, muscle cramping, and breathing difficulties,” said Rachel Gafni, M.D., senior research physician and head of the Mineral Homeostasis Studies Group of the National Institute of Dental and Craniofacial Research of the National Institutes of Health (NIH). “Current management with calcium and vitamin D supplements is inadequate and may exacerbate high urine calcium levels, which can cause kidney complications. These 24-week outpatient data, evaluating an investigational calcilytic in a precision-medicine approach, demonstrate that encaleret has the potential to restore normal calcium and phosphate metabolism in individuals with ADH1.”

Thirteen adults with ADH1 caused by nine unique CASR variants participated in the three-period, Phase 2b, open-label, dose-ranging study. Oral calcium and activated vitamin D supplements were discontinued prior to encaleret initiation. Periods 1 and 2 each evaluated encaleret over the course of five inpatient days and Period 3 included a 24-week outpatient evaluation. Key results from the Phase 2b study include:

• Encaleret was well tolerated with no serious adverse events reported; there were no treatment discontinuations or study withdrawals
• Key biochemical parameters of mineral homeostasis, summarized in the table below, were normalized by Period 2, Day 5 and were sustained through Period 3, Week 24 of the trial