The U.S. Food and Drug Administration has accepted BridgeBio’s new drug application for BBP-418, granting it priority review for the treatment of limb-girdle muscular dystrophy type 2I/R9 (LGMD2I/R9), according to a May 27 announcement from the company. The FDA set a target action date of November 27 and does not plan to hold an advisory committee meeting regarding the application.
BridgeBio said that BBP-418 could become the first approved therapy for this rare form of muscular dystrophy. The company is supporting its application with data from the Phase 3 FORTIFY trial, where the oral therapy met all primary and secondary endpoints at a pre-specified 12-month interim analysis. According to BridgeBio, treated individuals showed improvement while those receiving placebo declined across key measures, including increases in ambulatory and pulmonary function as well as a 5% increase in predicted pulmonary volume versus placebo.
William Blair analysts called this development “incremental positives for an approval and launch of the product in late 2026 or early 2027,” estimating worldwide sales of $1.1 billion in 2035 for BBP-418 based on current data. Jefferies analysts said they have “90%+ confidence” in full approval based on FORTIFY interim results, adding that peak sales could exceed $1 billion globally with more than $600 million projected in U.S. sales.
LGMD2I/R9 is caused by mutations in the FKRP protein that reduce but do not eliminate its function, leading to progressive skeletal muscle damage affecting lower and upper limbs before involving pulmonary and cardiac muscles later in disease progression. "Patients ultimately die from respiratory failure," BridgeBio Neuromuscular CEO Christine Siu said Wednesday.
BridgeBio’s progress comes amid increased activity across several forms of muscular dystrophy therapies approaching regulatory milestones. Duchenne muscular dystrophy has seen recent positive developments; Dyne Therapeutics submitted a Biologics License Application earlier this week for DYNE-251 targeting exon 51 skipping, while other companies such as REGENXBIO, Wave Life Sciences, Capricor Therapeutics, Novartis, Solid Biosciences, and Sarepta are nearing FDA submissions or regulatory finish lines with their own candidates.
