FDA Grants Priority Review to BridgeBio’s Infigratinib

Rare Daily Staff

The U.S. Food and Drug Administration has accepted BridgeBio Pharma’s application for oral infigratinib to treat children with achondroplasia, a rare genetic disorder of bone growth, and granted it priority review, setting a target decision date of February 4, 2027.

If approved, infigratinib would become the first oral therapy for children with the genetic condition. The company said it is prepared to launch the medicine in the United States upon approval and plans to submit a European marketing application in the fourth quarter of 2026.

Achondroplasia is the most common cause of disproportionate short stature. It results from a genetic change that makes FGFR3 signaling overactive, disrupting bone growth. Beyond short stature, the condition can cause complications including obstructive sleep apnea, middle ear problems, spinal curvature and narrowing of the spinal canal.

Infigratinib is an experimental small molecule designed to reduce excessive FGFR3 signaling. BridgeBio is developing it for both achondroplasia and hypochondroplasia, another skeletal growth condition. Infigratinib previously received FDA breakthrough therapy designation based on results from BridgeBio’s PROPEL 2 trial, as well as orphan drug, fast track and rare pediatric disease designations.

The application follows results from PROPEL 3, a global, placebo-controlled phase 3 trial that met its primary goal of improving annualized height velocity after 52 weeks of treatment.

BridgeBio reported a statistically adjusted treatment difference of 1.74 centimeters per year over placebo and an unadjusted mean difference of 2.10 centimeters per year. The result was statistically significant. The study also met a key secondary endpoint measuring changes in height z-score, a standardized measure of height.

The company reported improvements in arm span and body proportionality as well. A prespecified exploratory analysis in children younger than 8, who accounted for more than half of participants, found a statistically significant improvement in body proportionality compared with placebo. BridgeBio reported an arm-span z-score improvement of 0.37 standard deviations over placebo.

Exploratory results also showed favorable trends in sleep apnea measures and middle ear infection events. These findings were separate from the trial’s primary and key secondary endpoints; the announcement did not report statistical significance for those outcomes.

Infigratinib was well tolerated in PROPEL 3, with no treatment discontinuations or serious adverse events related to the study drug.

“We also understand that for many families, it’s about more than just height or having an oral option,” said Justin To, CEO of BridgeBio Skeletal Dysplasias. He said the company would continue evaluating the drug’s effects on measures beyond growth.

Photo: CEO of BridgeBio Skeletal Dysplasias