Oral achondroplasia drug candidate infigratinib receives FDA priority review, with decision expected next February

For children with achondroplasia and their families, treatment means more than growing taller; it also involves body proportions, daily functioning, and how medication is taken. The oral drug candidate infigratinib has now reached the regulatory review stage: BridgeBio announced on October 6 that the U.S. Food and Drug Administration (FDA) had accepted its new drug application and granted priority review, with a target decision date of February 4, 2027.

This development brings an oral treatment option closer to clinical use, but neither acceptance of the application nor priority review constitutes approval, and the target date is not a promise of approval. BridgeBio said it was prepared to launch the drug in the United States upon approval; a same-day report from RTTNews also confirmed that the company plans to submit a marketing authorization application to the European Medicines Agency in the fourth quarter of 2026.

Achondroplasia is associated with activating variants in the FGFR3 gene. Overactive signaling by this receptor disrupts normal growth plate development, resulting in short stature with disproportionate limbs and trunk, and may also be accompanied by sleep apnea, middle ear problems, and spinal complications. Infigratinib is a small-molecule drug that aims to reduce this pathway’s constraints on bone growth by inhibiting FGFR3 signaling.

The core evidence supporting the application comes from the global Phase 3 PROPEL 3 trial. According to results released by the company, the change from baseline in annualized height velocity at week 52 met the primary endpoint: the least-squares mean difference versus placebo was an increase of 1.74 centimeters per year, while a separately reported mean difference was an increase of 2.10 centimeters per year. These are between-group differences calculated using different statistical estimation methods, and do not mean that every child will gain the same additional height. The key secondary endpoint of change in height Z-score also reached statistical significance.

The body proportion results add another dimension to the growth data. The company said that a prespecified exploratory analysis of children younger than 8 years showed a statistically significant improvement in body proportions with infigratinib compared with placebo. However, this finding comes from an exploratory analysis of an age subgroup and must be interpreted separately from the primary endpoint. It also does not allow a direct inference that children of all ages will experience the same effect, or that improved daily functioning has been demonstrated.

On safety, BridgeBio said there were no serious adverse events related to the study drug in the trial, and no treatment discontinuations due to adverse events related to the study drug. This provides supportive data over 52 weeks of treatment, but does not mean there were no side effects, nor is it sufficient to answer questions about the safety of years of treatment in children or whether improved growth velocity can translate into greater adult height or fewer complications.

The upcoming FDA review will determine whether these data can support approval, as well as the eligible population and conditions of use. For families, an oral formulation could expand their options; what still needs to be clarified is which sustained health benefits this option can deliver, and over what period.