BridgeBio's Infigratinib Achieves Primary Goals in Achondroplasia Phase 3 Trial

BridgeBio Pharma has unveiled encouraging efficacy results from its Phase 3 PROPEL 3 study of infigratinib in treating achondroplasia, the most prevalent genetic bone growth disorder affecting children. The one-year study enrolled pediatric patients aged 3 to less than 18 years with open growth plates and successfully achieved its primary efficacy objectives, representing a significant milestone for the company’s clinical pipeline and generating substantial investor interest with stock gains exceeding 14% in pre-market activity.

Efficacy Data Surpasses Historical Benchmarks

The trial demonstrated statistically significant improvements in annualized height velocity (AHV) at the 52-week timepoint compared to placebo control. Infigratinib-treated patients showed a mean absolute AHV of 5.96 cm per year—the highest value documented to date in any randomized achondroplasia trial—versus 4.22 cm per year for the placebo group. When calculated as treatment difference, patients receiving infigratinib gained +2.10 cm per year of additional height velocity, with a least squares mean difference of +1.74 cm per year relative to the control arm. This performance not only met but exceeded the primary endpoint threshold and secondary efficacy assessments.

Safety and Tolerability Profile

The oral formulation demonstrated a robust safety profile throughout the trial duration. Notably, no drug-related serious adverse events emerged, and zero patients discontinued due to treatment-related complications. This favorable tolerability supports the drug’s potential for long-term pediatric use in achondroplasia management, addressing a significant unmet medical need in this patient population.

Regulatory Path Forward

BridgeBio intends to advance infigratinib through the formal FDA approval process, with New Drug Application (NDA) and Marketing Authorization Application (MAA) submissions planned for the second half of 2026. Beyond achondroplasia, the company is accelerating development in hypochondroplasia, another related bone growth disorder, with enrollment underway for a Phase 3 observational run-in study. This expansion strategy positions BridgeBio to address multiple genetic skeletal dysplasias with a single mechanism-based therapeutic approach.