BridgeBio’s Infigratinib Yields +2.10 cm/Year Height Gain, Body Proportionality Win
BridgeBio’s Phase 3 PROPEL 3 trial of oral infigratinib met its primary endpoint with a 2.10 cm/year mean increase in annualized height velocity over placebo (p<0.0001) at Week 52. It also achieved significant body proportionality improvement (–0.05; p<0.05) with no serious adverse events, supporting H2 2026 NDA and MAA filings.
1. PROPEL 3 Trial Design
PROPEL 3 is a global, double-blinded, randomized (2:1) placebo-controlled Phase 3 study enrolling children aged 3 to <18 years with achondroplasia and open growth plates, evaluating oral infigratinib over 52 weeks for changes in growth velocity.
2. Primary and Secondary Efficacy Results
The trial met its primary endpoint with an LS mean increase of 1.74 cm/year in annualized height velocity over placebo (mean difference 2.10 cm/year; p<0.0001). Key secondary results included a +0.41 SD increase in height Z-score versus achondroplasia norms (p<0.0001).
3. Body Proportionality Improvement and Safety
Infigratinib achieved a statistically significant body proportionality improvement (LS mean –0.05; p<0.05) in children under 8 years. Treatment was well tolerated with no drug-related serious adverse events and only mild, transient hyperphosphatemia in 4% of participants.
4. Regulatory Path and Future Plans
NDA and MAA submissions for achondroplasia are planned for H2 2026, leveraging Breakthrough Therapy Designation. The program will expand into hypochondroplasia with a Phase 3 observational run-in currently enrolling.