PALO ALTO, Calif., June 28, 2026
BridgeBio Pharma announced that positive results from its pivotal Phase 3 PROPEL 3 trial evaluating oral infigratinib in children with achondroplasia have been published in the New England Journal of Medicine (NEJM) and simultaneously presented as a late-breaking oral presentation at the International Congress of Children’s Bone Health (ICCBH) 2026. The study represents the first Phase 3 achondroplasia clinical trial published in NEJM and demonstrated statistically significant improvements in annualized height velocity (AHV), body proportionality, and arm span compared with placebo. The company stated that oral infigratinib was well tolerated, with no serious treatment-related adverse events or treatment discontinuations, reinforcing its potential as a first-in-class oral therapy targeting the underlying cause of achondroplasia.
Phase 3 PROPEL 3 Meets Primary and Key Secondary Endpoints
The PROPEL 3 study successfully achieved its primary endpoint, showing a least squares mean treatment difference of +1.74 cm/year in annualized height velocity versus placebo (p<0.0001), while the observed mean improvement reached +2.10 cm/year, the largest improvement reported in any Phase 3 achondroplasia trial. The trial also met its key secondary endpoint, demonstrating a statistically significant improvement in height Z-score at Week 52 (p<0.0001). Additionally, oral infigratinib became the first therapy to demonstrate statistically significant improvement in body proportionality in a placebo-controlled Phase 3 achondroplasia study among children aged 3 to 8 years, while newly presented ICCBH data revealed the first statistically significant placebo-controlled improvement in arm span with a +0.37 SD increase (p<0.0001). Safety findings remained favorable, with only three mild, transient cases of hyperphosphatemia and no retinal, corneal, or FGFR1/FGFR2-related adverse effects observed.
Additional Clinical Findings Support Broader Benefits
BridgeBio also presented additional analyses highlighting the broader impact of achondroplasia on patients and families. Data from the global observational PROPEL study demonstrated that children with achondroplasia experience significantly reduced health-related quality of life, particularly in physical functioning and everyday activities. Separate qualitative research involving children with hypochondroplasia and their caregivers confirmed that commonly used patient-reported outcome measures accurately reflect the real-world physical, emotional, and quality-of-life challenges associated with the condition. These findings strengthen the scientific rationale for incorporating patient-centered outcomes into future clinical development programs evaluating oral infigratinib.
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Regulatory Plans and Future Development
Building on these positive Phase 3 findings, BridgeBio plans to submit a New Drug Application (NDA) to the U.S. FDA during the third quarter of 2026, followed by a Marketing Authorization Application (MAA) to the European Medicines Agency (EMA) in the second half of 2026, with a potential U.S. commercial launch anticipated in early to mid-2027. Oral infigratinib has already received Breakthrough Therapy, Fast Track, Orphan Drug, and Rare Pediatric Disease Designations from the FDA, highlighting its importance for addressing a significant unmet medical need. The company is also advancing additional clinical programs, including PROPEL Infant & Toddler and ACCEL 2/3 studies, to evaluate the therapy across a broader range of skeletal dysplasia conditions, aiming to provide the first approved oral, disease-targeted treatment for children living with achondroplasia and hypochondroplasia.
Source: BridgeBio Pharma press release
