BridgeBio Pharma, Inc. (Nasdaq: BBIO), a biopharmaceutical company focused on genetic diseases, has announced positive 18-month results from the Phase 2 PROPEL 2 trial evaluating infigratinib as a treatment for children with achondroplasia. The findings, published today in the New England Journal of Medicine (NEJM) and presented at the 62nd Annual European Society for Paediatric Endocrinology (ESPE) Meeting in Liverpool, highlight the investigational therapy’s efficacy and safety profile.
Infigratinib, an oral small molecule inhibitor targeting FGFR3 signaling, is designed to address the underlying cause of achondroplasia, the most common form of disproportionate short stature. The data suggest it has the potential to improve growth and overall functionality in children with this condition.
Key Findings
Dr. Ravi Savarirayan, M.D., Ph.D., of Murdoch Children’s Research Institute and lead investigator for PROPEL 2, emphasized the significance of the findings:
“These results demonstrate the potential of infigratinib to not only increase height but also improve functionality and quality of life for children with achondroplasia.”
Key data shared during the ESPE meeting include:
- Improved Growth Rates:
- Children in Cohort 5 (0.25 mg/kg/day dose) showed a statistically significant increase in annualized height velocity (AHV), with a mean change from baseline of +2.50 cm/year (p=0.001) at Month 18.
- Height Z-scores increased by a mean of +0.54 (p<0.001) compared to untreated populations.
- Enhanced Body Proportionality:
- Improvement in body proportionality was observed, with a reduction in the upper-to-lower body segment ratio by -0.12 (p=0.001).
- Safety and Tolerability:
- Infigratinib was well tolerated, with no serious adverse events (SAEs) or treatment-emergent adverse events (TEAEs) leading to treatment discontinuation.
- No adverse changes in bone age, bone mineral density, or other bone-related side effects were observed.
Expert Commentary
Dr. Melita Irving, a clinical geneticist and investigator for the study, commented on the safety findings:
“The absence of adverse safety signals is particularly encouraging. We look forward to further evaluating infigratinib in the ongoing Phase 3 PROPEL 3 trial and the ACCEL program for children with hypochondroplasia.”
Regulatory Designations and Next Steps
Infigratinib has received multiple regulatory designations from the U.S. Food and Drug Administration (FDA), including:
- Breakthrough Therapy Designation for its potential to demonstrate substantial improvement over existing therapies.
- Orphan Drug Designation, Fast Track Designation, and Rare Pediatric Disease Designation for achondroplasia.
If approved, BridgeBio may qualify for a Priority Review Voucher, further accelerating the path to making infigratinib available to patients.
Ongoing Research
BridgeBio is continuing its evaluation of infigratinib in PROPEL 3, a Phase 3 trial currently enrolling participants, as well as the Phase 2 ACCEL program targeting hypochondroplasia. These efforts aim to expand understanding of the drug’s impact on growth, functionality, and broader medical needs in skeletal dysplasias.
Commitment to Advancing Treatments
BridgeBio remains dedicated to addressing significant unmet needs in genetic diseases, with infigratinib emerging as a potential first-in-class oral therapy for achondroplasia and other skeletal dysplasias.
