KEY POINTS
- BridgeBio Pharma reported positive late-stage trial results for its oral drug infigratinib, showing improved growth in children with achondroplasia.
- The Phase 3 PROPEL 3 study met its main and secondary endpoints, with statistically significant gains in height and body proportionality.
- BridgeBio plans regulatory filings in the U.S. and Europe in the second half of 2026.
Biotechnology company BridgeBio Pharma announced that its experimental oral medicine infigratinib demonstrated encouraging results in a pivotal Phase 3 trial designed to treat achondroplasia, the most common genetic cause of dwarfism in children. The study, known as PROPEL 3, showed statistically significant improvements in both annualized height velocity and measures of body proportionality compared with placebo over a 52-week treatment period.
Achondroplasia results from an overactive FGFR3 protein that inhibits normal bone growth, leading to disproportionate short stature and other health challenges in affected children. In the PROPEL 3 study, children receiving infigratinib experienced faster growth than those getting placebo, with mean treatment differences of around +1.74 cm per year and higher gains on some measures, surpassing placebo outcomes by a meaningful margin.
The trial also met a key secondary goal by demonstrating the first statistically significant improvement in body proportionality — a relevant clinical measure — in younger children under eight years old compared with placebo. Improvements in height Z-scores further supported the overall efficacy of infigratinib in addressing the skeletal growth limitations seen in achondroplasia.
Infigratinib was generally well tolerated during the study, with no serious adverse events attributed to the therapy and only a small percentage of mild, transient side effects. Importantly, children remained on the drug throughout the trial without treatment-related discontinuations, bolstering confidence in its safety profile for this patient population.
BridgeBio’s announcement marks a potential shift in achondroplasia treatment because infigratinib is an oral therapy, offering a more convenient alternative to existing injectable medications currently approved for the condition. The only approved drug at present, an injectable therapy known as vosoritide, has shown positive effects on growth but requires daily administration via injection.
BridgeBio said it intends to meet with regulatory authorities to discuss plans for submitting a New Drug Application (NDA) in the United States and a Marketing Authorization Application (MAA) in Europe in the latter half of 2026. If successfully approved, infigratinib would become the first oral treatment option for achondroplasia, expanding therapeutic choices for families and clinicians managing the condition.
Beyond its impact on height, the improvements in body proportionality may translate into better overall physical function for children with achondroplasia. While achondroplasia primarily affects linear growth, disproportionate limb-to-torso ratios can also influence mobility and joint health. Results from the PROPEL 3 study suggest that infigratinib could address these broader aspects of the condition, though further research will be essential to confirm long-term clinical benefits.
Analysts in the biotech sector have highlighted that an effective oral therapy could significantly alter the commercial landscape for achondroplasia treatments. Accessibility and ease of administration may make infigratinib a preferred option over injectable competitors, particularly for young children and their caregivers. Market observers noted that positive Phase 3 data often attract accelerated regulatory interest, particularly for rare diseases with high unmet needs.
BridgeBio is also exploring infigratinib’s potential in another genetic growth disorder, hypochondroplasia, a milder form of dwarfism. Encouraging results in achondroplasia could pave the way for broader development programs in related skeletal dysplasia conditions, addressing a spectrum of unmet therapeutic needs among affected families.
The PROPEL 3 findings represent a major milestone in the development of precision medicines targeting the underlying genetic mechanisms of rare growth disorders. For families living with achondroplasia, the possibility of an effective, daily oral treatment could offer not only convenience but also hopeful progress toward improved outcomes in stature and overall quality of life.
