Daniela Rogoff, MD, PhD, Chief Medical Officer, Skeletal Dysplasia of BridgeBio, discusses the efficacy of infigratinib to treat persons with achondroplasia.
Achondroplasia is a disorder of bone growth that prevents the changing of cartilage to bone, particularly in the long bones. It is characterized by dwarfism, limited range of motion at the elbows, macrocephaly, and small fingers. Achondroplasia can cause health complications such as apnea, obesity, recurrent ear infections, and lordosis. More serious problems include spinal stenosis and hydrocephalus. Some patients may have delayed motor development early on, but cognition is normal. Achondroplasia is caused by genetic changes in the FGFR3 gene.
Positive topline results from the PROPEL 3 clinical trial (NCT06164951) of oral infigratinib in children living with achondroplasia were recently announced. PROPEL 3 was a phase 3, global, one-year, randomized, double-blind, placebo-controlled study evaluating the efficacy and safety of infigratinib in children with achondroplasia, ages 3 to 18 years, with open growth plates.
Infigratinib is a selective, reversible, ATP-competitive tyrosine kinase inhibitor primarily targeting the fibroblast growth factor receptors FGFR1, FGFR2, and FGFR3.
Key results from the study through week 52 included a change from baseline in annualized height velocity (AHV) superior to placebo, with an LS mean treatment difference of +1.74 cm/year and a mean treatment difference of +2.10 cm/year. Absolute AHV at week 52 also showed a significant improvement with infigratinib compared to placebo. Change from baseline in height Z-score was superior to placebo, with an LS mean treatment difference of +0.32 standard deviations (SD) and the LS mean change from baseline on the treatment arm of +0.41 SD.
In an exploratory analysis of children younger than 8, oral infigratinib showed statistical significance against placebo in change from baseline in upper-to-lower body proportionality at week 52, demonstrating an LS mean decrease of -0.05 against placebo. In the overall population, infigratinib achieved an LS mean decrease of -0.05, with a favorable LS treatment difference of -0.02 versus placebo at week 52.
Infigratinib was well-tolerated, with no discontinuations and no serious adverse events related to the study drug.
Based on these results, plans for submission of a New Drug Application (NDA) and Marketing Authorization Application (MAA) for infigratinib are underway. BridgeBio is currently enrolling participants in the observational run-in for the phase 3 trial and has an ongoing clinical trial of infigratinib for the newborn to 3 year old age groups in achondroplasia in the PROPEL Infant & Toddler trial (NCT07169279).
For more information, visit https://www.globenewswire.com/news-release/2026/09/09/3358343/0/en/oral-infigratinib-shows-meaningful-benefits-beyond-growth-within-52-weeks-in-children-with-achondroplasia-in-the-phase-3-propel-3-trial.html
To learn more about achondroplasia and other rare musculoskeletal conditions, visit https://checkrare.com/diseases/musculoskeletal-diseases/