Oral infigratinib linked to improved growth and proportionality in achondroplasia

Oral infigratinib (Truseltiq;BridgeBio) has displayed significant improvements in body proportionality among children aged 3 to 8 years with achondroplasia in a phase 3 trial, according to BridgeBio.¹

The PROPEL 3 trial was conducted to evaluate the change in annualized height velocity (AHV) among pediatric patients receiving oral infigratinib. The medication showed superiority in this outcome vs placebo, with an LS mean treatment difference of 1.74 cm per year and a mean treatment difference of 2.10 cm per year.¹

"Achondroplasia is a genetic condition driven by FGFR3 that affects more than stature alone, with consequences on physical functioning and independence that can impact widely over a person’s lifetime,” said Ravi Savarirayan, MD, PhD, lead investigator and researcher at Murdoch Children’s Research Institute.¹

Secondary endpoints show additional growth benefits

Participants of the 1-year, 2:1 randomized, double-blinded placebo-controlled trial included children aged 3 to less than 18 years with achondroplasia and open growth plates. Outcomes were reported at week 52 of treatment, with changes from baseline compared between the infigratinib and placebo groups.¹

Alongside the study’s primary endpoint, significant improvements in secondary endpoints were reported in the infigratinib group. This included absolute AHV at week 52, with a greatest mean absolute AHV of 5.96 cm per year. In comparison, the greatest mean absolute AHV was 4.22 cm per year in the placebo group.¹

Superiority was also reported for infigratinib in the change from baseline in height Z-score, with an LS mean treatment difference of 0.32 standard deviation. Infigratinib was the first therapeutic option to show a significant decline in upper-to-lower body proportionality among children aged under 8 years at week 52 of -0.05 vs placebo.¹

In the overall population, the LS mean decrease was -0.05. Additionally, a favorable LS treatment difference of -0.02 was reported at week 52 vs placebo.¹

Favorable safety and ongoing research reported

Positive tolerance results were also reported. There were no discontinuations or serious adverse events related to the study drug. Four percent of patients presented with mild hyperphosphatemia not requiring dose reductions or discontinuation. FGFR1 or FGFR2 inhibition was also not linked to adverse events.¹

Additionally, there were no adverse events linked to C-type natriuretic peptide analogues. These include symptomatic hypotension, injection site reactions, and hypertrichosis. Overall, these results indicated that oral infigratinib is well-tolerated in a pediatric population.¹

A phase 2 trial is also being conducted to evaluate the safety and efficacy of infigratinib in patients with achondroplasia aged under 3 years.² The researchers hope to determine the dose of infigratinib that may be used in this population.

Disease burden and therapeutic significance

Achondroplasia impacts approximately 55,000 US and European Union patients, including up to 10,000 pediatric patients with open growth plates.¹ Patients with this condition may experience obstructive sleep apnea, middle ear dysfunction, spinal stenosis, and kyphosis. Infigratinib is the first medication to show significant improvements in outcomes vs placebo.

“Infigratinib is the first oral therapy designed to target FGFR3 and directly address the underlying cause of achondroplasia. In the broadest age range studied to date, oral infigratinib has demonstrated the highest and most significant improvement in annualized growth velocity,” said Savarirayan.¹

References

1. BridgeBio reports positive phase 3 topline results for oral infigratinib with the first statistically significant improvements in body proportionality in achondroplasia. BridgeBio. February 12, 2026. Accessed February 12, 2026. https://investor.bridgebio.com/news/news-details/2026/BridgeBio-Reports-Positive-Phase-3-Topline-Results-for-Oral-Infigratinib-with-the-First-Statistically-Significant-Improvements-in-Body-Proportionality-in-Achondroplasia/default.aspx
2. Interventional study of infigratinib in children < 3 years old with achondroplasia (ACH). ClinicalTrials.gov. Accessed February 12, 2026. https://clinicaltrials.gov/study/NCT07169279?cond=achondroplasia%20infigratinib&limit=10&sort=@relevance&rank=3