BridgeBio's oral achondroplasia drug shows growth and body proportionality gains in late-stage trial

BridgeBio Pharma (BBIO) said its experimental oral drug for achondroplasia improved not only growth but also body proportionality in children with the condition, a secondary benefit that analysts believe could distinguish the treatment from rival therapies for the most common form of dwarfism.

The company plans to submit a regulatory filing for the drug, infigratinib, in the third quarter, with a possible launch in early to mid-2027.

In the Phase 3 PROPEL 3 trial, more than 110 children with achondroplasia were randomized to receive either a daily dose of infigratinib or a placebo. Data presented showed the drug produced a statistically significant improvement in body proportionality versus placebo, in what BridgeBio described as the first such result achieved in the category. The trial also confirmed topline growth data released in February, with infigratinib patients showing a 2.1-centimeter-per-year advantage in annualized growth velocity over placebo.

Jefferies called the proportionality result "compelling," noting that competing therapies have not demonstrated statistical significance on that measure. The bank added that proportionality was likely to translate into meaningful gains in patients' mobility and daily function, and said it was optimistic the benefit would be reflected in the drug's eventual label.

Jefferies estimated peak sales for infigratinib in achondroplasia at $1 billion, calling an oral option with proportionality benefits "highly differentiated" against the injectable therapies currently on the market.

The data were presented as a late-breaking abstract at the 2026 International Congress of Children's Bone Health and published simultaneously in the New England Journal of Medicine.

Achondroplasia, a genetic disorder that impairs bone development and stunts growth, affects between one in 15,000 and one in 40,000 newborns. Associated complications include bowed legs, developmental delays, breathing difficulties and recurrent infections.

Two therapies are currently approved for the condition in the United States. BioMarin Pharmaceutical (BMRN) brought the first, a daily injection called Voxzogo, to market in November 2021. Ascendis Pharma (ASND) followed in March with Yuviwel, a weekly subcutaneous therapy that became the first once-weekly option approved by the Food and Drug Administration.

Competition from Ascendis has weighed on BioMarin. The company abandoned its target of $4 billion in revenue by 2027 in October 2025, citing competitive pressure on Voxzogo, which grew just three per cent year-on-year in the first quarter to $220mn.