BridgeBio touted longer-term data for its achondroplasia drug infigratinib from a mid-stage trial on Tuesday, setting the treatment up to be a future competitor for BioMarin’s Voxzogo, the first and only approved drug for the most common form of dwarfism.
The PROPEL 2 trial investigated infigratinib, an FGFR inhibitor, in children with achondroplasia. Patients saw “sustained and statistically significant” mean increases in annual height of 2.51 centimeters from baseline after 12 months, and 2.50 centimeters of growth at 18 months, earning a p=0.0015 for both time points.
Participants also saw a “statistically significant” improvement in body proportionality — the ratio between the upper and lower body — of 2.02 at baseline to 1.88 after 18 months, earning a p=0.001.
“These data indicate that treatment with infigratinib is continuing to show increased growth velocity and improvements in body proportionality in children with achondroplasia,” said PROPEL 2 global lead investigator Ravi Savarirayan, a doctor at Murdoch Children’s Research Institute in Melbourne, Australia. “This is encouraging and suggests that infigratinib has the potential to enhance functionality for people living with achondroplasia in addition to increasing growth,” Savarirayan added in a press release.
In earlier six-month data presented last year, infigratinib showed a 3.38 mean increase in height velocity, earning a p=0.001. The drug is already in a Phase 3 trial in achondroplasia, with enrollment expected to be completed by the end of this year.
The drug will potentially compete with Voxzogo, with Jefferies analysts writing in a May 31 note that they already expected Voxzogo’s achondroplasia market territory to decline in 2027 due to the potential entry of infigratinib in the market. Stifel analysts wrote on May 27 that they also expect BridgeBio’s drug to be the “biggest competitive threat” to Voxzogo in achondroplasia.
However, Voxzogo will already be a $1.2 billion drug in achondroplasia by the time infigratinib is likely to enter the market, the Jefferies analysts added. Voxzogo brought in net revenues of $153 million in the first quarter of 2024, according to BioMarin’s latest financial report.
Infigratinib is also being investigated in a Phase 2 trial in children with hypochondroplasia, a skeletal dysplasia, that could lead to a Phase 3 study that will look at changes in annualized height velocity from baseline as well as other growth markers like body proportion and quality-of-life changes.
BridgeBio CMO Daniela Rogoff said in a statement that Tuesday’s data have the company “especially encouraged by the promising effect on body proportions, which supports infigratinib’s potential to provide benefits that could impact the lives of children with achondroplasia.”
“These results motivate us to continue evaluating infigratinib in other FGFR-related skeletal dysplasias and genetic conditions,” Rogoff added. “The initiation of our observational study in hypochondroplasia and the obtainment of FDA and EMA alignment on the interventional study underlies our excitement for the potential of infigratinib as a treatment option for children with hypochondroplasia.”