- BridgeBio Pharma’s shares soared nearly 60% early Monday after the company released new data on its experimental drug infigratinib in children with a disorder known as achondroplasia that causes dwarfism.
- The Californian biotech found that a high dose of the drug increased average “annualized height velocity” by about 3 centimeters among 10 children followed for six months. That compares with 1.5 cm on what was previously the highest tested dose in results disclosed in July.
- The Phase 2 study suggests infigratinib could offer the best efficacy in its class along with a “clean safety profile,” BridgeBio said Monday. BioMarin Pharmaceutical’s approved medicine Voxzogo, which has been tested more extensively, improved annualized growth velocity in patients in a Phase 3 study by 1.57 cm after a year.
Based on the latest data, BridgeBio has started enrolling children in a Phase 3 trial of infigratinib in achondroplasia and also plans to develop the medicine for patients with a closely related skeletal abnormality known as hypochondroplasia.
The company has a high bar to meet. Though achondroplasia can cause health complications beyond short stature, it’s not life-threatening. The Cleveland Clinic advises parents of children diagnosed with the condition that it “won’t hinder your child’s ability to live a happy and healthy life.”
As a result, doctors and parents will be focused on future results that show any side effects from the use of infigratinib. The safety profile of BioMarin’s option is one of its major selling points, Stifel analyst Paul Matteis wrote in a note to investors.
BridgeBio didn’t detail the adverse events experienced by patients in the latest group, but said that there were none assessed as treatment-related. If the data holds up in the Phase 3 trial and BridgeBio continues to see this kind of efficacy, the company will have a major advantage over BioMarin, Mizuho Securities analyst Salim Syed wrote to his clients. “Saying that the data is a win may be an understatement,” he said.
“This drug has our attention,” added Piper Sandler analyst Christopher Raymond, but “it remains to be seen if the relatively clean profile to date bears out with longer-term follow-up.”
BridgeBio may also have an advantage on the means of administering its medicine. Infigratinib is a once-daily oral treatment, while BioMarin’s Voxzogo requires an injection.
Achondroplasia is caused by an alteration in a gene called FGFR3, which makes a protein involved in bone growth and development. Infigratinib is designed to block the gene.
Achondroplasia affects about 55,000 people in the U.S. and European Union, according to BridgeBio. That includes as many as 10,000 children and adolescents who have open growth plates, meaning they could continue to grow. The average age in the latest group of children tested was 7.24 years old, BridgeBio said.