Four years after BioMarin Pharmaceutial's vosoritide posted proof-of-concept data, the drug hit the mark in phase 3, helping children with achondroplasia, the most common form of dwarfism, grow more quickly than those on placebo. The company will discuss the drug’s path to market with regulators early next year, and analysts anticipate a 2021 launch.
The study pitted vosoritide against placebo in 121 children aged five to 14 who have the genetic disorder and whose growth plates are still open. Over one year, the treatment improved growth velocity from baseline by 1.6 cm after adjusting for placebo. The study also looked at a range of secondary endpoints, including the proportionality of limbs to the body, joint geometry and quality of life measures.
Achondroplasia is caused by a mutation in the fibroblast growth factor receptor 3 gene. Short stature from the failure of cartilage to turn into bone is the most recognizable symptom, but people with achondroplasia can also face serious health issues such as sleep apnea or spinal stenosis, in which the narrowing of the spine puts pressure on spinal nerves. Some patients may need surgery to reduce pressure on those nerves or to straighten bowed legs.
"These results when combined with the long-term benefits seen in the phase 2 study provide hope for a significant and sustained benefit for children with achondroplasia,” Hank Fuchs, M.D., BioMarin’s R&D chief, said in a statement.
If the drug can win approval—following a meeting with regulators coming in the first half of next year—Jefferies analyst Eun Yang expects uptake to be quick.
“Ph3 success for vosoritide comes in line with expectations, clearing the path forward for a commercial launch in 2021. Potentially as the first drug for achondroplasia (the most common form of short stature), we expect rapid uptake, if approved (~50% penetration in the first year of availability per expert vs. our est. <20%),” Yang wrote in a note to clients Monday.