BioMarin announced on Mar. 16 that it is pausing dosing and enrollment in clinical trials of its drug Voxzogo for Turner syndrome, SHOX-deficiency, and aggrecan (ACAN) deficiency after several cases of slipped capital femoral epiphysis (SCFE) were reported in two ongoing investigator-sponsored studies.
The decision comes as BioMarin faces increased competition in the achondroplasia treatment market, following the recent approval of Ascendis Pharma’s Yuviwel by the Food and Drug Administration. SCFE is a condition where the head of the femur slips off at the growth plate, leading to pain and difficulty walking.
According to a filing with the Securities and Exchange Commission, BioMarin said that SCFE events have not been observed in its own Phase 2 trials for these conditions or among more than 5,000 infants and children treated with Voxzogo for achondroplasia. The company also stated that two other Phase 2 trials—one for hypochondroplasia and Noonan syndrome, and another for idiopathic short stature (ISS) without ACAN-deficiency—will continue as planned. ISS without ACAN-deficiency accounts for about 95% of children enrolled in that trial.
Voxzogo was approved by the FDA in November 2021 as the first drug to improve growth in children with achondroplasia. The company has since been developing it for additional growth-related disorders. However, BioMarin recently acknowledged during an earnings call that growing competition has led it to revise its revenue targets downward.
The competitive landscape is shifting as Yuviwel offers a weekly injection compared to Voxzogo’s daily regimen, potentially providing greater convenience for patients. BridgeBio is also advancing its own achondroplasia drug candidate, infigratinib, which showed strong results in a recent Phase 3 trial. BridgeBio plans to file a new drug application with the FDA later this year.
