BioMarin Pharmaceutical has reported positive three-year data from an ongoing Phase I/II trial of its investigational gene therapy valoctocogene roxaparvovec.
Developed to treat adults with severe haemophilia A, the drug has secured breakthrough therapy designation from the US Food and Drug Administration (FDA) and priority medicines (PRIME) access from the European Medicines Agency (EMA).
The therapeutic also received orphan drug designation from both regulators.
According to the study results, bleed rate control with 6e13vg/kg dose of the gene therapy was sustained at three years, with a median annualised bleed rate (ABR) of 0 and a mean ABR of 0.7.
The mean ABR is said to represent a 96% reduction over three years.
Data showed that 71%, 86% and 86% of patients had zero bleeds requiring Factor VIII (FVIII) infusions in the first, second and third years, respectively. This demonstrates an improvement from 14% in the year prior to study enrolment.
In addition, a 96% decrease in mean FVIII usage was observed over three years. In the first, second and third years, the mean FVIII usage reduction was 98%, 94% and 96%, respectively.
BioMarin Pharmaceutical global research and development (R&D) president Hank Fuchs said: “These data confirm that valoctocogene roxaparvovec has the potential to profoundly impact the lives of people with severe haemophilia A through a sustained reduction in bleeds and FVIII usage.
“More conservative statistical modelling anticipates that bleeding control will be maintained for at least eight years after gene transfer.”
BioMarin CEO Jean-Jacques Bienaime said that the value of valoctocogene roxaparvovec could be $2m based on the cost of five years of the current standard-of-care treatment, reported Reuters.
The company is currently conducting six clinical studies as part of its comprehensive gene therapy programme for severe haemophilia A treatment.