FDA’s decision on BMN 270, also known for its generic name valoctocogene roxaparvovec, was supported by clinical data of the Phase 1/2 trial (NCT02576795) conducted in the United Kingdom, and the protocols of future Phase 3 trials on BMN 270.
The ongoing Phase 1/2 trial is evaluating BMN 270’s safety, and efficacy to restore levels of the protein Factor VIII that plays a crucial role in blood clotting and prevent bleeding events in patients with severe hemophilia A. Six patients received intravenously a single 4e13 vg/kg dose of BMN 270, and seven patients received a 6e13 vg/kg dose.
Follow-up data at 36 weeks after treatment with the 4e13 vg/kg dose showed that 5 patients achieved levels of Factor VIII that meet the low range of normal. The sixth treated patient reached the mild range for Factor VIII levels. Four weeks after treatment, the annual Factor VIII administration rates and median annualized bleeding rates were zero.
These results follow the positive trend already demonstrated in earlier clinical data assessments.
To date, BMN 270 therapy has demonstrated overall that it is safe and well-tolerated by patients. There were no reports of patients developing natural inhibitors to Factor VIII, and no patients had to leave the study due to secondary adverse effects.
The most common adverse events reported were increased liver enzymes, joint pain, headache, back pain, and fatigue. No complications were reported. One patient developed a treatment-related serious adverse event that required hospitalization, but it was resolved within the following 48 hours after suitable care. No treatment recurrent complications were reported.
“We are pleased to share the progress of our development programs in therapies to treat rare genetic diseases,” Hank Fuchs, MD, president worldwide research and development of BioMarin, said in a press release. “We continue to be rapidly and decisively developing the potential first gene therapy for severe hemophilia A.”
The company is planning to initiate the global Phase 3 program on BMN 270 during the fourth quarter of 2017. The UK Medicines and Healthcare Products Regulatory Agency (MHRA) has already approved the Phase 3 Clinical Trial Application.