BioMarin's Investigational Gene Therapy for Hemophilia A Maintains Average Factor VIII Levels within Normal Range for over One Year

Note: The following is an edited version of a press release from BioMarin. Read the press release from BioMarin in it’s entirety here.

BioMarin Pharmaceutical Inc. announced an update to its previously reported interim results of an open-label Phase 1/2 study of BMN 270, an investigational gene therapy treatment for severe hemophilia A. The updated results were presented during an oral presentation at the International Society on Thrombosis and Haemostasis (ISTH) 2017 Congress being held July 8-13, 2017 in Berlin, Germany.  It was the only clinical data in gene therapy for hemophilia A to be presented at the meeting.
In the open-label Phase 1/2 study, a total of 15 patients with severe hemophilia A received a single dose of BMN 270, seven of whom were treated at a dose of 6e13 vg/kg and an additional six of whom were subsequently treated at a lower dose of 4e13 vg/kg.  The other two patients in the study were treated at lower doses as part of dose escalation in the study and did not achieve therapeutic efficacy.  As of the May 31, 2017 data cutoff, all patients at the 6e13 vg/kg dose had reached 52 weeks of post-treatment follow-up.  Median and mean Factor VIII levels from week 20 through 52 for the 6e13 vg/kg dose cohort have been consistently within the normal levels post treatment as a percentage calculated based on the numbers of International Units per deciliter (IU/dL) of plasma. At one year after dosing, the median and mean Factor VIII levels of the 6e13 vg/kg cohort continue to be above 50%.