Breakthrough Therapy Status for Hemophilia A Treatment

BioMarin Pharmaceutical is developing valoctocogene roxaparvovec

Valoctocogene roxaparvovec (formerly BMN 270, BioMarin Pharmaceutical Inc.) has received the FDA’s breakthrough therapy designation as a potential treatment for hemophilia A.

The FDA's breakthrough therapy program aims to speed development and review of new drugs to address unmet medical need in the treatment of a serious condition. Preliminary clinical evidence must show that that the drug may demonstrate substantial improvement over existing therapies. This designation was granted based on data from an ongoing BioMarin phase 1/2 study evaluating safety and efficacy of valoctocogene roxaparvovec.

BioMarin expects to initiate enrollment of a global phase 3 program before the end of 2017. The program includes two studies with valoctocogene roxaparvovec, one with the 4e13 vg/kg dose and one with the 6e13 vg/kg dose. The studies will each likely include approximately 40 patients.

BioMarin's valoctocogene roxaparvovec has also received an orphan drug designation from the FDA for the treatment of hemophilia A.

Hemophilia A, also called factor VIII deficiency or classic hemophilia, is a genetic disorder caused by missing or defective factor VIII, a clotting protein. Although it is passed down from parents to children, about one-third of cases are caused by a spontaneous mutation, a new mutation that was not inherited. As an X-linked disorder, hemophilia A mostly affects males, occurring in approximately one in 5,000 male births. People living with the disease are not able to form blood clots efficiently and are at risk for excessive bleeding from modest injuries, potentially endangering their lives.

Gene therapy is designed to alter a genetic problem by adding a corrected copy of the defective gene. The functional gene is inserted into a vector—containing a DNA sequence coding for a specific protein—that acts as a delivery mechanism, providing the ability to deliver the functional gene to cells. The cells can then use the information to build the functional protein that the body needs, potentially reducing or eliminating the cause of the disease.

Source: BioMarin, October 26, 2017.