rVIII-SingleChain (recombinant factor VIII single-chain) filed with FDA for haemophilia A- CSL Behring

The FDA has accepted for review a Biologics License Application for rVIII-SingleChain (recombinant factor VIII single-chain), from CSL Behring, for the treatment of haemophilia A. In the pivotal clinical trial, rVIII-SingleChain met all primary endpoints.

The BLA submission is based on the AFFINITY clinical development program, which includes a phase I/III open-label, multi-center trial examining safety and efficacy. The pharmacokinetics of rVIII-SingleChain compared with recombinant human antihemophilic factor VIII (octocog alfa) was also studied.

Results from the phase I/III study were presented at the International Society on Thrombosis and Haemostasis congress in Toronto. Patients treating prophylactically had a median annualized bleeding rate of 1.14 and a median annualized spontaneous bleeding rate of 0.00. The data also showed that, of 848 bleeds treated in the study, 94 percent were controlled with no more than two infusions of rVIII-SingleChain, with 81 percent controlled by one infusion. Moreover, hemostatic control of a bleeding event treated with rVIII-SingleChain was assessed by the investigator as excellent or good 94 percent of the time (835 assessed bleeding events).