Note: The below is an edited press release from CSL Behring. To read the full release, click here.
CSL Behring announced that the U.S. Food and Drug Administration has accepted for review the company’s Biologics License Application (BLA) for its novel investigational recombinant factor VIII single-chain (rVIII-SingleChain) for the treatment of hemophilia 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. Study design details for rVIII-SingleChain are available at clinicaltrials.gov.
Results from the phase I/III study were recently presented at the International Society on Thrombosis and Haemostasis (ISTH) congress in Toronto. Patients treating prophylactically had a median annualized bleeding rate (ABR) of 1.14 and a median annualized spontaneous bleeding rate (AsBR) 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).
The results presented included data on more than 14,000 exposure days in 146 patients on prophylaxis and 27 patients treating on demand for a bleeding event. In total, 120 patients were treated for more than 50 days of exposure; 52 had more than 100 days of exposure. In the prophylaxis group, 32 percent of patients were dosed twice weekly and 54 percent received treatment three times per week; the regimen was determined by the investigator. The most common adverse events were naso-pharyngitis, arthralgia, and headache. No inhibitors were reported.
Specifically designed for greater molecular stability, rVIII-SingleChain is the first and only single-chain factor VIII (FVIII) product in late-stage development for the treatment of hemophilia A. rVIII-SingleChain (also known as CSL627) has a strong affinity for von Willebrand factor, leading to greater stability and integrity of FVIII in circulation. For more information about CSL Behring’s recombinant products in development to treat hemophilia, visit http://www.cslbehring.com/products/bleeding-disorders/novel-recombinant-hemophilia-treatments.