AMSTERDAM, July 2, 2013 /PRNewswire/ -- CSL Behring today announced that pharmacokinetic results for its novel investigational recombinant coagulation single-chain factor VIII (rVIII-SingleChain) showed improved half-life over octocog alfa (the comparator). It also demonstrated a safety and efficacy profile that supports advancement to late-stage clinical development. The data were presented at the International Society on Thrombosis and Haemostasis (ISTH) congress in Amsterdam. (Logo: http://photos.prnewswire.com/prnh/20130627/NY39350LOGO ) CSL Behring, in collaboration with its parent company, CSL Limited (ASX:CSL), is developing rVIII-SingleChain for the treatment of hemophilia A as part of the AFFINITY clinical trial program. "These data are promising and suggest that the recombinant single-chain design for Factor VIII may help address the need for a hemophilia A treatment with a longer half-life," said Professor Ingrid Pabinger-Fasching, M.D., of the Medical University of Vienna, Austria. "A treatment with an improved half-life has the potential to increase the quality of life for those with severe hemophilia A by reducing the number of factor VIII protein infusions required to restore normal blood clotting." The CSL Behring rVIII-SingleChain design uses a strong, covalent bond shown to improve the stability and half-life of factor VIII (FVIII). The investigational treatment is currently being studied in a Phase III trial. "As part of our commitment to developing effective therapies to treat hemophilia, we sought to develop a novel recombinant single-chain Factor VIII design that improves the stability and half-life of factor VIII," said Russell Basser, M.D., CSL Senior Vice President, Global Clinical Research & Development. "We are encouraged by these clinical results and very pleased that our investigation of rVIII-SingleChain molecule has progressed to Phase III." About the Pharmacokinetic Study The study enrolled 27 participants >18 years old with severe hemophilia A. Study participants had pharmacokinetic (PK) measurements performed over 72 hours for both octocog alfa and rVIII-SingleChain after they had received a single infusion of 50 IU/kg body weight of each of the compounds, respectively. In between study drug administration there was a 4-day minimum washout phase. Study objectives comprised the characterization of the PK profile of rVIII-SingleChain, the PK comparison of rVIII-SingleChain to octocog alfa and the characterization of the safety profile of rVIII-SingleChain. The pharmacokinetics of rVIII-SingleChain and octocog alfa were assessed on the basis of FVIII activity. The following PK parameters were calculated for baseline-corrected FVIII activity using a non-compartmental model analysis with WinNonlin Phoenix (Version 6.3): The area under the plasma activity-time curve from time zero to the last quantifiable concentration (AUClast); the area under the plasma activity-time curve from time zero to infinity (AUCinf); the observed maximum plasma activity after drug administration (Cmax); incremental Recovery (IU/mL/IU/kg) defined as FVIII activity (IU/mL) obtained 30 minutes following infusion; clearance (CL), and terminal elimination half-life (t½).