KING OF PRUSSIA, Pa., June 4, 2013 /PRNewswire/ -- CSL Behring has dosed the first patient in Part 3 of its AFFINITY clinical trial program, which is now in phase III. AFFINITY is an open-label, non-randomized, multi-center study evaluating the efficacy, safety and pharmacokinetics of its novel investigational recombinant coagulation single-chain factor VIII (rVIII-SingleChain) for the treatment of hemophilia A. The patient was dosed in Vienna, Austria and had a successful major surgery. (Logo: http://photos.prnewswire.com/prnh/20100914/PH63692LOGO ) The CSL Behring rVIII-SingleChain is a novel recombinant single-chain Factor VIII design that uses a strong, covalent bond that has been shown to improve the stability and half-life of factor VIII (FVIII). A recombinant factor therapy option with a longer half-life could provide a longer dosing interval, leading to less frequent injections. This may have the potential to improve compliance and ease prophylaxis, improving the quality of life for people with hemophilia A. "We are proud and excited that this recombinant coagulation factor development program is progressing into Phase III clinical studies and look forward to sharing the clinical trial results for our novel rVIII-SingleChain molecule with the hemophilia community in the future," said Russell Basser, M.D., CSL Senior Vice President, Global Clinical Research & Development. "As part of our ongoing commitment to the hemophilia community, we are developing and investigating innovative recombinant factor therapies for the treatment of both hemophilia A and B that have the potential to offer patients and caregivers significant advances in treatment and convenience of factor infusion." CSL Behring, in collaboration with its parent company, CSL Limited (ASX: CSL), is developing rVIII-SingleChain through the AFFINITY clinical trial program. About the AFFINITY Phase I/III Study The Phase I/III study is an open-label, multi-center trial that examines the crossover safety, efficacy and pharmacokinetics of recombinant coagulation single-chain factor VIII compared with recombinant human antihemophilic factor VIII (octocog alpha). In Part 1 of the study, 27 subjects received a single infusion of 50 IU/kg body weight (b.w.) of octocog alfa followed by a single infusion of 50 IU/kg b.w. rVIII-SingleChain. Results of Part 1 of the study will be presented at the 2013 International Society on Thrombosis and Haemostasis in Amsterdam, Netherlands on 2 July. In Parts 2 and 3 of the study, subjects will receive infusions of rVIII-SingleChain to prevent and treat bleeding (if required), at a dose and frequency determined by their study doctor (based on the subject's underlying bleeding phenotype). More information about the study design can be found at www.clinicaltrials.gov. Recombinant FVIII molecules so far available consist of a heavy and a light chain. Under certain conditions, these chains can dissociate, resulting in the formation of separated, or "dissociated," rFVIII chains that are not hemostatically active. The CSL Behring rVIII-SingleChain uses a strong, covalent bond that connects the light and heavy chains, thereby creating a stable single chain rFVIII.