Study Shows Feasibility Of Developing Half-Life Extended Recombinant FVIIa

CSL Behring announced the results of a pre-clinical study that show for the first time it is feasible to genetically fuse Factor VIIa (FVIIa) to human albumin, prolonging the half- life of this therapeutic protein while retaining its biologic activity. In the study, which was presented at the American Society of Hematology 49th Annual Meeting and Exposition, the half-life of recombinant VIIa-albumin fusion protein (rVIIa-FP) was shown to be extended 6-to-9 fold compared to wild type rFVIIa. Additionally, rVIIa-FP demonstrated a biologic activity comparable to wild type rFVIIa.

Recombinant factor VIIa (rFVIIa) may be used to control bleeding episodes in hemophilia patients with inhibitors. These patients develop an immune response that inhibits the substituted clotting factor from stopping a bleeding episode. However, rFVIIa has a short half-life of approximately 2.5 hours. This necessitates multiple injections, which are inconvenient for both physicians and patients, particularly during surgical intervention.

"A major unmet need in hematology is improving the pharmacokinetic parameters of coagulation factors, such as half-life, while retaining full hemostatic activity," said Dr. Stefan Schulte, Head Pre-clinical R&D, CSL Behring GmbH and lead investigator of the study. "The pharmacological properties of rVIIa-FP seen in our study could one day facilitate a single dosing regimen of one injection per bleeding event, as well as significantly reduce the number of injections hemophilia patients with inhibitors need during surgical interventions."

Recombinant VIIa-FP represents CSL Behring's initial corporate foray into research with recombinant coagulation product technology.

"CSL Behring is pleased to be at the forefront of this exciting development in hemophilia treatment, which is consistent with our mission to improve the lives of patients with bleeding disorders," said Dr. Andrew Cuthbertson, Chief Scientific Officer at CSL Ltd., parent company of CSL Behring. "By increasing convenience and compliance, rVIIa-FP has the potential to benefit hemophilia patients with inhibitors and the physicians who treat those patients. We look forward to continuing our research and accumulating additional data to validate the results seen in our pre-clinical study of this molecule."