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Hemophilia A
Studies from Bayer HealthCare provide new data on hemophilia a
November 6th, 2009
According to recent research published in the journal Blood, "Recombinant FVIII formulated in PEGylated liposomes (rFVIII-PEG-Lip) was reported to increase the bleed-free days from 7 to 13 days (at 35 IU/kg rFVIII) in severe hemophilia A patients. To understand the underlying mechanism, we sought to recapitulate its efficacy in hemophilia A mice." "Animals treated with rFVIII-PEG-Lip achieved approximately 30% higher survival relative to rFVIII after tail vein transection inflicted 24 hours after dosing. The efficacy of rFVIII-PEG-Lip represents an approximately 2.5-fold higher ''apparent'' FVIII activity, which is not accounted for by its modestly increased (13%) half-life. The enhanced efficacy requires complex formation between rFVIII and PEG-Lip before the administration. Furthermore, PEG-Lip associates with the majority of platelets and monocytes in vivo, and results in increased P-selectin surface expression on platelets in response to collagen. Rotational thromboelastometry (ROTEM) analysis of whole blood from rFVIII-PEG-Lip-treated animals at 5 minutes up to 72 hours after dosing recapitulated the 2- to 3-fold higher apparent FVIII activity. The enhanced procoagulant activity is fully retained in plasma unless microparticles are removed by ultracentrifugation," wrote J.L. Pan and colleagues, Bayer HealthCare. The researchers concluded: "Taken together, the efficacy of rFVIII-PEG-Lip is mediated mainly by its sensitization of platelets and the generation of procoagulant microparticles that may express sustained high-affinity receptors for FVIII. (Blood. 2009;114:2802-2811)." Pan and colleagues published their study in Blood (Enhanced efficacy of recombinant FVIII in noncovalent complex with PEGylated liposome in hemophilia A mice. Blood, 2009;114(13):2802-2811). For additional information, contact H.Y. Jiang, Bayer HealthCare LLC, Applied Research, 2600 Hilltop Dr., Richmond, CA 94806, USA. The publisher's contact information for the journal Blood is: American Society Hematology, 1900 M Street. NW Suite 200, Washington, DC 20036, USA. Keywords: United States, Richmond, Bayer Healthcare AG, Biotechnology, Gene Therapy, Hemophilia A, Pharmaceutical Business, Pharmaceutical Company, Bayer HealthCare. This article was prepared by NewsRx editors from staff and other reports. Copyright 2009, NewsRx.com.
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