Bayer HealthCare recently reported on preclinical data suggesting that a pegylated form of recombinant factor VIII (rFVIII) could have longer-lasting therapeutic effects. The company presented three scientific abstracts at the 21st Congress of the International Society on Thrombosis and Haemostasis (ISTH) held July 6-12 in Geneva, Switzerland, highlighting promising results of Bayer-administered studies of the new formulation using mouse models.
A protein molecule, in this case human FVIII, is attached with polyethylene glycol (PEG), or pegylated, to prolong its presence inside the body. By using this process, Bayer plans to produce an enhanced hemophilia A therapy that offers extended protein activity and prevention from bleeding. Since pegylated proteins are less susceptible to antibodies, they are also not as likely to be neutralized by inhibitors.
"Developing a longer-acting FVIII product is high on Bayer's priority list, and the positive findings from our preclinical studies presented this week represent a major step forward," said Glenn Pierce, MD, PhD, vice president, Applied Research and U.S. Medical Affairs, Hematology/Cardiology, Bayer HealthCare Pharmaceuticals.
In preclinical studies using mouse models with hemophilia A, pegylated FVIII molecule (PEG-FVIII) showed prolonged bleeding protection compared to rFVIII alone. Mice injured 48 hours after treatment with PEG-FVIII exhibited less bleeding (30%) than those injured 24 hours after rFVIII treatment minus pegylation (77%). Pharmacokinetic studies showed approximately double the increase in half-life for the pegylated rFVIII versus rFVIII alone. In addition, PEG-FVIII demonstrated greater resistance to inhibitors than FVIII in four of the eight patient plasma samples tested.
The three Bayer HealthCare abstracts presented during the ISTH Congress were:
- "Site-Specific PEGylation of rFVIII Results in Prolonged in Vivo Efficacy"
- "Evaluation of PEG-FVIII Molecules with Prolonged Half-Lives in a Murine FVIII-Dependent Bleeding Model"
- "PEGylation Protects Factor VIII from the Inhibition of Antibody Inhibitors"
Source: PRNewswire, July 12, 2007