Baxter Initiates Phase I Clinical Trial of Longer-Acting Recombinant FVIII Treatment for Hemophilia A

Baxter International Inc.

today announced the dosing of the first patients in a Phase I clinical trial of its lead investigational candidate, BAX 855, a longer-acting (PEGylated) form of a full-length recombinant factor VIII (rFVIII) protein. BAX 855 is based on Baxter's ADVATE [Antihemophilic Factor (Recombinant) Plasma/Albumin-Free Method] full-length rFVIII molecule and plasma/albumin-free manufacturing process. The Phase I trial is a prospective, open-label study that will assess the safety, tolerability and pharmacokinetics of BAX 855 in previously-treated patients aged 12 years or older with severe hemophilia A. When used for prophylaxis, Baxter's ADVATE requires patients to infuse every two to three days to reduce the occurrence of bleeding episodes. This Phase I trial is the first step in assessing whether BAX 855 can be infused less frequently. BAX 855 employs Baxter's proprietary full-length plasma/albumin-free recombinant protein platform that does not contain any human or animal-derived additives. BAX 855 leverages Nektar Therapeutics'

proprietary PEGylation technology, which is designed to extend the duration of activity of proteins and larger molecules. Baxter and Nektar have a collaboration to develop PEGylated products designed to provide new long-acting therapies for hemophilia patients. ADVATE was recently approved for routine prophylaxis to prevent or reduce the frequency of bleeding episodes