Abstract: Processes for improving the in vivo function of factor VIII by shielding exposed targets of the factor VIII comprise a) immobilizing the factor VIII by interaction with a group-specific adsorbent carrying ligands manufactured by organic-chemical synthesis, for preventing polymer coupling to reactive amino acids of the immobilized factor VIII, within or adjacent to interaction domains; b) activating a biocompatible polymer; c) conjugating the activated biocompatible polymer to external sites of the immobilized factor VIII; and thereafter d) eluting the conjugate from the adsorbent. Processes for administering factor VIII comprise subcutaneously, intramuscularly, intradermally or intravenously administering a conjugate of factor VIII and a biocompatible polymer, and methods for treatment of hemophilia A comprise subcutaneous, intramuscular, intradermal or intravenous administration of a conjugate of factor VIII and a biocompatible polymer.

Abstract: The present invention relates to a process for purifying recombinant coagulation factor VIII by loading an aqueous solution containing factor VIII onto a hydrophobic interaction chromatography (HIC) gel, wherein at least one surfactant is present in the aqueous solution and/or a buffer solution used to equilibrate the gel prior to loading the aqueous solution onto the gel. The presence of a surfactant when loading the solution containing factor VIII onto the HIC gel, makes it possible to efficiently separate the intact and active factor VIII molecules from molecules with structural deviations. With the present invention it is further possible to reduce the content of DNA and/or CHO cell contaminants considerably and increase the activity of the factor VIII product to a hitherto unknown extent.

Abstract: A process for reducing degradation of recombinant coagulation factor VIII caused by metal-dependent proteases requiring Zn.sup.2+ for activity or containing Zn.sup.2+ as an integral part of their structure comprises adding an inhibitor of Zn.sup.2+ dependent proteases to a recombinant factor VIII solution. The recombinant factor VIII solution is obtained after harvesting a conditioned medium from a cell culture used for producing the recombinant coagulation factor VIII. The inhibitor is selected from complexing agents with a stronger affinity for the Zn.sup.2+ ion of the protease than for the ion or ions stabilizing the factor VIII molecule, and compounds structurally related to the natural substrate of the protease and containing an electronegative moiety.