BeneFIX, Coagulation Factor IX (Recombinant), is a purified protein produced by recombinant DNA technology. The product is formulated as a sterile, non-pyrogenic, lyophilized powder preparation intended to be reconstituted for intravenous injection. It is available in single-use vials containing the labeled amount of factor IX activity, expressed in International Units (IU). Each vial contains nominally 250, 500, 1000, 2000, or 3000 IU of recombinant coagulation factor IX. The potency (in IU) is determined using an in vitro one-stage clotting assay against the World Health Organization (WHO) International Standard for Factor IX concentrate. One IU is the amount of factor IX activity present in 1 mL of pooled, normal human plasma. After reconstitution of the lyophilized drug product, the concentrations of excipients are 0.234% sodium chloride, 8 mM L-histidine, 0.8% sucrose, 208 mM glycine, 0.004% polysorbate 80. The specific activity of BeneFIX is greater than or equal to 200 IU per milligram of protein. BeneFIX contains no preservatives and all dosage strengths yield a clear, colorless solution upon reconstitution.
Coagulation factor IX is the active ingredient in BeneFIX. It has a primary amino acid sequence that is identical to the Ala148 allelic form of human factor IX, and has structural and functional characteristics similar to those of endogenous factor IX.
BeneFIX is not derived from human blood. It is produced by a genetically engineered Chinese hamster ovary (CHO) cell line that is extensively characterized. No additives of animal or human origin are used during the cell culture, purification, and formulation processes of BeneFIX. The stored cell banks are free of human blood or plasma products. The CHO cell line secretes recombinant factor IX into a defined cell culture medium, and the recombinant factor IX is purified by a four-step chromatography purification process that does not require a monoclonal antibody step. The process also includes a membrane nanofiltration step that has the ability to retain molecules with apparent molecular weights >70,000 Da (such as large proteins and viral particles). BeneFIX is a single component by SDS-polyacrylamide gel electrophoresis evaluation.