HEMOFIL M- antihemophilic factor human
Baxter Healthcare Corporation
DESCRIPTION
HEMOFIL M, Antihemophilic Factor (Human) (AHF), Method M, Monoclonal Purified, is a sterile, nonpyrogenic, dried preparation of antihemophilic factor (Factor VIII, Factor VIII:C, AHF) in concentrated form with a specific activity range of 2 to 22 AHF International Units/mg of total protein. HEMOFIL M contains a maximum of 12.5 mg/mL Albumin, and per AHF International Unit, 0.07 mg polyethylene glycol (3350), 0.39 mg histidine as stabilizing agents, not more than 0.1 mg glycine, 0.1 ng mouse protein, 18 ng organic solvent (tri-n-butyl phosphate) and 50 ng detergent (octoxynol 9). In the absence of the added Albumin (Human), the specific activity is approximately 2,000 AHF International Units/mg of protein. [see Clinical Pharmacology ]
HEMOFIL M is prepared by the Method M process from pooled human plasma by immunoaffinity chromatography utilizing a murine monoclonal antibody to Factor VIII:C, followed by an ion exchange chromatography step for further purification. Source material may be provided by other US licensed manufacturers. HEMOFIL M also includes an organic solvent (tri-n-butyl phosphate) and detergent (octoxynol 9) virus inactivation step designed to reduce the risk of transmission of hepatitis and other viral diseases. The process further includes a nanofiltration step between immunoaffinity chromatography and ion-exchange chromatography as an additional viral clearance step to further improve the viral safety margin of the final product.
Use of an organic solvent (tri-n-butyl phosphate; TNBP) in the manufacture of Antihemophilic Factor (Human) has little or no effect on AHF activity, while lipid enveloped viruses, such as hepatitis B and human immunodeficiency virus (HIV) would be inactivated.1 The nanofiltration step integrated into the manufacture of AHF-M further enhances the safety margin with respect to adventitious viruses.
Each bottle of HEMOFIL M is labeled with the AHF activity expressed in International Units (IU) per bottle. This potency assignment is referenced to the World Health Organization International Standard.
The purity of HEMOFIL M has been thought to influence the difficulty of producing an accurate potency measurement. Experiments have shown that to achieve accurate activity levels, such a potency assay should be conducted using plastic test tubes and pipets as well as substrate containing normal levels of von Willebrand's Factor.
In vitro studies demonstrate that the HEMOFIL M, manufacturing process provides for significant viral reduction. These reductions are achieved through a combination of process chemistry, partitioning and/or inactivation during solvent/detergent treatment, and immunoaffinity chromatography. Introduction of a nanofiltration step with the 0.1�m prefilter and the ASAHI Planova 20N nanofilter provides a virus removal capacity for human immunodeficiency virus, Type 1 (HIV-1), hepatitis A virus (HAV), bovine viral diarrhea virus (BVDV), pseudorabies virus (PRV), mice minute virus (MMV), and human parvovirus B19 (B19V) in the order of four (4) logs or higher. B19V removal data were obtained with a Polymerase Chain Reaction (PCR) assay not correlated to an infectivity assay.
Studies for nanofiltration and other process steps, summarized in Table 1, demonstrate virus clearance during the HEMOFIL M manufacturing process using HIV-1; BVDV, a generic model for lipid enveloped RNA viruses, such as hepatitis C virus (HCV); PRV, a model for lipid enveloped DNA viruses, such as hepatitis B virus (HBV); canine parvovirus (CPV), a model for non-lipid enveloped DNA viruses, such as B19V, HAV, and MMV.
CLINICAL PHARMACOLOGY
Antihemophilic factor (AHF) is a protein found in normal plasma which is necessary for clot formation.
The administration of HEMOFIL M provides an increase in plasma levels of AHF and can temporarily correct the coagulation defect of patients with hemophilia A (classical hemophilia).
The half-life of HEMOFIL M administered to Factor VIII deficient patients has been shown to be 14.8 � 3.0 hours.
INDICATIONS AND USAGE
The use of HEMOFIL M is indicated in hemophilia A (classical hemophilia) for the prevention and control of hemorrhagic episodes.
HEMOFIL M is not indicated in von Willebrand's disease.