Alphanate Description

Antihemophilic Factor/von Willebrand Factor Complex (Human), Alphanate sterile, lyophilized concentrate of Factor VIII (AHF) and von Willebrand Factor (VWF), is intended for intravenous administration in the treatment of hemophilia A, acquired Factor VIII deficiency, and von Willebrand Disease (VWD).
Alphanate is prepared from pooled human plasma by cryoprecipitation of Factor VIII, fractional solubilization, and further purification employing heparin-coupled, cross-linked agarose which has an affinity to the heparin binding domain of VWF/FVIII:C complex. The product is treated with a mixture of tri-n-butyl phosphate (TNBP) and polysorbate 80 to reduce the risks of transmission of viral infection. In order to provide an additional safeguard against potential non-lipid enveloped viral contaminants, the product is also subjected to an 80°C heat treatment step for 72 hours. However, no procedure has been shown to be totally effective in removing viral infectivity from coagulation factor products.
Alphanate is labeled with the nominal antihemophilic factor potency (FVIII) in International Units (IU) per vial. Each vial of Alphanate also contains specific labeled amount of von Willebrand Factor Ristocetin Cofactor (VWF:RCo) activity expressed in IU. An IU is defined by the current international standard established by the World Health Organization. One IU of Factor VIII or one IU of VWF:RCo is approximately equal to the amount of Factor VIII or VWF:RCo in 1 mL of freshly-pooled human plasma.
Alphanate contains Albumin (Human) as a stabilizer, resulting in a final container concentrate with a specific activity of at least 5 FVIII:C IU/mg total protein. Prior to the addition of the Albumin (Human) stabilizer, the specific activity is significantly higher.
When reconstituted as directed, the composition of Alphanate is described in Table 1. (See Table 1.)

Click on icon to see table/diagram/image

Viral Reduction Capacity: The solvent detergent treatment process has been shown by Horowitz, et al., to provide a high level of viral inactivation without compromising protein structure and function. The susceptibility of human pathogenic viruses such as Human Immunodeficiency viruses (HIV), hepatitis viruses, as well as marker viruses such as Sindbis virus (SIN, a model for Hepatitis C virus) and Vesicular Stomatitis virus (VSV, a model for large, enveloped RNA virus), to inactivation by organic solvent detergent treatment has been discussed in the literature.
In vitro inactivation studies to evaluate the solvent detergent treatment (0.3% Tri-n-butyl Phosphate and 1.0% Polysorbate 80) step in the manufacture of Alphanate demonstrated a log inactivation of ≥11.1 for HIV-1, ≥6.1 for HIV-2, ≥4.1 for VSV and ≥4.7 for SIN. Since the number of virus particles inactivated by the process represents the maximum amount of virus added initially to the sample, these results indicate that all the virus added was killed to the assay limit of detection.
Additional steps in the manufacturing process of Alphanate were evaluated for virus elimination capability. The dry heat cycle of 80°C for 72 hours was shown to inactivate greater than 5.8 logs of Hepatitis A virus (HAV). Precipitation with 3.5% polyethylene glycol (PEG) and heparin-actigel-ALD chromatography are additional steps studied using Bovine Herpes virus (BHV, a model for Hepatitis B virus), Bovine Viral Diarrhea virus (BVD, a second model for Hepatitis C virus), human Poliovirus Sabin type 2 (POL, a model for Hepatitis A virus), Canine Parvovirus (CPV, a model for Parvovirus B19) and HIV-1.
Table 2 summarizes the reduction factors for each virus validation study performed for the manufacturing process of Alphanate. It must be stated that no treatment method has yet been shown capable of totally eliminating all potential infectious virus in preparations of coagulation factor concentrates. (See Table 2.)

Click on icon to see table/diagram/image