Aim: To perform a validation study of the production process of a human high purity FVIII concentrate, obtained by affinity chromatography and treated with solvent-detergent and 80 degrees C, 72- hour dry heating in the final vial, in order to demonstrate its viral safety.
Material and methods: The ability to inactivate or eliminate viruses was studied in the steps of PEG precipitation, solvent-detergent treatment (6 h 25 degrees C), affinity chromatography and lyophilization plus heating 80 degrees C for 72 h. HIV and models for hepatitis A, B and C, as well as a model for parvovirus B-19 were employed. The experiments were carried out by spiking the samples at each step with 10% of their volume with the highest titer available virus culture. The samples were processed under validated conditions (mimicking the industrial process) and the residual infectivity was determined (as well as p24 antigen and reverse transcriptase for HIV at the solvent-detergent step).
Results: No residual infectivity could be detected for enveloped viruses (HIV and models for hepatitis B and C) after the first minutes of solvent-detergent treatment, which lasts 6 hours. Lyophilization followed by heating 80 degrees C for 72 hours caused complete disappearance of infectivity for the models of hepatitis A and C, before 24 hours of a treatment which lasts 72. Furthermore, lyophilization plus heating reduced infectivity for the models of hepatitis B and parvovirus B-19 by 3.4 and 4.1 logs, respectively. The affinity chromatography reduced infectivity by 7.6 logs for the model of hepatitis B and 2 logs for HIV. PEG precipitation also reduced the infectivity by 3.3 logs for the model of hepatitis A and by 1.2 logs for the model of parvovirus B-19. Taking the process as whole, the study showed cumulative reduction values between 5.3 and > 19 logs of the analyzed viruses. 25 million FVIII units have been transfused so far as FANHDI, with no seroconversion detected. Furthermore, no increase in FVIII inhibitor frequency has been described.
Conclusion: The FVIII concentrate described shows outstanding viral safety characteristics. These data, together with the preliminary clinical experience after one year usage of the product, indicate that FANHDI is a suitable preparation for haemophilia A treatment.