Clearance of murine leukaemia virus from monoclonal antibody solutions by a hydrophilic PVDF microporous membrane filter

Continuous cell lines (used in the manufacture of monoclonal antibodies and other therapeutic proteins) may harbour retroviral particles; nevertheless,they are deemed acceptable if the production system is validated for clearance of these contaminants. As part of a campaign to evaluate and validate appropriate virus removal methodologies for monoclonal immunoglobulin G (IgG)products, studies were undertaken with a hydrophilic polyvinylidene fluoride (PVDF) microporous membrane-the Ultipo(R) VF grade DV50 virus removal membrane. Testing conducted with murine leukaemia virus, a specific model virus used in viral validation studies to document removal of retroviruses, demonstrated a greater than 7 log clearance by the Ultipor(R) VF grade DV50 membrane. Filter ability testing established the feasibility of positioning the filter at either of two different stages during manufacture. The results presented in this study demonstrate that membrane filtration through the Ultipor VF grade DV50 virus removal filter can constitute part of the purification regimen to effect removal of endogenous retrovirus-like contaminants from monoclonal IgG products. (C) 1998 The International Association of Biological Standardization.