CLEARANCE OF MURINE LEUKEMIA-VIRUS FROM MONOCLONAL-ANTIBODY SOLUTIONSBY A HYDROPHILIC PVDF MICROPOROUS MEMBRANE-FILTER

Continuous cell lines (used in the manufacture of monoclonal antibodie s and other therapeutic proteins) may harbour retroviral particles; ne vertheless,they are deemed acceptable if the production system is vali dated for clearance of these contaminants. As part of a campaign to ev aluate and validate appropriate virus removal methodologies for monocl onal immunoglobulin G (IgG)products, studies were undertaken with a hy drophilic polyvinylidene fluoride (PVDF) microporous membrane-the Ulti po(R) VF grade DV50 virus removal membrane. Testing conducted with mur ine leukaemia virus, a specific model virus used in viral validation s tudies to document removal of retroviruses, demonstrated a greater tha n 7 log clearance by the Ultipor(R) VF grade DV50 membrane. Filter abi lity testing established the feasibility of positioning the filter at either of two different stages during manufacture. The results present ed in this study demonstrate that membrane filtration through the Ulti por VF grade DV50 virus removal filter can constitute part of the puri fication regimen to effect removal of endogenous retrovirus-like conta minants from monoclonal IgG products. (C) 1998 The International Assoc iation of Biological Standardization.