Protection of Biomanufacturing Processes from Virus Contamination
through Upstream Virus Filtration of Cell Culture Media
Abstract
Medical progress as enabled by early plasma products has also revealed
biological safety challenges. The combination of donor selection,
donation testing and virus reduction processes has effectively addressed
these concerns, and today medicinal plasma products feature significant
safety margins. The safety tripod concept has since been adapted to
biotechnology manufacturing platforms and has also ensured the safety of
these products. However, cell-based manufacturing processes have
occasionally been exposed to adventitious viruses, leading to
manufacturing interruptions and unstable supply situations. The rapid
progress of advanced therapy medicinal products (ATMPs) needs an
innovative approach to ensure the learnings from more traditional
biotechnology help to avoid any unwelcome reminder of the universal
presence of viruses. The introduction of up-stream virus clearance steps
has already been shown to be valuable for any products too complex for
down-stream interventions in the sense of both assuring product safety
and continuous supply. The gentlest method being virus filtration – the
development of which is presented here. The experiments investigated the
feasibility of implementing culture media virus filtration with respect
to their virus clearance capacities under extreme conditions such as
very high process feed loading (up to ~ 19,000 L/m
2), very long duration (up to 31 days), and multiple
process interruptions (up to 21, with cumulative interruptions of over
92 hours). Minute virus of mice (MMV) was used as a relevant target
virus, and in general, as a model small non-enveloped virus, as these
viruses are the main challenge for the investigated virus filters with a
stipulated pore-size of about 20 nm. It was found that certain filters
– especially of the newer 2 nd generation – are
capable of effective virus clearance despite the harsh regimen they were
subjected to. At the same time the investigation of biochemical
parameters for un-spiked control runs showed the filters to have no
measurable impact on the composition of the culture media. Based on
these findings, this technology seems to be quite feasible for large
volume pre-manufacturing process culture media preparations.