By integrating continuous cell cultures with continuous purification
methods, process yields and product quality attributes were improved
over the last 10 years for recombinant protein production. However, for
the production of viral vectors such as Modified Vaccinia virus Ankara
(MVA), no such studies have been reported although there is an
increasing need to meet the requirements for a rising number of clinical
trials against infectious or neoplastic diseases. Here, we present for
the first time a scalable suspension cell (AGE1.CR.pIX cells)
culture-based perfusion process in bioreactors integrating continuous
virus harvesting through an acoustic settler with semi-continuous
chromatographic purification. This allowed to obtain purified MVA
particles with a space-time yield >600% higher for the
integrated perfusion process (1.05 x 1011 TCID50/Lbioreactor/day)
compared to the integrated batch process. Without further optimization,
purification by membrane-based steric exclusion chromatography resulted
in an overall product recovery of 50.5%. To decrease the level of host
cell DNA prior to chromatography, a novel inline continuous DNA
digestion step was integrated into the process train. A detailed cost
analysis comparing integrated production in batch versus production in
perfusion mode showed that the cost per dose for MVA was reduced by
nearly one third using this intensified small-scale process.
A high cell density perfusion process for Modified Vaccinia virus Ankara production: Process integration with inline DNA digestion and cost analysis
