Process development for production of non-originator NISTmAb from CHO and NS0 cell lines

Cell lines that produce non-originator versions of the National Institute of Standards and Technology (NIST) monoclonal antibody reference material 8671 (NISTmAb) are invaluable to the biopharmaceutical industry because, unlike typical commercial cell lines, they can be used on a collaborative and noncompetitive basis for bioprocess development. NIST has generated NS0 clones, NISTCHO research-grade test material 10197 and reference material 8675 NISTCHO to fill this need. We set out to optimize seed train procedures, media and feeding strategies, and stirred tank and rocking bioreactor processes to facilitate our studies on the effects of cell substrate and bioreactor process parameters on non-originator NISTmAb quality attributes. For two NS0 clones and NISTCHO, we improved the baseline methods for seed train culture and demonstrated the critical roles of agitation and gassing strategies for stirred-tank bioreactor operations. For NISTCHO we also tested fed-batch and perfusion processes in rocking bioreactors, identifying several critical process parameters and in-process controls. In this work, for the NIST NS0-59 and NS0-66 clones, we demonstrated that shake flask geometry was critical for culturing a highly viable seed train with a high growth rate and exhibited impacts of feeds, agitation, and gassing during initial bioreactor process development. We identified agitation rates and gassing strategy as critical process parameters for NISTCHO stirred-tank bioreactor operations and established processes for fed-batch and perfusion rocking bioreactor operations. We anticipate this work to benefit the growing number of researchers employing non-originator NISTmAb-expressing cell lines to support precompetitive innovation in biomanufacturing.