Why bioreactors? Dr Kim Warren, Head of Development Services, Cell Therapy at Lonza, continued the afternoon session on Scalable Manufacture and Distribution by asking this question. In cell therapy applications, doses per patient can be very high, with certain indications requiring millions of cells. At the beginning of her talk, Dr Warren suggested that we should be aiming for a lot size of 1 trillion cells. Commonly used multi-layer expansion systems can only produce several billion cells. Dr Warren’s talk centred around a cost comparison of expanding hMSCs in a 200L bioreactor versus a 40-layer Cell Factory with Automatic Cell Factory Manipulator (CF-40). At Lonza, hMSCs are currently being grown in up to 50L bioreactors. Dr Warren said that cost would be a rate limiting step, as any system larger than 200L would have a cost per run that is just too high.
All aspects of the process were compared, from facility size to labour requirements and Cost of Goods (COGs). Whereas a bioreactor method would require just 600 sq. ft. for 5 parallel campaigns, a CF-40 setup would need almost double that area for just 3 campaigns. When looking further at the campaigns, 80 cumulative campaigns could be completed by the bioreactor setup in less than 30 weeks, compared to just less than 60 weeks for the CF-40. This also had an effect on labour, which is significant considering Dr Warren’s model showed labour to be the largest component of the bioreactor system’s COGs. In the CF-40, suite fees and equipment usage was the largest contributor to the COGs.
The model showed an impressive cost saving of 53% on COGs when using bioreactors to expand hMSCs. But costs can be reduced even further by improving cell yield in the bioreactors. Dr Warren has shown us that bioreactor systems in this case are indeed faster and cheaper, but questioned whether that automatically meant that they were better. She followed by highlighting the need for good cell characterisation, and to ensure that cells obtained by bioreactor expansion are comparable to those expanded on multi-layer systems. She closed proposing that we could perhaps start to use bioreactors for cell expansion from the very beginning of product development.
Nathalie Moens for Total BioPharma at the World Stem Cell and Regenerative Medicine Congress
Nathalie Moens is a Postdoctoral Research Associate at the Centre for Stem Cells and Regenerative Medicine, King’s College London