Multiple studies have found continuous bioprocessing reduces commercial cost of goods (COG) by between 10% and 30%, largely because the approach enables smaller manufacturing trains and the implementation of single-use technologies at those reduced scales.
However, the effect of continuous bioprocessing on process development, which with clinical manufacturing is estimated to account for 17% of all R&D costs, is less clear. Higher process development costs could exceed subsequent commercial savings.
Writing in the journal Biotechnology and Bioengineering in April, researchers from University College London and the Centre for Process Innovation presented an analysis intended to show whether end-to-end continuous bioprocessing is cost effective when spending on process development and commercial manufacturing is considered.
The analysis predicted single-use continuous facilities will typically have a cost advantage over stainless steel batch plants. At facilities with annual demands of 100kg to 500kg, continuous bioprocessing has a 35% advantage, although the difference in indirect costs falls to zero at larger sites that need four or more parallel trains to handle 3,000kg a year or more.
Earlier studies suggested the analysis would find continuous bioprocessing has a cost advantage in commercial scales. The bigger question was whether the advantage would be large enough to offset any additional process development costs.
The analysis found large companies, which have multiple drug candidates and therefore spend more on chemistry, manufacturing and controls (CMC), incur a two-fold increase in process development costs when using continuous bioprocessing. That additional spending outweighs the 20% saved on manufacturing, leading continuous bioprocessing to cost large companies around $40m more.
At smaller companies, which spend less on CMC, the COG savings outweigh the additional process development costs associated with continuous bioprocessing. Yet, even at those small companies, single-use batch or single-use hybrid offer savings over end-to-end continuous bioprocessing.
According to the analysis, the value of continuous bioprocessing only becomes clear once the project lifecycle cost is considered. Over 10 years of commercial manufacturing, the cost benefits of the continuous model add up.
“Although CMC costs with continuous processes are likely to be higher than batch processes when considered as a new technology, it is possible for continuous processes to be as or more competitive than the best batch process when the total lifecycle out-of-pocket costs are considered,” the authors of the study concluded.
At 200kg a year, a scale at which continuous has pronounced COG benefits over batch, the approach offers 18% to 34% lower costs than stainless steel and is competitive with single-use batch. There is scope for the benefits of continuous bioprocessing to increase if process development, scaling and optimisation are simplified in the future.