Techno-Economic Assessment of Cell-Free Synthesis of Monoclonal Antibodies Using CHO Cell Extracts

Nilay Shah,Cleo Kontoravdi,Vaishali Thaore,Dimitrios Tsourapas

doi:10.3390/pr8040454

Abstract

Cell-free protein synthesis (CFPS) is an emerging tool for the rapid production of difficult-to-express proteins as well as for identifying protein synthesis bottlenecks. In CFPS, the biotic phase is substituted by extracts of living cells devoid of any of their own genetic material. The main advantage is that these systems delineate cell growth from recombinant protein production, enabling the expression of targets that would otherwise place too big a burden on living cells. We have conducted a techno-economic analysis of a CFPS system to produce monoclonal antibodies (mAbs) using extracts of Chinese hamster ovary (CHO) cells. We compare the performance of the CFPS system with two alternative production strategies: stable and transient gene expression in CHO cells. Our assessment shows that the viability of CFPS for mAb production requires a significant increase in the product yield and the recycling of high-cost components such as DNA. Nevertheless, CFPS shows significant promise for personalized medicine applications, providing a platform for on-demand production and simplified supply chains.

Highlights

Mammalian cells have been the dominant expression system for various types of recombinant proteins including monoclonal antibodies, fusion proteins, and other high value proteins with complex folding and post-translational modification requirements [1,2,3]
stable gene expression (SGE) involves the stable integration of the gene encoding for the recombinant protein in the DNA of the host cell, in this case Chinese hamster ovary (CHO) cells, by the application of a selective pressure, whereas in transient gene expression (TGE) the same gene is temporarily expressed for rapid protein production
The associated capital and operating costs are summarized in Upstream Processing (USP) and a 75% monoclonal antibodies (mAbs) recovery in Downstream Processing (DSP), the total capital investment for SGE was estimated to be $47.6 M, which involves direct fixed capital ($45 M), start-up and validation costs ($2.2 M), and working capital

Summary

Introduction

Mammalian cells have been the dominant expression system for various types of recombinant proteins including monoclonal antibodies (mAbs), fusion proteins, and other high value proteins with complex folding and post-translational modification requirements [1,2,3]. The large-scale production of mAbs is currently achieved by stable gene expression (SGE) of recombinant DNA, whereas transient gene expression (TGE) is used to produce material for early-stage pre-clinical studies [6,7,8]. HEK-293 cells in 14 day-cultures [8], milligram quantities of recombinant mAb have mostly been reported with CHO cells [9,10]. This contrasts with SGE, in which a 1–3 g mAb/L yield can be readily achieved [3,5], increasing to 5–10 g mAb/L in optimized fed-batch and perfusion systems [11,12]

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Discussion

Conclusion