Suitability of transiently expressed antibodies for clinical studies: product quality consistency at different production scales

Abstract

Transgenic human monoclonal antibodies derived from humanized mice against different epitopes of the Middle East respiratory syndrome coronavirus (MERS-CoV), and chimeric llama-human bispecific heavy chain-only antibodies targeting the Rift Valley fever virus (RVFV), were produced using a CHO-based transient expression system. Two lead candidates were assessed for each model virus before selecting and progressing one lead molecule. MERS-7.7G6 was used as the model antibody to demonstrate batch-to-batch process consistency and, together with RVFV-107-104, were scaled up to 200 L. Consistent expression titers were obtained in different batches at a 5 L scale for MERS-7.7G6. Although lower expression levels were observed for MERS-7.7G6 and RVFV-107-104 during scale up to 200 L, product quality attributes were consistent at different scales and in different batches. In addition to this, peptide mapping data suggested no detectable sequence variants for any of these candidates. Functional assays demonstrated comparable neutralizing activity for MERS-7.7G6 and RVFV-107-104 generated at different production scales. Similarly, MERS-7.7G6 batches generated at different scales were shown to provide comparable protection in mouse models. Our study demonstrates that a CHO-based transient expression process is capable of generating consistent product quality at different production scales and thereby supports the potential of using transient gene expression to accelerate the manufacturing of early clinical material.

Effects of the COVID-19 pandemic: new approaches for accelerated delivery of gene to first-in-human CMC data for recombinant proteins

“…For developing antibodies against SARS-CoV-2 in a timely manner, transient expression was used to support process development and even contemplated for supplying preclinical studies. 15 , 101 , 102 …”

A CHO stable pool production platform for rapid clinical development of trimeric SARS‐CoV‐2 spike subunit vaccine antigens

“…However, a common feature has been the mandatory use of stable clonal cell lines for both clinical development and manufacturing, a result of several factors including longstanding regulatory guidelines (Stuible et al, 2018). With recent and significant improvements in performance, alternative non‐clonal platforms, including stably transfected CHO pools and transient gene expression, are now capable of producing recombinant proteins more rapidly and cost‐effectively with yields and quality similar to clonal cell lines (Fan et al, 2017; Hu et al, 2017; Munro et al, 2017; Rajendra et al, 2017; Rodriguez‐Conde et al, 2022; Scarcelli et al, 2017; Wright et al, 2017; Ye et al, 2010). Such methods may now be in a unique position to facilitate rapid clinical evaluation of novel, life‐saving protein‐based biologics.…”

Exploring Parametric and Mechanistic Differences between Expi293FTM and ExpiCHO-STM Cells for Transient Antibody Production Optimization

“…Through cell line engineering, vector engineering, and process engineering, antibody titers greater than 1 g/L produced transiently by HEK293 cells on a large scale have been reported [ 7 , 8 ]. Similarly, despite the initial modest expression yields [ 9 , 10 ], the transient CHO systems also reach the expression titer range of 1–3 g/L for a number of antibodies [ 11 , 12 , 13 , 14 , 15 , 16 , 17 ]. However, TGE technologies still face significant challenges.…”