The use of a transient transfected expression system to deliver high quality bispecific T-cell engager drug product, NVG-111, to the clinic for a fraction of the cost and time associated with the development and use of a producer cell line.

Abstract

e14506 Background: Bispecific antibodies provide an opportunity to treat a diverse range of disorders because of their ability to simultaneously attenuate several different pathways precisely and effectively, thus overcoming many of the limitations of monoclonal antibodies. The adaptability of bispecifics has facilitated the generation of compelling preclinical data covering a range of malignant and non-malignant disorders. Proof-of-concept early phase clinical trials with bispecific antibodies, including bispecific T-cell engagers (TCE) have been hindered by manufacturing challenges, including a heavy burden in terms of time, quality and costs associated with generating a stable producer cell line. We took a more agile approach, using transient transfection to manufacture a ROR1×CD3 bispecific TCE drug product (DP [NVG-111]) for a first in human, Phase I/II clinical trial. Methods: A HEK293T cell line was expanded into 10-layer cell factories. The cells were transfected with a ROR1xCD3 scFv bispecific antibody (NVG-111) plasmid and incubated. Post incubation, the supernatant containing NVG-111 was clarified by filtration and subjected to solvent/detergent viral inactivation. This was followed by a concentration/buffer exchange step and subsequent DNA reduction using an endonuclease. NVG-111 was captured using a bind/elute Protein A column and the eluate polished on a multimodal anion exchange column in flow through mode to remove residual impurities. The eluate was formulated and concentrated to the target protein concentration, viral and sterile filtered and QC tested. The bulk drug substance was 0.2 µm filtered into Din 2R vials and the DP stored at ≤-65°C pending release. Results: The transient transfection approach resulted in the rapid tech transfer and GMP manufacture of clinical NVG-111 DP. Two batches of DP were manufactured producing 1,971 vials of NVG-111, sufficient to support the Phase I/II clinical trial in patients with advanced Chronic Lymphocytic Leukaemia and Mantle Cell Lymphoma (Clinical Trial.gov NCT04763083). Both batches met the approved specifications for identity, potency, purity/impurities, strength and safety. The exercise took less than 7 months from contract signature to DP in the freezer and cost ̃50% of the more traditional producer cell line approach. Conclusions: We established a novel GMP process in 7 months, using transient transfection to manufacture NVG-111 for Phase I/II trials. The process costed less than the more conventional manufacturing approach of using a producer cell line. The strategy offers a rapid, and very efficient way of reaching a first in human study without a trade-off between time, quality and cost.