Rapid manufacture of low-seed CAR-T cells in a GMP-grade hollow-fiber bioreactor platform

Abstract

Both quality of product and rapidity of manufacture are critical parameters if ex vivo manufacturing of autologous chimeric antigen receptor T cell (CAR-T) therapies is to reach its full potential. The Quantum Flex™ Cell Expansion System from Terumo Blood and Cell Technologies (Terumo BCT), a hollow-fiber bioreactor platform, is one of several cell expansion systems available to cell and gene therapy manufacturers to generate such cells in a GMP-compliant manner. In this study, the dynamic range of the Quantum Flex platform to expand CD19 CAR-T cells from variable quantities of starting material was investigated. Reflecting the industry's utilization of contract development manufacturing organizations (CDMOs) for accelerating clinical timelines, Terumo Blood and Cell Technologies performed a technology transfer of application protocols for study execution. Four different amounts starting material (1, 3, 6, and 15 million cells) were expanded on Quantum Flex, using a unique donor's cells for each run. In this study, CAR-T cells were created using commercially obtained T cells and an anti-CD19 CAR-T lentiviral construct. The resultant heterogenous cell populations were expanded for 7 days in the functionally closed bioreactor platform. Expansion kinetics for all 4 starting material amounts were remarkedly similar, resulting in a 150- to 200-fold increase in cell numbers. This allowed for a study maximum of 2.6 billion cells from loading 15 million cells. Viability remained high throughout the expansion process with > 93% for all 4 donors at harvest. To complete the manufacturing cycle, the automated and functionally closed Finia™ Fill and Finish System (Terumo Blood and Cell Technologies, Lakewood, CO) was used to formulate the cells for cryopreservation. Post-procedure analysis for potency and cytotoxicity demonstrated the production of efficacious cells. With this range of starting numbers, the platform is relevant to adult, pediatric, and compassionate CAR-T expansion dosing. Today, several platforms are available to achieve sufficient cell yields for therapeutic applications of CAR-T, and awareness of the capabilities, pros, and cons of each platform is critical to drive progress.