High Capacity Immunomagnetic Isolation of Apheresis Samples in an Automated Closed System

Abstract

Abstract Cell therapy development, including Chimeric antigen receptor (CAR)-T cells, involves many steps and requires processing on average 3 billion white blood cells or more. Automated large scale immunomagnetic cell isolation with high efficiency and throughput in a closed system is desired to enrich T cells from apheresis products. Current automated, high capacity methods are time consuming, high cost, low yield and can potentially influence the physiology of the target cells. We have developed an automated closed magnetic separation platform, MARS® Bar to address these problems. This platform uses three uniquely designed magnetic separation modules and each magnetic module can perform positive or negative selection of target cells in a fluidic chamber at high flow rate (1mL/min per module). On this platform we have developed cell isolation reagents and program with minimal cell preparation. In the pilot study, we isolated 116 million CD3+ T cells from 267million CD45+ cells in a single LSR chamber on a single MARS® module. The entire automated process took less than 15 minutes to complete and resulted in > 95% purity and > 96% recovery of CD3+ T cells. The isolated cells were then activated and expanded, with results showing high proliferation and the dominant population being central memory T cells. The unique MARS® Bar matrix-free design has unlimited capacity because of the automated release of positively captured cells and very low carry-over. This was validated by processing greater than 3 billion leukocytes at 20 million cells per mL within the three modules in parallel and intermittent release of captured cells for collection. The MARS® Bar can be easily integrated into standard T cell production workflow.