Abstract
Background Pre-clinical studies suggest Xcellerated T Cells™ have the potential to produce a potent anti-tumor effect, restore broad immune function and reduce the risk of infectious complications in patients with CLL. Unlike other cancer settings, T cells constitute only a small fraction of CLL patients’ PBMC. To generate large numbers of Xcellerated T Cells™ of high purity from CLL patients’ PBMC, a reproducible, streamlined and cost-effective good manufacturing process (GMP) is required.
Methods The 10-L volume Wave® Bioreactor-based Xcellerate™ III Process using Xcyte™ Dynabeads® in a single custom 20-L Cellbag™ container was adapted, qualified and implemented for GMP operations.
Results For n=17 CLL patients, starting with approximately 1.34×109 CD3+ T cells at 6.8±7.5% purity in the PBMC leukapheresis products, using the 10-L volume Wave® Bioreactor-based Xcellerate™ III Process, it was feasible to manufacture 137.0±34.3×109 Xcellerated T Cells™ at 98.5±1.0% CD3+ T-cell purity. An average 400-fold clearance of malignant B cells was documented during the manufacturing process. The Xcellerated T Cells™ produced from the Xcellerate™ III Process exhibited high in vitro biologic activity and have their T-cell receptor repertoire restored to a normal diversity. In-process T-cell activation was reproducibly robust, as measured by increase in cell size, up-regulation of CD25 and CD154 expression and the secretion of IL-2, IFN-γ and tumor necrosis factor (TNF)-α.
Discussion A low-volume, high-yield bioreactor-based process has been developed, qualified and implemented for the reproducible, GMP manufacture of high purity, biologically active Xcellerated T Cells™ for the treatment of CLL patients in clinical trials.