GMP production and testing of Xcellerated T Cells™ for the treatment of patients with CLL

Background Pre-clinical studies suggest Xcellerated T Cells(TM) 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(TM) 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(R) Bioreactor-based Xcellerate(TM) III Process using Xcyte(TM) Dynabeads(R) in a single custom 20-L Cellbag(TM) container was adapted, qualified and implemented for GMP operations. Results For n = 17 CLL patients, starting with approximately 1.34 x 10(9) CD3(+) T cells at 6.8 +/- 7.5% purity in the PBMC leukapheresis products, using the 10-L volume Wave(R) Bioreactor-based Xcellerate(TM) III Process, it was feasible to manufacture 137.0 +/- 34.3 x 10(9) Xcellerated T Cells(TM) 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(TM) produced from the Xcellerate(TM) 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-gamma and tumor necrosis factor (TNF)-alpha. 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(TM) for the treatment of CLL patients in clinical trials.