Towards automated manufacturing of clinical scale gene-modified T cells

Abstract

Adoptive immunotherapy using gene-modified T cells redirected against cancer has proven clinical efficacy and tremendous potential. However, such individualized therapy is complex and the cellmanufacturing process requires extensive training of personnel as well as a dedicated infrastructure, which restricts these clinical procedures to very few institutions worldwide. The current protocol for genetic modification of human T cells with viral vectors includes the preparation of human blood cells by density gradient centrifugation, the activation of enriched T cells, the genetic modification of the activated T cells with viral vectors and the expansion of the genetically-modified T cells. Such a process comprises many (open) handling steps, is labor intensive and is not adapted to treat large numbers of patients or for commercial manufacturing. In order to face these challenges, novel technologies are required. Using the CliniMACS Prodigy® platform, we show that automated gene-modification of T cells is possible in a closed single-use tubing set. After sterile welding of a buffy coat to the tubing set, T cells were automatically labeled with CD4 and CD8 MicroBeads and magnetically enriched. The CD4+ and CD8+ T cells were then automatically activated with the MACS GMP CD3/CD28 TransAct Kit that resulted in high frequencies of activated T cells (CD25+ and CD69+) on day 2. Automated lentiviral vector transduction and subsequent T cell expansion were also carried out with minimal user intervention. Enriched T cells were cultured in TexMACS GMP Medium supplemented with recombinant human IL-2. Clinically relevant numbers of gene-modified T cells were generated after 10-14 days. The flexibility and ease of use associated with this device and the developed process for clinical scale production of engineered T cells will enable treatment of large patient groups and make economic commercial-scale manufacturing possible.