Multiple clinical studies demonstrated that adaptive immunotherapy using redirected T cells against advanced cancer has led to promising results with improved survival of the patients. The continuously increasing interest in those advanced Gene Therapy Medicinal Products (GTMPs) leads to a challenge on the manufacturing side regarding automation, process robustness and cell storage. Therefore, our study addresses the proof of principle in clinical-scale selection, stimulation, transduction and expansion of T cells using the automated closed CliniMACS® Prodigy system. Naïve and central memory T cells from apheresis products were first immunomagnetically enriched using anti-CD62L magnetic beads and further processed freshly (n=3) or split for cryopreservation and processed after thawing (n=1). Starting with 0.5×108 purified CD3+ T cells, 3 mock runs and one run including transduction with GFP containing vector resulted in a median final cell product of 16×108 T cells (32-fold expansion) up to harvesting after two weeks. Expression of CD62L was downregulated on T cells after thawing which led to the decision to purify CD62L+CD3+ T cells freshly with cryopreservation thereafter. Most important in the split product a very similar expansion curve was reached comparing the overall freshly CD62L selected cells with those after thawing, which could be demonstrated in the T cell subpopulations as well by showing a nearly identical conversion of the CD4/CD8 ratio. In the GFP run the transduction efficacy was 83%. In-process control also demonstrated sufficient glucose levels during automated feeding and medium removal. The process robustness and the constant quality of the final product in a closed and automated system give rise to improve harmonized manufacturing protocols for engineered T cells in future gene therapy studies.
Automated enrichment, transduction and expansion of clinical-scale CD62L+ T cells for manufacturing of GTMPs.