22, 23 However, this study demonstrates the eligibility of the TCT process for the manufacture of anti-CD20 CAR T cells, whereby starting material is also obtained from heavily pretreated patient-derived material (PM). This system has already been demonstrated as a current Good Manufacturing Practice (cGMP)-compliant protocol for the generation of engineered T cells on a clinical scale, starting from LP from healthy donors (HD). 21 This study sought to develop, optimize, and verify the fully closed, automated T cell transduction (TCT) process on the CliniMACS Prodigy™ platform to prepare genetically engineered T cells in <2 weeks under closed conditions, starting from leukapheresis (LP), buffy coat (BC), or whole blood (WB). Current processes face challenges toward meeting potentially large demand upon growing success. It requires skilled operators, as well as a dedicated infrastructure. The authors therefore set out to develop anti-CD20 CAR T cells for such indications and generated a second-generation CAR construct comprising an extracellular single-chain variable fragment (scFv) directed against CD20 and linked to intracellular signaling domains (4-1BB_CD3ζ). Due to the outstanding potency of engineered T cells, using anti-CD20 CAR-expressing T cells instead of rituximab, it is likely to improve further the clinical impact for the treatment of metastatic melanoma and B cell malignancies. #Texmacs gmp medium trial16–18 Interestingly, in a case study, rituximab also induced established metastatic melanoma regression in patients, 19, 20 leading to a clinical Phase II trial ( identifier NCT01376713). 14, 15 In line with this observation, rituximab, an anti-CD20 specific monoclonal antibody, has a major clinical impact on lymphomas, including diffuse large B cell lymphoma (DLBCL), follicular lymphoma, and chronic lymphocytic leukemia (CLL). 12ĬD20 is stably expressed at a high level on >90% of patients with B cell lymphomas, 13 as well as on a minor subset of cancer-sustaining melanoma cells. 11 Such relapses can be observed in approximately 30% of relapsed/refractory B cell acute lymphoblastic leukemia (ALL) patients receiving CD19-directed therapies and are always associated with a very poor prognosis. 5–10 However, despite the promising scientific and medical successes of the anti-CD19 CAR T cells, a significant number of patients still do not respond to this cell-based therapy due to a poor T cell persistency, insufficient functionality, or the loss of CD19. 1–4 In particular, engineered T cells expressing the anti-CD19 chimeric antigen receptor (CAR) have shown remarkable and durable responses in several clinical trials against leukemia and lymphoma. M odified T cells are currently one of the most promising therapeutic approaches for the treatment of advanced hematopoietic malignancies, solid cancer, and infectious diseases, thus supporting the importance and potential of adoptive cellular therapy (ACT). In summary, the automated T cell transduction process meets the requirements for clinical manufacturing that the authors intend to use in two separate clinical trials for the treatment of melanoma and B cell lymphoma. Potent antitumor reactivity of the produced anti-CD20 CAR T cells was shown in vitro as well as in vivo. Interestingly, the formulated product obtained with PM was comparable to that of HD with respect to cell composition, phenotype, and function, even though the starting material differed significantly. Independent of the starting material, operator, or device, the process consistently yielded a therapeutic dose of highly viable CAR T cells. Starting from healthy donor (HD) or lymphoma or melanoma patient material (PM), the robustness and reproducibility of the manufacturing of anti-CD20 specific CAR T cells were verified. Upon installation of the closed, single-use tubing set on the CliniMACS Prodigy™, sterile welding of the starting cell product, and sterile connection of the required reagents, T cells are magnetically enriched, stimulated, transduced using lentiviral vectors, expanded, and formulated. An automated current Good Manufacturing Practice–compliant process has therefore been developed for the generation of gene-engineered T cells. Furthermore, extensive training of personnel is required to avoid operator variations. Conventional protocols comprise many open handling steps, are labor intensive, and are difficult to upscale for large numbers of patients. The clinical success of gene-engineered T cells expressing a chimeric antigen receptor (CAR), as manifested in several clinical trials for the treatment of B cell malignancies, warrants the development of a simple and robust manufacturing procedure capable of reducing to a minimum the challenges associated with its complexity.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |