Optimizing CAR-T Cell Manufacturing Processes during Pivotal Clinical Trials.

Tisagenlecleucel is a CD19-specific chimeric antigen receptor (CAR)-T cell therapy approved for patients aged ≤25 years with relapsed or refractory B cell precursor acute lymphoblastic leukemia (B-ALL) and adults with relapsed or refractory diffuse large B cell lymphoma (DLBCL). The initial tisagenlecleucel manufacturing process technology was developed at an academic center and was subsequently transferred, optimized, validated, and scaled out to supply large global trials before commercialization. Tisagenlecleucel manufactured in two centralized facilities has been successfully used in global multicenter trials for B-ALL and DLBCL (>50 clinical centers in 12 countries). In this paper, we describe some of the continuous process improvements made to tisagenlecleucel manufacturing over time to meet global demand while maintaining and improving product quality. During early tisagenlecleucel clinical trials, process enhancements were made to address logistical challenges related to manufacturing for multicenter trials and to accommodate the variability observed in patient starting cellular material. These enhancements resulted in improvements in manufacturing capacity, process robustness, manufacturing success rates, and product quality, and reductions in throughput time. In summary, through continuous evaluation and improvements based on experience during global trials, a consistent and robust commercial manufacturing process for tisagenlecleucel has been developed, leading to improvements in manufacturing success when compared to the initial processes.

Autologous cryopreserved leukapheresis cellular material for chimeric antigen receptor-T cell manufacture.

Tisagenlecleucel, a CD19-specific autologous chimeric antigen receptor (CAR)-T cell therapy, is efficacious for the treatment of relapsed/refractory B-cell precursor acute lymphoblastic leukemia and diffuse large B-cell lymphoma. The tisagenlecleucel manufacturing process was initially developed in an academic setting and subsequently transferred to industry for qualification, validation and scaling up for global clinical trials and commercial distribution. Use of fresh leukapheresis material was recognized early on in the transfer process as a challenge with regard to establishing a global supply chain. To maximize manufacturing success rates and to overcome logistical challenges, cryopreservation was adapted into the Novartis manufacturing process from the beginning of clinical trials. Tisagenlecleucel manufactured in centralized facilities with cryopreserved leukapheresis material has been used successfully in global clinical trials at more than 50 clinical centers in 12 countries. Cryopreservation provides flexibility in scheduling leukapheresis when the patient's health is optimal to provide T cells; it also provides protection from external factors, such as shipping delays, and removes manufacturing time constraints. Several studies were performed to establish comparability of fresh versus cryopreserved leukapheresis material, to evaluate and optimize the cryopreservation process, to determine the optimal temperature and maximum hold time prior to cryopreservation and to determine the optimal temperature range for shipment and storage. Using the current validated industry manufacturing process, high success rates were achieved with regard to manufacturing tisagenlecleucel batches that met specifications and were released to patients. Consistent product quality and positive clinical outcomes support the use of cryopreserved non-mobilized peripheral mononuclear blood cells collected using leukapheresis for CAR-T cell manufacturing.