Viability of Chimeric Antigen Receptor T Cell Therapy in Latin America

Introduction: Treatment of diffuse large B cell lymphoma (DLBCL) may be a challenge for Latin American countries. Thus, novel strategies to reduce the economic burden of oncological care are necessary. In Brazil, the DLBCL annual incidence is approximately 6.000 cases, among which 30% will relapse or become refractory (R/R). In this scenario, the limited access to the new therapies reinforce the need to develop new local technologies and improve research initiatives. Here we report the development and clinical application of a Brazilian platform to manufacture genetically modified T-cells to treat patients with R/R leukemia and lymphomas, which may also help reverse the poor prognosis of these patients in low and middle-income countries. Patients and Methods: All patients were referred to our center to consider compassionate use of anti-CD19 CAR-T cell therapy. The treatment was authorized by the local medical ethical committee. Once patients were deemed to be eligible for CAR-T, they were scheduled for lymphopheresis and the cells were processed and cryopreserved. During the manufacturing process and after completion of lymphophersis, all three patients received bridging therapy. Prior to infusion of CAR-T, patients were given lymphodepletion chemotherapy with cyclophosphamide and fludarabine for 3 days. Patients were monitored daily for the occurrence of cytokine release syndrome (CRS) and immune effector cell associated neurotoxicity syndrome (ICANS), which were graduated according to the criteria of the American Society for Transplantation and Cellular Therapy. These treatments were only available because we developed a Brazilian platform to manufacture genetically modified T-cells. Firstly, we developed and validated in vitro and in vivo anti-CD19 CAR T cell expression, expansion, and cytotoxicity. Secondly, in-house lentiviral good-manufacturing practice (GMP) protocols were established for clinical purposes. Thirdly, we upscaled the manufacturing process into the GMP facility originally developed for MSCs and adapted it to genetically modified T-cells. Finally, in-house procedures to deliver anti-CD19 CAR T cells for clinical use were established according to the Brazilian Health Regulatory Agency (ANVISA) policies. Once these steps were implemented, we were able to treat the first three patients of a patient with CAR-T cells produced in Latin America. Results: Two patients presented CAR-T cell expansion after the procedure (Figure 1). Within thirty days after the infusion one patient achieved complete response, one had partial response and one was not evaluated (Table 1). All patients had CRS and only one had ICANS. Two patients died, one from infection and other from intracranial hemorrhage due to domestic accident, --- and --- days after CAR-T cell infusion, respectively. Discussion: At least two of the reported patients presented improvement of their disease. The other one died before the expected response could have been evaluated. None of the patients died from complications related to manufacturing or infusion procedures, highlighting an acceptable safety profile of the platform. Although these are preliminary results, the CAR-T cell expansion profile, presence of systemic inflammatory response and lack of early disease progression suggest the treatment effectiveness. Conclusion: Apart from all the scientific challenges, this experience highlights the feasibility to implement a viable and efficient CAR-T platform in middle-income countries. Besides, implementation of advanced cellular therapy can also contribute to enhancing the quality of other cellular therapies.

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Figure 1

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