RESUMEN
PURPOSE: CAR therapy targeting BCMA is under investigation as treatment for multiple myeloma. However, given the lack of plateau in most studies, pursuing more effective alternatives is imperative. We present the preclinical and clinical validation of a new optimized anti-BCMA CAR (CARTemis-1). In addition, we explored how the manufacturing process could impact CAR-T cell product quality and fitness. METHODS: CARTemis-1 optimizations were evaluated at the preclinical level both, in vitro and in vivo. CARTemis-1 generation was validated under GMP conditions, studying the dynamics of the immunophenotype from leukapheresis to final product. Here, we studied the impact of the manufacturing process on CAR-T cells to define optimal cell culture protocol and expansion time to increase product fitness. RESULTS: Two different versions of CARTemis-1 with different spacers were compared. The longer version showed increased cytotoxicity. The incorporation of the safety-gene EGFRt into the CARTemis-1 structure can be used as a monitoring marker. CARTemis-1 showed no inhibition by soluble BCMA and presents potent antitumor effects both in vitro and in vivo. Expansion with IL-2 or IL-7/IL-15 was compared, revealing greater proliferation, less differentiation, and less exhaustion with IL-7/IL-15. Three consecutive batches of CARTemis-1 were produced under GMP guidelines meeting all the required specifications. CARTemis-1 cells manufactured under GMP conditions showed increased memory subpopulations, reduced exhaustion markers and selective antitumor efficacy against MM cell lines and primary myeloma cells. The optimal release time points for obtaining the best fit product were > 6 and < 10 days (days 8-10). CONCLUSIONS: CARTemis-1 has been rationally designed to increase antitumor efficacy, overcome sBCMA inhibition, and incorporate the expression of a safety-gene. The generation of CARTemis-1 was successfully validated under GMP standards. A phase I/II clinical trial for patients with multiple myeloma will be conducted (EuCT number 2022-503063-15-00).
RESUMEN
Donor derived regulatory T lymphocytes and the JAK1/2 kinase inhibitor ruxolitinib are currently being evaluated as therapeutic options in the treatment of chronic graft versus host disease (cGvHD). In this work, we aimed to determine if the combined use of both agents can exert a synergistic effect in the treatment of GvHD. For this purpose, we studied the effect of this combination both in vitro and in a GvHD mouse model. Our results show that ruxolitinib favors the ratio of thymic regulatory T cells to conventional T cells in culture, without affecting the suppressive capacity of these Treg. The combination of ruxolitinib with Treg showed a higher efficacy as compared to each single treatment alone in our GvHD mouse model in terms of GvHD incidence, severity and survival without hampering graft versus leukemia effect. This beneficial effect correlated with the detection in the bone marrow of recipient mice of the infused donor allogeneic Treg after the adoptive transfer.