CAR-T cell therapy has demonstrated remarkable success in long-term remission of relapsed or refractory B-ALL. Unlike western countries, most of the relapsed/refractory B-ALL patients in India are unable to afford allogeneic stem cell transplant (allo-SCT), and simply choose palliation. To assess the potential use of CAR-T cells as a first line therapy, it is critical to evaluate CAR-T cell efficacy in patients unable to undergo allo-SCT. As a first step, a novel anti-CD19 CAR was designed and CD19-vector was produced using lentiviral mediated gene delivery system. To generate CD19+CAR T cells, T cells from healthy subjects were transduced and expanded either with rIL-2 or rIL-15. Almost 20-50% transduced T cells express CD19-CAR on their surface as analysed by flow cytometry. Next, efficacy of CD19-CAR-T cells was examined by cytotoxicity assay using CD19+ malignant B cell lines (Raji cells) and autologous B cells. CAR-T cells were able to kill majority of CD19+B cells effectively (100% killing). In addition, CAR-T cells secreted high levels of IFNΓ and IL-2. The CAR-T cells expanded in presence of rIL-15 showed fewer Treg compared to CAR-T cells expanded using rIL-2, however, there were no differences in numbers of T stem cells (TSC) and central memory T cells (TCM). In addition to data on healthy volunteers reflected above, results of above tests in relapsed/ refractory B-ALL patients is ongoing and being collated for inclusion in the final analysis. In conclusion, our data demonstrate the successful development of an indigenous CAR-T cell platform for subsequent use in clinical trials of CD19+B cell malignancies.

Citation Format: Alka Dwivedi, Sushant Kumar, Terry Fry, Gaurav Narula, Rahul Purwar. Evaluation of CD19 targeted T cells in relapsed or refractory ALL patients unable to afford allogenic bone marrow transplant in India [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 603. doi:10.1158/1538-7445.AM2017-603