Donor-derived CD19 chimeric antigen receptor T cells

Building Potent Chimeric Antigen Receptor T Cells With CRISPR Genome Editing

Chimeric antigen receptor (CAR) T cells have shown great promise in the treatment of hematological and solid malignancies. However, despite the success of this field, there remain some major challenges, including accelerated T cell exhaustion, potential toxicities, and insertional oncogenesis. To overcome these limitations, recent advances in CRISPR technology have enabled targetable interventions of endogenous genes in human CAR T cells. These CRISPR genome editing approaches have unleashed the therapeutic potential of CAR T cell therapy. Here, we summarize the potential benefits, safety concerns, and difficulties in the generation of gene-edited CAR T cells using CRISPR technology.

Donor origin CAR T cells: graft versus malignancy effect without GVHD, a systematic review

CD19, CD20 chimeric antigen receptor T (CAR T) cell therapy has shown promising results for the treatment of relapsed or refractory hematological malignancies. Best results have been reported in acute lymphoblastic leukemia patients with a complete response rate above 80%. Patients who received donor-derived CAR T cells for the relapsed malignancy after stem cell transplantation (allogenic hematopoietic stem cell transplant) were identified from the published trials. A total of 72 patients from seven studies were treated with donor-derived CAR T cells. Only five out of 72 patients (6.9%) developed graft versus host disease. Use of donor-derived CAR T cell for relapse prophylaxis, minimal residual disease clearance or salvage from relapse is therefore highly effective, and risk of graft versus host disease flare is very low. Side effects include cytokine release syndrome, tumor lysis syndrome, B-cell aplasia along with CNS toxicity.

The Antitumor Efficacy of IL2/IL21-Cultured Polyfunctional Neu-Specific T Cells Is TNFα/IL17 Dependent

PURPOSE

Infusion of HER2-specific T cells, derived from vaccine-primed patients and expanded with IL2/IL12, has induced tumor regression in a minority of patients with metastatic treatment-refractory HER2(+) breast cancer. We questioned whether alteration of cytokine growth factors used to culture vaccine-primed T cells could improve antitumor activity.

EXPERIMENTAL DESIGN

Using the TgMMTV-neu murine mammary tumor model, we cultured T cells derived from mice immunized with a previously defined neu class II peptide, p98-114 (neu p98), and evaluated different cytokine combinations for expansion.

RESULTS

Infusion of neu p98-specific T-cell lines derived from all cytokine conditions evaluated resulted in significant antitumor activity compared with infused naïve splenocytes (P < 0.05). T cells cultured with IL2/IL21 could uniquely mediate complete regression of spontaneous mammary tumors. IL2/IL21 cultured neu-specific T cells demonstrated a different cytokine secretion pattern as compared with other cultured T cells; secreting high levels of TNFα and IL17 (P < 0.05). Moreover, tumor-infiltrating CD8(+) cells were significantly increased after the infusion of IL2/IL21 cultured T cells as compared with tumors treated with T cells expanded under other cytokine conditions (P < 0.001). The antitumor effect of the infusion of IL2/IL21 cultured cells was mediated by CD8 T cells. Depletion of TNFα or IL17, but not IFNγ, abrogated the tumor growth inhibition induced by the IL2/IL21 T cells and markedly decreased the influx of CD8 into tumors. Finally, IL2/IL21-cultured human antigen specific T cells also displayed a similar polyfunctional Th1/Th17 phenotype.

CONCLUSIONS

Expansion of HER2 vaccine-primed T cells with IL2/IL21 may have the potential to effectively mediate tumor regression when used in adoptive transfer. Clin Cancer Res; 22(9); 2207-16. ©2015 AACR.