Targeting T-cell malignancies using anti-CD4 CAR NK-92 cells

Abstract

Peripheral T-cell lymphomas (PTCLs) are a group of very aggressive non-Hodgkin's lymphomas (NHLs) with poor prognoses and account for a majority of T-cell malignancies. Overall, the standard of care for patients with T-cell malignancies is poorly established, and there is an urgent clinical need for a new approach. As demonstrated in B-cell malignancies, chimeric antigen receptor (CAR) immunotherapy provides great hope as a curative treatment regimen. Because PTCLs develop from mature T-cells, these NHLs are commonly CD4+, and CD4 is highly and uniformly expressed. Therefore, CD4 is an ideal target for PTCL CAR immunotherapy. To that effect, we created a robust third-generation anti-CD4 CAR construct (CD4CAR) and introduced it into clonal NK cells (NK-92). CD4CAR NK-92 cells specifically and robustly eliminated diverse CD4+ human T-cell leukemia and lymphoma cell lines (KARPAS-299, CCRF-CEM, and HL60) and patient samples ex vivo. Furthermore, CD4CAR NK-92 cells effectively targeted KARPAS-299 cells in vivo that modeled difficult-to-access lymphoma nodules, significantly prolonging survival. In our study, we present novel targeting of CD4 using CAR-modified NK cells, and demonstrate efficacy. Combined, our data support CD4CAR NK cell immunotherapy as a potential new avenue for the treatment of PTCLs and CD4+ T-cell malignancies.

Targeting T cell malignancies using CAR-based immunotherapy: challenges and potential solutions

“…Anti-CD4-CAR NK-92 cells have shown in vitro success eliminating PTCL cell lines and both adult and pediatric primary cells. Using a xenograft model in NSG mice, CD4-CAR NK-92 cell-treated mice demonstrate significantly prolonged survival compared to control-modified NK-92 cell-treated mice [54].…”

“…Various approaches have been used to overcome these challenges, including CRISPR-Cas9 genome editing to remove the antigen from the CAR T cells [45][46][47], Tet-OFF expression system to limit fratricide during ex vivo expansion [48], protein expression blocker (PEBL) to retain the antigen in the ER/Golgi to prevent cell surface expression [49,50], or using CAR-modified natural killer cells instead of T cells [47,[51][52][53][54]. Additionally, to date, four targets have been investigated as targets for CAR T cell therapy for the treatment of T cell malignancies with limited to no expression in the normal population of T cells, CD30, CD37, TRBC1, and CD1a [55][56][57][58].…”

“…As a result, fratricide was observed only transiently, allowing the CD5-CAR T cells to expand. These cells had significant Genome editing of target antigen [45][46][47] Targeting antigens with limited expression on T cells (e.g., CD30, CD37, TRBC1, CD1a) [55][56][57][58] Tet-OFF expression system [48] Protein expression blockers (PEBLs) [49] Using NK cells or NK-92 cells [47,[51][52][53][54]60] T cell aplasia Targeting antigens with limited expression on T cells (e.g., CD30, CD37, TRBC1, CD1a) [55][56][57][58] mRNA electroporation…”

“…Allogeneic CAR T cells with TRAC locus editing [46,61] Using NK cells or NK-92 cells [47,[51][52][53][54]60] Using γδ T cells in vitro cytotoxicity against two T-ALL cell lines and primary T-ALL cells and delayed leukemia progression in two different CD5-positive T-ALL models [59]. Based on these results, CD5-CAR T cells with a CD28 costimulatory domain are being tested in patients with relapsed or refractory T cell disease (MAGENTA trial, NCT03081910).…”

“…CAR-expressing NK-92 cells have been extensively assessed in preclinical studies targeting various cancers such as B cell malignancies [117][118][119], multiple myeloma [120], acute myeloid leukemia (AML) [121], breast carcinoma [122,123], neuroblastoma [124], and glioblastoma [125]. As previously discussed, multiple groups have initiated preclinical studies using CAR-modified NK-92 cells for the treatment of T cell malignancies, targeting antigens such as CD5, CD7, CD4, and CD3, demonstrating reduced tumor burden and an overall survival benefit in NSG mouse models of T cell leukemia [47,[52][53][54]60]. The safety and efficacy of NK-92 cells has been evaluated in clinical trials displaying a good safety profile with few mild to moderate adverse events [126][127][128] (NCT00900809, NCT00990717).…”