A first-in-human phase I trial of NKG2D chimeric antigen receptor-T cells in AML/MDS and multiple myeloma.

TPS3102 Background: Canonical CAR-T cell constructs encode a single chain antibody variable fragment, costimulatory domain, and signaling domain of CD3 zeta. This restricts recognition to 1 tumor antigen and a limited set of cancers. This study employs a novel CAR fusing full-length human Natural Killer Group 2D (NKG2D) gene with the human CD3 zeta signaling domain. NKG2D CAR receives costimulation via naturally-expressed DAP10 and activates T cells directly to kill and secrete cytokines upon recognition of MIC-A, MIC-B, and UL-16 binding proteins. These NKG2D-ligands are upregulated in many solid tumors and hematologic malignancies but absent or poorly expressed on healthy tissues. In multiple murine cancer models, NKG2D CAR-T cells induced complete remissions, T-cell memory, and altered tumor microenvironment via cytokines. We demonstrated manufacture of autologous NKG2D CAR-T cells in a GMP-environment from healthy adults and patients with AML and myeloma was feasible. Following isolation of mononuclear cells, T cells are activated with anti-CD3 mAb and IL-2, undergo 2 transductions with SFG retroviral vector containing NKG2D CAR construct, and expand in media containing IL-2. Validation studies yielded consistent viability, robust cell expansion, high vector-driven NKG2D expression on T cells, potent IFN-g production during tumor cell co-culture, viral copy number/cell < 5, and no replication-competent retrovirus in NKG2D CAR-T (CM-CS1) cells. Methods: A phase 1 dose-escalation study to establish safety and feasibility of a single infusion of CM-CS1 T cells without lymphodepleting conditioning is currently enrolling subjects with AML/MDS-RAEB or relapsed/refractory progressive multiple myeloma without standard therapy options (ClinicalTrials.gov NCT02203825). Dose-escalation will proceed in 4 cohorts [1x106 to 3x107 CM-CS1 T cells] according to a 3+3 design followed by expansion cohorts at the MTDs in AML/MDS and myeloma for an anticipated 24 subjects. As of February, 2016, 6 subjects have been treated. Cohort 1 was completed without DLTs. Additional studies may include lymphodepletion, multiple infusions, and cytoreductive chemotherapy in both hematologic and solid tumor malignancies. Clinical trial information: NCT02203825.