- Deniger, Drew C;
- Yu, Jianqiang;
- Huls, M Helen;
- Figliola, Matthew J;
- Mi, Tiejuan;
- Maiti, Sourindra N;
- Widhopf, George F;
- Hurton, Lenka V;
- Thokala, Radhika;
- Singh, Harjeet;
- Olivares, Simon;
- Champlin, Richard E;
- Wierda, William G;
- Kipps, Thomas J;
- Cooper, Laurence JN
- Editor(s): Unutmaz, Derya
T cells modified with chimeric antigen receptors (CARs) targeting CD19 demonstrated clinical activity against some B-cell malignancies. However, this is often accompanied by a loss of normal CD19+ B cells and humoral immunity. Receptor tyrosine kinase-like orphan receptor-1 (ROR1) is expressed on sub-populations of B-cell malignancies and solid tumors, but not by healthy B cells or normal post-partum tissues. Thus, adoptive transfer of T cells specific for ROR1 has potential to eliminate tumor cells and spare healthy tissues. To test this hypothesis, we developed CARs targeting ROR1 in order to generate T cells specific for malignant cells. Two Sleeping Beauty transposons were constructed with 2nd generation ROR1-specific CARs signaling through CD3ζ and either CD28 (designated ROR1RCD28) or CD137 (designated ROR1RCD137) and were introduced into T cells. We selected for T cells expressing CAR through co-culture with γ-irradiated activating and propagating cells (AaPC), which co-expressed ROR1 and co-stimulatory molecules. Numeric expansion over one month of co-culture on AaPC in presence of soluble interleukin (IL)-2 and IL-21 occurred and resulted in a diverse memory phenotype of CAR+ T cells as measured by non-enzymatic digital array (NanoString) and multi-panel flow cytometry. Such T cells produced interferon-γ and had specific cytotoxic activity against ROR1+ tumors. Moreover, such cells could eliminate ROR1+ tumor xenografts, especially T cells expressing ROR1RCD137. Clinical trials will investigate the ability of ROR1-specific CAR+ T cells to specifically eliminate tumor cells while maintaining normal B-cell repertoire.