A Phase I Study of CD19-Targeted 19(T2)28z1xx Chimeric Antigen Receptor (CAR) Modified T Cells in Adult Patients With Relapsed or Refractory B-cell Malignancies
The purpose of this study is to test the safety of 19(T2)28z1xx CAR T cells in people with relapsed/refractory B-cell cancers. The researchers will try to find the highest dose of 19(T2)28z1xx CAR T cells that causes few or mild side effects in participants. Once they find this dose, they can test it in future participants to see if it is effective in treating their relapsed/refractory B-cell cell cancers. This study will also look at whether 19(T2)28z1xx CAR T cells work against participants' cancer.
Tumor-targeted human T cells expressing CD28-based chimeric antigen receptors circumvent CTLA-4 inhibition
3区 · 综合性期刊
作者: Condomines, Maud ; Arnason, Jon ; Benjamin, Reuben ; Gunset, Gertrude ; Plotkin, Jason ; Sadelain, Michel
Adoptive T cell therapy represents a promising treatment for cancer. Human T cells engineered to express a chimeric antigen receptor (CAR) recognize and kill tumor cells in a MHC-unrestricted manner and persist in vivo when the CAR includes a CD28 costimulatory domain. However, the intensity of the CAR-mediated CD28 activation signal and its regulation by the CTLA-4 checkpoint are unknown. We investigated whether T cells expressing an anti-CD19, CD3 zeta and CD28-based CAR (19-28z) displayed the same proliferation and anti-tumor abilities than T cells expressing a CD3 zeta-based CAR (19z1) costimulated through the CD80/CD28, ligand/receptor pathway. Repeated in vitro antigen-specific stimulations indicated that 19-28z+ T cells secreted higher levels of Th1 cytokines and showed enhanced proliferation compared to those of 19z1+ or 19z1-CD80+ T cells. In an aggressive pre-B cell leukemia model, mice treated with 19-28z+ T cells had 10-fold reduced tumor progression compared to those treated with 19z1+ or 19z1-CD80+ T cells. shRNA-mediated CTLA-4 down-regulation in 19z1-CD80+ T cells significantly increased their in vivo expansion and anti-tumor properties, but had no effect in 19-28z+ T cells. Our results establish that CTLA-4 down-regulation may benefit human adoptive T cell therapy and demonstrate that CAR design can elude negative checkpoints to better sustain T cell function.