Current status and future prospects of the strategy of combining CAR-T with PD-1 blockade for antitumor therapy (Review)

Abstract

The immune system serves an important role in controlling and eradicating malignant cells. Immunotherapy for treating tumors has received much attention in recent years due to its marked effect. There are two approaches which currently lead this field: Chimeric antigen receptor-modified T-cell immunotherapy (CAR-T) and programmed cell death protein-1 blockade (PD-1 blockade). CAR-T has emerged as a promising regimen for the treatment of a range of types of cancer, including chronic lymphoid leukemia and neuroblastoma, with studies of long term remission in certain patients. PD-1 blockade has been reported to exert marked clinical responses in patients against a range of types of solid cancer, including advanced melanoma, non-small-cell lung cancer and renal cell carcinoma, in addition to hematological malignancies. While increasing the power of the immune system to fight cancer has been a long-standing goal in oncology, a number of studies have demonstrated the synergistic antitumor effects of combination therapies under the umbrella of immunotherapy. The present review focused on a novel combination approach involving CAR-T and PD-1 blockade. The present reviews aimed to discuss the following four aspects of such an approach: i) Current monotherapy status; ii) rationale for the combination of CAR-T and PD-1 blockade; iii) current status of the combination of CAR-T and PD-1 blockade; and iv) conclusions and future perspectives.