Cancer immunotherapy harnesses the body’s own immune system to recognize and attack tumor cells. It has become a central approach in oncology, particularly through immune checkpoint inhibitors, CAR T cell therapy and therapeutic cancer vaccines.

Immune checkpoint inhibitors target regulatory molecules, such as CTLA-4 and PD-1 on T cells or PD-L1 on tumor and immune cells. Tumors often exploit these checkpoints to suppress immune attack. Antibodies that block CTLA-4, PD-1 or PD-L1 can restore T cell activity and lead to durable responses in cancers like melanoma, lung cancer and others. However, not all patients respond, and immune-related side effects can be serious.

CAR T cell therapy involves engineering a patient’s T cells to express chimeric antigen receptors that recognize specific proteins on cancer cells. After expansion in the lab and reinfusion, these cells can rapidly kill target cells. CAR T therapies have shown remarkable success in some leukemias and lymphomas, but challenges include toxicity, limited effectiveness against solid tumors and potential relapse.

Therapeutic cancer vaccines aim to stimulate immunity against tumor-specific antigens, including neoantigens that arise from mutations. They can be made from peptides, nucleic acids or cells, and are being tested alone or combined with checkpoint inhibitors.

Current research focuses on understanding why some tumors are “hot” and immunogenic while others are “cold,” improving biomarkers that predict response and managing toxicity. Combination strategies that integrate immunotherapy with chemotherapy, targeted therapy, radiation or multiple immune agents are a major direction, with the goal of turning more cancers into curable diseases.