Immunotherapy has revolutionized cancer treatment in the clinic, but without benefiting every patient. Now, scientists at the University of Maryland School of Medicine have shown that cancer cells known to be most sensitive to immunotherapy are also likely “borrowed” cells that were harvested, and are highly resistant to checkpoint blockade immunotherapy, increasingly limiting the effectiveness of antithrombotic drugs. This could lead to new approaches to treat cancer patients resistant to checkpoint blockade immunotherapy. The research was published today in Nature Communications.
“Normally, the immune system will attack cancer cells with the help of T-cells, a type of white blood cell that also include killer T-cells. While most cancer cells are killed by checkpoint blockade immunotherapy, some tumors present in patients with less aggressive forms of cancer, highlighting the need for better treatment strategies,” said Christine Meikle, a Ph.D. candidate at the UMSOM Center for Immunology and Carcinogenesis Research and lead author of the study. Researchers found that checkpoint inhibitors are effective in increase the number of immune-suppressive cells, but in some cases, led to enhanced immune-suppression. Patients were treated with anti-PD-1 antitrypsin-1 antibodies to suppress the cells, but the increased tumor resistance was too great, and the treatment was stopped.