Research findings published in the journal Nature point to molecular changes within tumors that are preventing immunotherapy drugs from defeating cancer, reported Science Daily.
Clinical trials with PD-L1 and PD-1 blockade suggested that tumors with a high number of inflammation-causing T cells were more responsive to immunotherapy-based PD-L1 and PD-1 inhibitors, whereas those with low inflammation T cells were less responsive.
Senior author Weiping Zou said "we defined a molecular mechanism to explain why some tumors are inflamed and others are not, and consequently why some patients will be responsive to therapy and others not."
The scientists added that "if we can reprogram this epigenetic mechanism, then the therapy might work for more patients."
In the study, researchers examined human and mouse models of ovarian cancer cells. They applied epigenetic drugs and found that the numbers of T cells in the tumor increased, and also saw that epigenetic drugs synergized the anti-tumor effect of PD-L1 blockade in their models.
