A major trial has demonstrated, for the very first time, that the immunotherapy drug pembrolizumab is effective in treating advanced prostate cancer that did not respond to other treatments.

Share on Pinterest A new trial offers hope for those with advanced prostate cancer.

Immunotherapy is a form of treatment that can enhance one’s immune system in the fight against cancer.

Checkpoint inhibitors, in particular, are a type of drug that works by taking the “brakes” off of the immune system, releasing its T cells to attack cancer cells.

Previous research has shown immunotherapy to be particularly effective in treating cancers that have high levels of acquired genetic mutations, such as melanoma, lung cancer, and bladder cancer.

In prostate cancer, however, previous trials have suggested that immunotherapy does not work. But a new study examines the genetic makeup of prostate cancer tumors and shows that this approach singles out a group of patients for which the therapy might actually work.

In fact, the trial shows that 1 in 10 men who were failed by all other types of treatment have benefited from the checkpoint inhibitor drug pembrolizumab, and that for many of these patients, the benefits are still showing after a year.

The trial was carried out by researchers at the Institute of Cancer Research in collaboration with those at the Royal Marsden NHS Foundation Trust — both in London, the United Kingdom.

The results were presented at the annual meeting of the American Society of Clinical Oncology, held in Chicago, IL.