The study, involving a cohort of 268 men with prostate cancer who had no other treatment options, found that more than 30% were alive 1 full year after being administered a new immunotherapy medication, Keytruda (generic: pembrolizumab).
More than one in 10 men had not seen their prostate cancer grow over the course of the trial, and the researchers are now trying to determine what factors allow some men to benefit more than others.
About 1 in 9 men will be diagnosed with prostate cancer at some time in their life, according to the American Cancer Society (ACS). The 1-year survival rate for men diagnosed with late-stage prostate cancer is 75%, which drops to roughly 25% at 5 years, ACS said.
Immunotherapy is designed to use a patient’s own immune system to fight a disease. This is done by stimulating the immune system to work more effectively in fighting off tumors, and by administering immune system components, such as man-made proteins.
“Our study has found that immunotherapy can benefit a subset of men with advanced, otherwise untreatable prostate cancer, and these are most likely to include patients who have specific DNA repair mutations within their tumors,” said Paul Workman, chief executive of ICR.
More clinical trials are needed to determine whether Keytruda could be a widely-used treatment option for men with late-stage prostate cancer.