The investigational drug darolutamide can help delay the spread of prostate cancer to other parts of the body in men with nonmetastatic castration-resistant disease, according to results from a large clinical trial. In addition, the drug appears to lack some of the side effects seen with similar drugs used to treat men with this form of prostate cancer, the trial results showed. Until recently, there had been no effective treatment options for patients with nonmetastatic castration-resistant prostate cancer. These men have prostate tumors that continue to grow even after receiving androgen deprivation therapy (ADT) to keep androgen levels in the body extremely low or undetectable. But over the last 2 years, two drugs have been approved by the Food and Drug Administration (FDA) to treat this form of the disease and some researchers expect that, based on the results of this new trial, darolutamide may be next. The darolutamide findings, from an interim analysis of the ARAMIS trial, were published in the New England Journal of Medicine and presented at the American Society of Clinical Oncology Genitourinary Cancers Symposium in San Francisco on February 14. The incidence of side effects was generally similar between the darolutamide group and the placebo group, noted study coauthor Karim Fizazi, M.D., Ph.D., of the Gustave Roussy Institute, University of Paris, who presented the results in San Francisco. “This drug has a very favorable safety profile,” said Dr. Fizazi. Compared with placebo, darolutamide was not associated with a higher incidence of side effects such as seizures, falls, fractures, cognitive changes, or hypertension, he noted. The ARAMIS clinical trial results "strongly support the use of darolutamide” in patients with nonmetastatic castration-resistant prostate cancer, said William Dahut, M.D., head of the Prostate Cancer Clinical Research Section of NCI’s Center for Cancer Research. “I am cautiously optimistic that the central nervous system side effects will be less than they are with other drugs in this class,” added Dr. Dahut, who was not involved in the study.