Dr. Armstrong Discusses ARCHES Trial in Prostate Cancer

Andrew J. Armstrong, MD, associate professor of medicine and surgery, Department of Medicine, Duke University School of Medicine, Duke Cancer Institute, discusses the ARCHES trial in patients with metastatic hormone-sensitive prostate cancer.

The study, which was presented at the 2019 Genitourinary Cancers Symposium, was a global phase III randomized trial in 1150 men with metastatic prostate cancer who had just begun treatment with androgen deprivation therapy (ADT) or who had just completed treatment with docetaxel and ADT. The patients were randomized 1:1 to receive either ADT alone or ADT plus enzalutamide (Xtandi) at 160 mg daily.

The primary endpoint of the trial was radiographic progression-free survival (rPFS), which has been a regulatory accepted endpoint, similar to metastasis-free survival. Because these men had metastatic disease, the goal of the trial was to delay radiographic progression or death. This is a clinically meaningful endpoint, Armstrong says, because you are preventing the need for a change in therapy, pain progression, and overall quality of life deterioration. In other studies, improvements in rPFS have also been associated with long-term improvements in overall survival.

Findings from ARCHES demonstrated a 61% reduction in the risk of radiographic progression or death with the addition of enzalutamide to treatment.