About the EXTEND Trial of Patients With Oligometastatic Prostate Cancer

Chad Tang, MD, The University of Texas MD Anderson Cancer Center, discusses the design of the randomized, phase 2, basket EXTEND trial (NCT03599765).

In EXTEND, investigators examined whether or not the addition of metastasis directed therapy improved progression-free survival in men with oligometastatic solid tumors, including prostate cancer.

Patients were randomly assigned to continue hormone therapy with or without metastasis directed therapy after at least 2 months of hormone therapy alone. Hormone therapy was then stopped 6 months after enrollment and patients did not resume until progression.

Transcription:

0:08 | EXTEND is a basket study, which means we were looking at multiple histologies where each basket is powered by itself to look at a question. In this intermittent hormone therapy basket, patients with oligometastatic prostate cancer chosen to be on intermittent hormone therapy were randomized to radiation therapy versus not. Then the hormone therapy was stopped 6 months later, so you get a minimum of 8 months, because you needed 2-4 months before.

0:46 | This kind of mirrors an intermittent hormone regime. Then, patients were monitored and when their PSA [prostate specific antigen] rises, we call it progression when they meet certain thresholds, you put the patient's back on hormone therapy. The primary end point was progression-free survival, which could be from PSA or from your graphical assessment. Secondarily, we were trying to see how long patients could be off the hormones and have normal testosterone because all men who were on hormone therapy hate it. They want their testosterone back as it is a big quality of life impact for them.