At a press conference at the 2021 ASTRO Annual Meeting, Steven J. Chmura, MD, PhD, Professor of Radiation Oncology and Scientific Director of the Cancer Clinical Trials Office, University of Chicago, commented on the CURB study results.

Steven J. Chmura, MD, PhD

“Most trials of stereotactic body radiation therapy (SBRT) have looked at patients with de novo metastatic disease who present with one or two metastatic spots. In fact, there are eight trials in this space,” he told listeners.

“With good systemic agents, we can shrink most of the disease and have just a few clones that spread. Now, we understand that a metastasis in the lungs is often different from one in the liver. Even if you have a great targeted drug, it is not unexpected that one or two spots may not be responding. This trial tests the hypothesis that if the first-line therapy is doing well, but the second-line therapy won’t work well, should we try to ablate these metastatic spots,” Dr. Chmura continued.

“This is an exciting trial, and since SBRT is widely available in 2021, these findings could be broadly applied. The investigators did a wonderful job stratifying by histologies. They showed a huge effect of SBRT in the lung but not in the breast arms. These different responses in cancer histologies demonstrate that we have to be specific in trial designs,” he noted.

“Other trials are enrolling in the oligoprogressive space. Some of these trials include all cancer histologies, and I don’t think they will be that useful. I am excited to see the results of the CURB trial and hope it will lead to a definitive phase III study,” Dr. Chmura concluded. 

DISCLOSURE: Dr. Chmura has received research support from BMS, Merck, AstraZeneca, and Varian; has served on an advisory board for Astrazeneca; and his spouse is employed by Astellas Pharma.