SWOG S1801: Neoadjuvant and Adjuvant Pembrolizumab for Patients With Stage IIIB to IV Melanoma
Source: The Asco Post, September 2022
Patients with high-risk melanoma who received the anti–PD-1 therapy pembrolizumab both before and after surgery to remove cancerous tissue had a significantly lower risk of their cancer recurring than similar patients who received the drug only after surgery. These results from a study by the SWOG Cancer Research Network were presented during a Presidential Symposium at the European Society for Medical Oncology (ESMO) Congress 2022 (Abstract LBA6). The study—S1801—was led by Sapna Patel, MD, Chair of the SWOG Melanoma Committee and Associate Professor of Melanoma Medical Oncology at The University of Texas MD Anderson Cancer Center.
“It’s not just what you give, it’s when you give it. The S1801 study demonstrates the same treatment for resectable melanoma given before surgery can generate better outcomes,” Dr. Patel said. “In this case, we used the immune checkpoint inhibitor pembrolizumab. This treatment relies on the presence of preexisting T cells coming in contact with cancer cells in the body to generate an immune response, and we found that starting treatment before the melanoma is removed—and with it, the bulk of tumor-specific T cells—leads to a greater response than giving it after surgery.”
The mechanism of action of immune checkpoint inhibitors such as pembrolizumab is often described as “taking the brakes off” the immune system’s response to tumor cells. The S1801 researchers hypothesized that there would be a larger antitumor immune response and longer immunologic memory if pembrolizumab was administered while the melanoma tumor was still in the body as opposed to after that tumor had been removed, when the immune system would be responding primarily to micrometastatic cancer cells.