The immunotherapy medication pembrolizumab, approved for the treatment of stage III and IV melanoma, has been shown to reduce post-surgery recurrence in patients with stage IIb and IIc melanoma.
These early findings were announced in a presentation on Sept. 18 at the ESMO (European Society for Medical Oncology) Congress 2021.
“Patients with stage IIb and IIc melanomas have a high level of risk for the disease coming back after surgery,” said study author Dr. Jason Luke, in a press release. “This is a very important clinical trial as it shows that pembrolizumab reduces that risk. Based on these results, I believe that we should be offering patients in this situation the opportunity to get this treatment after surgery.” Dr. Luke is director of the Cancer Immunotherapeutics Center at UPMC (University of Pittsburgh Medical Center) Hillman and associate professor of medicine at the University of Pittsburgh School of Medicine.
The findings come from the multi-country KEYNOTE-716 trial. This trial enrolled 976 patients with stage IIb or IIc melanoma. After surgery, 487 of the patients received intravenous pembrolizumab and 489 received a placebo every three weeks for one year.
Patients who received the drug had a 35% lower risk of death or melanoma relapse compared to those who got the placebo, with a median follow-up time of 14.4 months.
“The fact that patients in this trial had very rapid recurrences in distant organs—which is metastatic cancer—drives home the point that stage IIb and IIc melanomas are high risk,” said Dr. Luke. “There has been the idea that because these cancers don’t involve the lymph nodes, they’re not such a big deal. But that’s clearly wrong.”
The KEYNOTE-716 trial is ongoing, and the researchers will continue to monitor participants for cancer recurrence or death.
“The trial is still very early, and we expect to see the benefit of pembrolizumab increase above 35% over time,” said Dr. Luke.
A second part of the trial is planned in which patients in the placebo group who had their cancer return will be offered pembrolizumab. This will help clinicians determine whether it is better to give the treatment right after melanoma surgery or wait until the cancer returns, according to the release.
Roughly 18% of the participants in the pembrolizumab group experienced significant adverse events that required long-term hormone replacement. Dr. Luke said this was expected based on previous trials, and the research group did not observe any new or unexpected side effects.