ASCO: Pembrolizumab Ups DFS in High-Risk Resected Clear-Cell RCC
Estimated DFS rate 77.3 and 68.1 percent at 24 months with pembrolizumab versus placebo; benefit consistent across subgroups
FRIDAY, June 4, 2021 (HealthDay News) -- For patients with fully resected intermediate-high-risk or high-risk clear-cell renal cell carcinoma (ccRCC), adjuvant therapy with pembrolizumab yields a significant and clinically meaningful improvement in disease-free survival (DFS) compared with placebo, according to a study scheduled for presentation June 6 at the American Society of Clinical Oncology annual meeting.
Toni K. Choueiri, M.D., from the Dana-Farber Cancer Institute in Boston and colleagues examined pembrolizumab versus placebo as adjuvant therapy in a phase 3 trial involving patients with histologically confirmed high-risk ccRCC. Patients had undergone surgery within 12 weeks prior to randomization and were given study treatment for 17 cycles (about one year). A total of 994 patients were randomly assigned to pembrolizumab or placebo (496 and 498, respectively).
The researchers found that the primary end point of DFS was met at the first prespecified interim analysis (median not reached for both arms; hazard ratio, 0.68). At 24 months, the estimated DFS rate was 77.3 and 68.1 percent with pembrolizumab and placebo, respectively. Across subgroups, the DFS benefit was consistent. Fifty-one overall survival events were observed (18 and 33 in the pembrolizumab and placebo arms). At 24 months, the estimated overall survival was 96.6 and 93.5 percent for pembrolizumab versus placebo. Overall, 96.3 and 91.1 percent of patients experienced one or more all-cause adverse events with pembrolizumab and placebo, respectively. Grade 3 to 5 all-cause adverse events occurred in 32.4 and 17.7 percent, respectively.
"Pembrolizumab may provide a promising treatment for patients for whom there are few therapy options," Choueiri said in a statement.
Several authors disclosed ties to the pharmaceutical industry, including Merck & Co., whose subsidiary Merck Sharp & Dohme Corp., funded the study.