58: Subgroup analyses of KEYNOTE-564: Adjuvant pembrolizumab for renal cell carcinoma (RCC) across UCLA Integrated Staging System (UISS) risk groups and disease stage
Associate Professor The University of Texas Southwestern Medical Center UT Southwestern Dallas, TX, United States
Background: Adjuvant pembrolizumab prolonged disease-free survival (DFS) in patients with RCC at increased risk of post-nephrectomy recurrence in the phase 3 KEYNOTE-564 study (NCT03142334). Post hoc exploratory analysis of DFS by UISS risk groups and disease stage in KEYNOTE-564 are reported.
Methods: Eligible patients with confirmed clear cell RCC were randomly assigned 1:1 to receive intravenous pembrolizumab 200 mg or placebo every 3 weeks for ≤17 cycles. DFS was assessed by investigator. UISS risk groups (intermediate risk [pT2, grade 4, N0, M0; pT3, grade 1, N0, M0; or pT3, grades 2-4, N0, M0, ECOG PS 0], high risk [pT3, grades 2-4, N0, M0, ECOG PS 1; pT4, any grade, N0, M0; or N1, M0], or M1 NED) were derived retrospectively from TNM stage, Fuhrman nuclear grade, and ECOG PS. Other subgroups based on disease stage were evaluated.
Results: Median follow-up was 30.1 months (range, 20.8-47.5). Of 994 enrolled patients, most had intermediate risk (n=732 [73.6%]; pembrolizumab, n=359; placebo, n=373); 195 (19.6%; pembrolizumab, n=100; placebo, n=95) had high risk and 58 (5.8%; pembrolizumab, n=29; placebo, n=29) had M1 NED. Hazard ratio (HR) for DFS was 0.65 (95% CI, 0.48-0.88; 24-month rates: pembrolizumab, 81.5%; placebo, 72.4%) in the intermediate-risk group, 0.77 (95% CI, 0.49-1.20; 24-month rates: pembrolizumab, 65.0%; placebo, 55.9%) in the high-risk group, and 0.28 (95% CI, 0.12-0.66; 24-month rates: pembrolizumab, 78.4%; placebo, 37.9%) in the M1 NED group. DFS by disease stage is reported in the Table.
