Importance: Clinical trial data on adjuvant therapy in patients with non-clear cell renal cell carcinoma (RCC) are scant.
Objective: To evaluate the effect of adjuvant everolimus after nephrectomy on recurrence-free survival (RFS) and overall survival (OS) in patients with localized papillary and chromophobe RCC.
Design, setting, and participants: This prespecified subgroup analysis of a phase 3 randomized clinical trial, EVEREST, included patients enrolled between April 1, 2011, and September 15, 2016. Eligible patients had fully resected RCC at intermediate-high risk (pT1 grade 3-4, N0 to pT3a grade 1-2, N0) or very-high risk (pT3a grade 3-4 to pT4 any grade or N+) for recurrence who had received radical or partial nephrectomy. Final analyses was completed in March 2022.
Intervention: The intervention group received 54 weeks of everolimus (10 mg orally daily); the control group received a matching placebo.
Main outcomes and measures: The main outcomes were RFS, OS, and rates of adverse events. For testing the hazard ratio (HR) for treatment effect, a Cox regression model was used for both OS and RFS.
Results: Of 1545 adult patients with treatment-naive, nonmetastatic, fully resected RCC in EVEREST, 109 had papillary RCC (median [range] age, 60 [19-81] years; 82 [75%] male; 50 patients [46%] with very high-risk disease) and 99 had chromophobe RCC (median [range] age 51 [18-71] years; 53 [54%] male; 34 patients [34%] with very high-risk disease). Among 57 patients with papillary RCC in the intervention group, 26 (46%) completed 54 weeks of treatment, and among 53 patients with chromophobe RCC in the intervention group, 26 (49%) completed 54 weeks of treatment. With a median (IQR) follow-up of 76 (61-96) months, adjuvant everolimus did not improve RFS compared with placebo in either papillary RCC (5-year RFS: 62% vs 70%; HR, 1.19; 95% CI, 0.61-2.33; P = .61) or chromophobe RCC (5-year RFS: 79% vs 77%; HR, 0.89; 95% CI, 0.37-2.13; P = .79). In the combined non-clear RCC cohort, grade 3 or higher adverse events occurred in 48% of patients who received everolimus and 9% of patients who received placebo.
Conclusions and relevance: In this clinical trial assessing the use of adjuvant everolimus, postoperative everolimus did not show evidence of improved RFS among patients with papillary or chromophobe RCC, and results from the study do not support adjuvant everolimus for this cohort. However, since the lower bounds of the 95% CIs were 0.61 and 0.89, respectively, potential treatment benefit in these subgroups cannot be ruled out.
Trial registration: ClinicalTrials.gov Identifier: NCT01120249.