OBJECTIVES: We conducted an SLR of RCTs to evaluate intermediate and long-term efficacy measures, such as disease-free survival (DFS) and overall survival (OS), for adjuvant treatments in localized RCC.

METHODS: MEDLINE®, Embase, and CENTRAL databases were searched on 01/14/2022 with no publication date limits to identify RCTs evaluating OS and DFS, and endpoints with similar definition to DFS (recurrence-free survival [RFS], progression-free survival [PFS], and event-free survival [EFS]).

RESULTS: Of 4,158 identified records, this SLR included 18 RCTs (published between 1996-2022), 13 of which were phase 3 trials. Across all RCTs, sample size ranged from 46 to 1,943 patients (median=310) and follow-up ranged from 2.0 to 13.7 years (median=6.6 years). Most frequently studied interventions were interferon-alpha (IFN-α; n=3), sunitinib, sorafenib, and fluorouracil + IFN-α + interleukin-2 (n=2 each). Comparisons were against observation (n=10) or placebo (n=8). DFS hazard ratio (HR; n=10) ranged from 0.63 (pembrolizumab vs. placebo) to 1.50 (active specific immunotherapy vs. observation), of which three were significant (pembrolizumab vs. placebo, pazopanib vs. placebo, and sunitinib vs. placebo). RFS HR (n=6) ranged from 0.84 (IFN-α + interleukin-2 vs. observation) to 2.34 (thalidomide vs. observation). PFS HR (n=1) was 1.50 (IFN-α vs. observation) and EFS HR (n=1) was 1.41 (IFN-α vs. observation). HRs were not significant for these intermediate endpoints. OS HR (n=18) ranged from 0.52 (pembrolizumab vs. placebo) to 3.43 (IFN-α vs. observation), and was ≥1 in 10 trials and <1 in 8 trials. OS HR was statistically significant only for fluorouracil + IFN-α + interleukin-2 vs. observation. Age, gender, performance status, and disease histology were the most reported baseline patient characteristics and mostly well-balanced across trials.

CONCLUSIONS: Available evidence base indicated limited intermediate and long-term efficacy for several interventions highlighting the need for novel therapies and can be leveraged to inform surrogacy of DFS and its analogues for OS.