Association Between Time-of-Day of Immune Checkpoint Blockade Administration and Outcomes in Metastatic Renal Cell Carcinoma

Preclinical evidence demonstrating circadian rhythmicity within the immune system provides a rationale for hypothesis that immune checkpoint inhibitor (ICI) infusion time-of-day may serve as an actionable mechanism to improve outcomes. Herein, we explore the association between ICI time of infusion (TOI) and outcomes in metastatic renal cell carcinoma (mRCC).Data from patients with mRCC who received nivolumab or nivolumab/ipilimumab, in first- or second-line were retrospectively collected. Patients who received < 20% of infusions after 16:30 were assigned to the early TOI sub-cohort, while the rest were assigned to the late TOI sub-cohort. Clinical outcomes were compared across the 2 groups.Among 135 patients included, 89 (65.9%) and 46 (34.1%) were assigned to early and late TOI sub-cohorts, respectively. Baseline characteristics were comparable across the 2 sub-cohorts. Objective response rate (ORR) was 36.0% with early TOI versus 29.5% with late TOI (P = .157). Median time to treatment failure (TTF) was 9.5 months in the early TOI sub-cohort versus 4.6 months in the late TOI sub-cohort with a hazard ratio (HR) of 1.405 (95% CI, 0.919-2.149; P = .11) in univariate analysis and 1.694 (95% CI, 1.064-2.698; P = .026) in multivariate analysis. Higher cut offs allocating patients into the late TOI sub-cohort yielded an incremental increase in the HR for TTF and overall survival (OS) that reached statistical significance.In patients with mRCC, early TOI yielded a numerical increase in ORR, TTF and OS, with the TTF difference reaching significance in multivariate analysis. Prospective randomized studies are warranted to examine the impact of chronomodulation on outcomes with ICIs in mRCC.