A Matching-adjusted Indirect Comparison of Nivolumab Plus Cabozantinib Versus Pembrolizumab Plus Axitinib in Patients with Advanced Renal Cell Carcinoma

Background: The comparative efficacy and health-related quality of life (HRQoL) outcomes of nivolumab plus cabozantinib versus pembrolizumab plus axitinib as first-line treatments for advanced renal cell carcinoma (aRCC) have not been assessed in head-to-head trials.Objective: To assess the efficacy and HRQoL outcomes of nivolumab plus cabozantinib versus pembrolizumab plus axitinib.Design, setting, and participants: Patient-level data for nivolumab plus cabozantinib from the CheckMate 9ER trial and published data for pembrolizumab plus axitinib from the KEYNOTE-426 trial were used. CheckMate 9ER data were reweighted to match the key baseline characteristics as reported in KEYNOTE-426.Intervention: Nivolumab (240 mg every 2 wk) plus cabozantinib (40 mg once daily) and pembrolizumab (200 mg every 3 wk) plus axitinib (5 mg twice daily, initially).Outcome measurements and statistical analysis: Hazard ratios (HRs) for progression-free survival (PFS), duration of response, overall survival (OS), and deterioration in HRQoL were assessed using weighted Cox proportional-hazard models, with sunitinib as a common anchor. Objective response rates (ORRs) and changes in HRQoL scores from baseline were assessed as difference-in-differences for the two treatments relative to sunitinib.Results and limitations: After balancing patient characteristics between the trials, nivolumab plus cabozantinib was associated with significantly improved PFS (HR [95% confidence interval {CI}] 0.70 [0.53-0.93]; p = 0.01) and a significantly decreased risk of confirmed deterioration in HRQoL (Functional Assessment of Cancer Therapy-Kidney Symptom Index-Disease-related Symptoms: HR [95% CI] 0.48 [0.34-0.69]) versus pembrolizumab plus axitinib. OS was similar between treatments (HR [95% CI] 0.99 [0.67- 1.44]; p = 0.94). Nivolumab plus cabozantinib was associated with numerically greater ORRs (difference-in-difference [95% CI] 8.4% [-1.7 to 18.4]; p = 0.10) and longer duration of response (HR [95% CI] 0.79 [0.47-1.31]; p = 0.36) than pembrolizumab plus axitinib. Comparative studies using data with a longer duration of follow-up are warranted.Conclusions: Nivolumab plus cabozantinib significantly improved PFS and HRQoL compared with pembrolizumab plus axitinib as first-line treatment for aRCC.