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. Patient summary: This study was conducted to indirectly compare the results of two immunotherapy-based combinations-nivolumab plus cabozantinib versus pembrolizumab plus axitinib-for patients who have not received any treatment for advanced renal cell carcinoma. Patients who received nivolumab plus cabozantinib had a significant improvement in the length of time without worsening of their disease and in their perceived physical and mental health compared with pembrolizumab plus axitinib; patients remained alive for a similar length of time from the start of either treatment. This analysis further adds to our current knowledge of the relative benefits of these two treatment regimens and will help with physician and patient treatment decisions.