Cabozantinib Superior to Sunitinib for First-line Treatment of mRCC

Among patients with intermediate- or poor-risk metastatic renal cell carcinoma (mRCC), first-line therapy with cabozantinib was superior to standard-of-care sunitinib with respect to objective response rate and progression-free survival, according to a study published in the Journal of Clinical Oncology.¹

Cabozantinib is an oral potent inhibitor of vascular endothelial growth factor receptor 2, MET, and AXL, approved for the treatment of patients with advanced RCC who have received prior anti-angiogenic therapy like sorafenib or sunitinib. It is also the first therapy to demonstrate improved overall survival, progression-free survival, and objective response rate in a phase 3 clinical trial of patients with advanced kidney cancer.

To evaluate the efficacy and safety of cabozantinib compared with sunitinib, researchers conducted the multicenter, phase 2 CABOSUN trial (ClinicalTrials.gov Identifier: NCT01835158). Investigators enrolled 157 patients with previously untreated mRCC who were intermediate- or poor-risk per International Metastatic Renal Cell Carcinoma Database Consortium criteria and randomly assigned them 1:1 to receive cabozantinib orally daily continuously or sunitinib orally daily for 4 weeks on, 2 weeks off.

Cabozantinib significantly reduced the risk of progression or death by 34% compared with sunitinib (adjusted hazard ratio, 0.66; 95% CI, 0.46-0.95; P = .012). Median progression-free survival was 8.2 months with cabozantinib and 5.6 months with sunitinib.

Investigators found that 46% (95% CI, 34-57) of patients treated with cabozantinib achieved an objective response, vs 18% of those given sunitinib.

The rate of all-causality grade 3 to 4 adverse events was similar between the 2 arms (67% for cabozantinib vs 68% for sunitnib). Fatigue and hematologic toxicities were more common with sunitinib, while hypertension and palmar-plantar erythrodysesthesia occurred more frequently in the cabozantinib arm.

The findings suggest cabozantinib as a potential new treatment option for treatment-naive patients with mRCC.

Reference

1. Choueiri TK, Halabi S, Sanford BL, et al. Cabozantinib versus sunitinib as initial targeted therapy for patients with metastatic renal cell carcinoma of poor or intermediate risk: The Alliance A031203 CABOSUN trial. J Clin Oncol. 2016 Nov 14. doi: 10.1200/JCO.2016.70.7398 [Epub ahead of print]