Cabozantinib in advanced renal cell carcinoma: A phase II, open-label, single-arm study of Japanese patients

To evaluate the efficacy and safety of cabozantinib, through a bridging study to METEOR, in Japanese patients with advanced renal cell carcinoma who had progressed after prior tyrosine kinase inhibitor therapy.

This phase II, open-label, single-arm study (ClinicalTrials.gov registration number: NCT03339219) included adult Japanese patients with advanced renal cell carcinoma and measurable disease who had received one or more tyrosine kinase inhibitors. Patients received cabozantinib 60 mg orally once daily while there was clinical benefit, or until unacceptable toxicity or disease progression. The primary end-point was objective response rate per Response Evaluation Criteria in Solid Tumors Version 1.1. Secondary end-points included clinical benefit rate (complete or partial response, or ≥8-week stable disease), progression-free survival, overall survival and safety.

Of the 35 patients enrolled, 68.6%, 22.9% and 8.6% had previously received one, two and three prior tyrosine kinase inhibitors, respectively. The median duration of cabozantinib exposure was 27.0 weeks (range 5.1-43.0 weeks). The objective response rate was 20.0% (90% confidence interval 9.8-34.3%), and the clinical benefit rate was 85.7% (95% confidence interval 69.7-95.2%). The 6-month estimated progression-free survival was 72.3% (95% confidence interval 53.3-84.6%); the median progression-free survival and overall survival were not reached. All patients reported adverse events, which were manageable by supportive treatment or dose modification; two patients (5.7%) discontinued therapy due to adverse events.

The results showed that findings from METEOR can be extrapolated, and that cabozantinib 60 mg/day is a viable treatment option in Japanese patients with advanced renal cell carcinoma who had progressed after prior tyrosine kinase inhibitor therapy.