Purpose
Cabozantinib, an inhibitor of
tyrosine kinases including MET,
vascular endothelial growth factor receptors, and AXL, increased progression-free survival (PFS), overall survival (OS), and objective response rate (ORR) in patients with advanced
renal cell carcinoma (RCC) after previous
vascular endothelial growth factor receptor-targeted
therapy in the phase III METEOR trial. Because bone
metastases are associated with increased morbidity in patients with RCC, bone-related outcomes were analyzed in METEOR. Patients and Methods Six hundred fifty-eight patients were randomly assigned 1:1 to receive 60 mg
cabozantinib or 10 mg
everolimus. Prespecified subgroup analyses of PFS, OS, and ORR were conducted in patients grouped by baseline bone
metastases status per independent radiology committee (IRC). Additional end points included bone scan response per IRC, skeletal-related events, and changes in bone
biomarkers. Results For patients with bone
metastases at baseline (
cabozantinib [n = 77];
everolimus [n = 65]), median PFS was 7.4 months for
cabozantinib versus 2.7 months for
everolimus (hazard ratio, 0.33 [95% CI, 0.21 to 0.51]). Median OS was also longer with
cabozantinib (20.1 months v 12.1 months; hazard ratio, 0.54 [95% CI, 0.34 to 0.84]), and ORR per IRC was higher (17% v 0%). The rate of skeletal-related events was 23% with
cabozantinib and 29% with
everolimus, and bone scan response per IRC was 20% versus 10%, respectively. PFS, OS, and ORR were also improved with
cabozantinib in patients without bone
metastases. Changes in bone
biomarkers were greater with
cabozantinib than with
everolimus. The overall safety profiles of
cabozantinib and
everolimus in patients with bone
metastases were consistent with those observed in patients without bone
metastases. Conclusion
Cabozantinib treatment was associated with improved PFS, OS, and ORR when compared with
everolimus treatment in patients with advanced RCC and bone
metastases and represents a good treatment option for these patients.