Background: Current standard treatments for patients with metastatic renal cell carcinoma (mRCC) involve tyrosine kinase inhibitors (TKI) that inhibit angiogenesis. Cabozantinib is a multi TKI used for the treatment of mRCC in the first- and second-line setting.
Purpose: The aim of this study was the final analysis of treatment outcomes in patients with metastatic renal cell carcinoma (mRCC) treated with cabozantinib after previous targeted therapy.
Patients and methods: A total of 54 patients with mRCC from four oncology centers in the Czech Republic were evaluated retrospectively; the median follow-up was 18.5 months. Cabozantinib was administered in a dose of 60mg/day, a subset of patients received an initial dose of 40mg/day. The treatment was administered until the progression. The Kaplan-Meier analysis was used to calculate progression free survival (PFS) and overall survival (OS). We performed a multivariate analysis of risk factors for treatment outcomes (PFS, OS) by regression analysis. All statistics were evaluated at the significance level α = 0.05.
Results: The median PFS in all patients was 9.3 months (95% CI 7.2 - 11.4). The median OS in all patients was 21.9 months (95% CI 15.5 - 28.4). The median PFS in patients with bone metastases was not statistically significantly different compared with patients without bone metastases (9.3 vs 8.7 months, P = 0.53). The median OS in patients with bone metastases was statistically significantly shorter compared with patients without bone metastases (17.7 vs 26.8 months, P = 0.021). A treatment response was observed in 40.7 % of cases, including one complete remission. The regression analysis demonstrated a significant effect on OS in patients with the presence of subsequent treatment (P = 0.001), patients with treatment duration of first line therapy 6 months (P = 0.019) and 12 months (P = 0.003) and in patients without bone metastases (P = 0.021).
Conclusion: Our final analysis of patients with mRCC treated with cabozantinib after previous targeted therapy confirmed its effectiveness.
Keywords: cabozantinib; metastases; molecular targeted therapy; neoplasm metastasis; renal carcinoma; targeted treatment; treatment results.