Cabozantinib in the treatment of metastatic renal cell carcinoma - final data analysis from four oncology centers in the Czech Republic

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.

Patients with metastatic renal cell carcinoma treated with cabozantinib in the Czech Republic: analysis of four cancer centers

AIM

The aim of this study was to retrospectively analyze treatment outcomes and tolerance in patients in whom cabozantinib was used after previous targeted therapy.

PATIENTS AND METHODS

Cabozantinib was administered in dose 60 mg/day, a subset of patients received initial dose of 40 mg/day. The treatment was administered until to progression or unacceptable toxicity. CT scans were assessed according to the RECIST 1.1 and toxicity of treatment was assessed based on the CTCAE (version 4). 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 Cox regression analysis. All statistics were evaluated at the significance level alpha = 0.05.

RESULTS

54 patients with metastatic renal cell carcinoma (mRCC) were evaluated. Median PFS in all patients treated with cabozantinib was 9.3 months (95% CI 5.3 - 13.3). One-year survival was 85.2% (95% CI 72.9 - 93.4%). Treatment response was observed in 45.9% of cases, including one complete remission. Cox regression analysis demonstrated that presence of subsequent treatment was the only factor with a significant effect on OS (P=0.008). Adverse events occurred in 88.9% of patients, grade 3 - 4 in 46.3%.

CONCLUSION

The analysis of our cohort of patients treated with cabozantinib in the second or higher lines of treatment showed that cabozantinib represents an effective and safe therapy and contributes to longer survival of our mRCC patients.