ABSTRACT
INTRODUCTION: Despite first-line approval in metastatic renal cell carcinoma (mRCC), the tyrosine kinase inhibitor cabozantinib is associated with frequent treatment-limiting side effects. Dose reductions in published trials of the drug and in clinical practice are commonplace. We analyzed our institution's real-world experience with cabozantinib dosing in patients with mRCC to assess strategies to improve tolerability and patient outcomes. OBJECTIVES: The purpose of our study is to retrospectively analyze dose intensity, tolerability, and duration of exposure in mRCC patients who received cabozantinib at our institution. METHODS: In this retrospective, single-center chart review, we identified 35 adult patients who received at least one cycle cabozantinib for mRCC during a two-year period. Dosing patterns were reviewed for each patient to allow calculation of median dose intensity and median duration of exposure. RESULTS: The median dose intensity for cabozantinib was 55.4% and the median actual daily dose was 33.2 mg. Median duration of cabozantinib exposure was 10.4 months. Several alternative dosing strategies were employed with 60% of patients requiring at least one dose intervention to manage toxicities. CONCLUSIONS: Patients in this analysis received a median actual daily dose of 33.4 mg, less than the reported median doses in the METEOR and CABOSUN trials. However, our median duration of cabozantinib treatment was 10.4 months compared to 8.3 months and 6.5 months in these respective trials. Further investigation is warranted to determine if alternative dosing strategies and lower median actual daily doses produce survival results comparable to published clinical trials.
