Drug Holiday in Metastatic Renal-Cell Carcinoma Patients Treated With Vascular Endothelial Growth Factor Receptor Inhibitors

Abstract Introduction Tyrosine kinase inhibitor (TKI) therapy in metastatic renal-cell carcinoma (mRCC) is noncurative and may be associated with significant toxicities. Some patients may receive treatment breaks as a result of TKI-related adverse effects or planned drug holidays. Patients and Methods In this retrospective study, mRCC patients who underwent drug holidays during TKI therapy at 2 different institutions were analyzed. A drug holiday was defined as a period of drug cessation for ≥ 3 months for reasons other than progressive disease. Results Of the 112 patients, the median duration of the first drug holiday for the overall cohort was 16.8 months (95% confidence interval, 12.5-26.4), and 40 patients (36%) remain on the first drug holiday. Overall, patients received a median of 2 lines of treatment. Complete response before the initial drug holiday (n = 14) was associated with a longer surveillance period ( P  = .0004). The observed median survival of this cohort was 71.7 months (range, 1.3 to 93+ months). Conclusion Some selected mRCC patients with a favorable response to TKIs may be eligible for drug holidays. The cohort evaluated in this retrospective study represents a highly selected group of patients with indolent disease biology.