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

Treatment of metastatic renal-cell carcinoma (mRCC) may be associated with significant toxicities necessitating drug holidays. Outcomes of 112 patients who underwent drug holidays were analyzed. Complete response before the initial drug holiday was associated with a longer surveillance period (P =.0004), with median survival of 71.7 months. Select mRCC patients may be eligible for extended drug holidays. 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.