Outcome of Restarted Sunitinib Treatment in Patients with Metastatic Renal Cell Carcinoma: a Retrospective Trial and Combined Case Reports from Literature.

In practice it is still not clear whether a drug holiday in sunitinib (Su) treatment can be safety, without impairing the overall outcome of patients with metastatic renal cell carcinoma (mRCC). The aim was to retrospectively evaluate the outcome in patients who restarted Su after an interruption of ≥3 months and a combined analysis of case studies from literature. From 556 patients treated between January 2006 and March 2016 a group of 38 patients were selected whose treatment was interrupted for other reasons than disease progression. During interruption Su was restarted in case of RECIST-defined progression. The primary objective was the objective response (OR) and progression free survival (PFS) of baseline and restarted therapy. The secondary objective was the overall survival (OS) calculated from the start of baseline treatment. Multivariate survival analysis was also applied. The major causes of interruption were toxicity (39%) and patient' choice (24%). Median duration of interruption was 7 (range 3-41) months. The OR of baseline and restarted treatment was 63% and 39%, respectively. After a median follow-up of 76 (95% CI 65-79) months the median PFS of baseline and restarted treatment was 21 (18-27) and 14 (10-18) months, respectively. The median OS was 61 (56-80) months. In multivariate analysis the lack of OR of restated treatment was an independent predictor of shorter PFS of restarted Su. According to our findings and also on combined case studies from literature restarted Su can be effective in selected cases of patients who progressed during treatment holiday.