Sunitinib Rechallenge After Other Targeted Therapies in Metastatic Renal Cell Carcinoma Patients: A Single-Center, Retrospective Study

BACKGROUND: Sunitinib is still one of the standard therapies in metastatic renal cell carcinoma (mRCC). Despite the benefit of sunitinib resistance will develop in the majority of patients. Most of them receive multiple sequential therapies during the course of disease. OBJECTIVES: To retrospectively investigate the efficacy and safety of rechallenged sunitinib in third or later line settings. PATIENTS AND METHODS: Twenty-one mRCC patients were identified who received rechallenged sunitinib between March 2010 and April 2018. Patients received sunitinib in first or second line, then other tyrosine kinase and/or mTOR inhibitors were applied, then sunitinib was rechallenged. Patients’ characteristics, tolerability, treatment modalities, and treatment outcomes were recorded. The primary end-point was progression-free survival (PFS) of rechallenged sunitinib. RESULTS: Median age of patients was 62 years at the start of sunitinib rechallenge. Sixty-seven percent of patients were male. All patients had prior nephrectomy. Upon rechallenge 4 patients achieved partial response and 12 stable disease. The median PFS of first sunitinib treatment was 22 (95% CI 17–26) months and for rechallenged sunitinib 14 (95% CI 6–20) months. No increased severity of prior toxicity or new adverse events was reported during rechallenged sunitinib. The median overall survival (OS) from the start of first sunitinib was 67 (95% CI 46–76) months. Multivariate Cox regression analysis revealed that younger age (< 57 years) at start of first sunitinib (HR = 0.24; 95% CI 0.07–0.79; p = 0.019) and longer (> 2 years) first sunitinib treatment (HR = 0.28; 95% CI 0.09–0.93; p = 0.038) were independent markers of longer OS. CONCLUSION: Sunitinib rechallenge is a feasible and tolerable option with clinical benefit in selected mRCC patients.