Sunitinib Rechallenge in Patients With Metastatic Renal Cell Carcinoma

We performed a retrospective study of patients with metastatic renal cell carcinoma treated with sunitinib in 2 different treatment lines at the Medical University of Vienna. The approach to rechallenge with sunitinib after the development of resistance appears to be a feasible strategy and might be especially important in areas where novel agents are not yet available. Background: Sunitinib has been the standard of care for patients with metastatic renal cell carcinoma (mRCC). However, nearly all patients will eventually develop resistance. Before the introduction of novel agents, few treatment options remained after sunitinib failure. Sunitinib rechallenge is a strategy based on the presumption that resistance might be only temporary. The aim of this analysis was to evaluate the efficacy and safety of sunitinib rechallenge in patients with mRCC. Patients and Methods: Patients who had undergone sunitinib rechallenge (SU2) at the Medical University of Vienna from 2010 to 2017 were identified for the present retrospective study. The primary endpoint was the treatment duration with rechallenge (TDSU2). The secondary endpoints included the treatment duration with upfront sunitinib (TDSU1), progression-free survival (PFSSU1 and PFSSU2), overall survival (OSSU1 and OSSU2), the objective response rate in both settings (ORRSU1 and ORRSU2), and toxicity. Results: A total of 31 patients were eligible. The median TDSU2 was 7.2 months, and the median TDSU1 was 17.8 months. The median OSSU1 and OSSU2 was 57.9 months and 14.7 months, respectively. The median PFSSU1 and PFSSU2 was 14.2 months and 5.6 months, respectively. The ORRSU1 and ORRSU2 was 34% and 16%, and another 48% and 42% achieved stable disease (SD), respectively. Fatigue and hypertension were the most common adverse events. Conclusions: Sunitinib rechallenge appears to benefit patients in later treatment lines. With the abundance of novel treatment options available, this approach might appear less relevant. However, novel agents are not yet available everywhere. Thus, sunitinib rechallenge could be an additional strategy to improve the outcomes of patients with mRCC.