Open-label, randomized multicentre phase II study to assess the efficacy and tolerability of sunitinib by dose administration regimen (dose modification or dose interruptions) in patients with advanced or metastatic renal cell carcinoma: study protocol of the SURF trial

Sunitinib is a tyrosine kinase inhibitor approved in the first-line metastatic renal cell carcinoma (MRCC) setting at the dose of 50 mg daily for 4 weeks followed by a pause of 2 weeks. Due to toxicity, this standard schedule (50 mg daily 4/2) can induce up to 50% of sunitinib dose modification (reduction and/or interruption). The current recommendation in such case is to reduce the dose to 37.5 mg per day (standard schedule 4/2). Recent data highlight an alternative schedule: 2 weeks of treatment followed by 1 week of pause (experimental schedule 2/1). The SURF trial is set up to evaluate prospectively experimental schedule 2/1 when toxicity occurs. This article displays the key elements of the study protocol.

SURF [NCT02689167] is a prospective, randomized, open-label phase IIb study. Patients are included at sunitinib initiation while receiving standard schedule 4/2 (50 mg daily) according to the marketing authorization indication. When a dose adjustment of sunitinib is required, patients are randomized between standard schedule 4/2 (37.5 mg daily) and experimental schedule 2/1 (50 mg daily). Key eligibility criteria are the following: patients with locally advanced inoperable or MRCC who are starting first-line treatment with sunitinib, with histologically or cytologically confirmed renal cancer clear cell variant or with a clear cell component, and with Karnofsky performance status ≥70%. The primary objective is to assess the median duration of sunitinib treatment (DOT) in each group. The key secondary objectives are progression-free survival, overall survival, time to randomization, objective response rate, safety, sunitinib dose intensity, health-related quality of life, and the description of main drivers triggering randomization. We hypothesized that experimental schedule 2/1 would result in an improvement in median DOT from 6 to 8.5 months. It was estimated that 112 patients would be needed in each arm during 24 months. In order to take into account the possibility of treatment discontinuation before randomization, 248 patients are necessary.

The SURF trial is asking a pragmatic question adapted to the current practice on what is the best way to adapt sunitinib when treatment-related adverse events occur. The results of the SURF trial will bring high-value data to support the use of an alternative schedule in sunitinib treatment.

ClinicalTrials.gov, NCT02689167. Registered on 26 February 2016.