Updated Efficacy and Safety Outcomes for Patients with Well-Differentiated Pancreatic Neuroendocrine Tumors Treated with Sunitinib

Background Sunitinib prolonged progression-free survival (PFS) versus placebo in patients with metastatic pancreatic neuroendocrine tumors (panNETs) in a phase III trial. The efficacy and safety of sunitinib in patients with panNETs were confirmed in an open-label phase IV trial. Objective To assess the clinical benefit with sunitinib using the combined data from these trials. Patients and methods An updated overall survival (OS) in patients with panNETs for the phase IV trial was provided, and an analysis of results from the sunitinib-treated combined cohort from the phase III and IV trials (combined cohort) was conducted to assess PFS, OS, and objective response rate (ORR). Results The updated median OS for the phase IV trial was 54.1 months (95% CI 37.9–not reached). Investigator-assessed median PFS for the combined cohort (n = 102) was 12.9 months (95% CI 7.4–16.7) with a significant benefit versus placebo in the phase III trial (n = 35) (HR 0.429; 95% CI 0.245–0.752; p = 0.001). Median OS could not be calculated for the combined cohort or placebo group due to the high number of patients censored; however, the estimated HR of 0.303 (CI 0.100–0.921; p = 0.013) favored sunitinib. ORR for the combined cohort was 16.7% (95% CI 10.0–25.3). Sunitinib was well tolerated in both trials with a safety profile similar to previously seen in other studies. Conclusions The combined analysis of these studies confirms the objective tumor responses and improvements in PFS observed in the initial phase III trial, providing further support for the clinical benefit of sunitinib in patients with advanced panNETs. ClinicalTrials.gov Identifiers NCT00428597 and NCT01525550.