Surufatinib in gevorderd neuroendocrine tumours: Final totale overleving from two randomised, double-blind, placebo-c...

BACKGROUND: SANET-ep (NCT02588170) and SANET-p (NCT02589821) demonstrated the efficacy and safety of surufatinib versus placebo in patients with advanced extra-pancreatic and pancreatic neuroendocrine tumours (NETs). Here, we present a pooled analysis of final overall survival (OS) from two randomised phase 3 studies. METHODS: The SANET studies were randomised, placebo-controlled, double-blind, phase 3 studies in China, comparing the efficacy and safety of oral 300-mg surufatinib (n = 265) versus placebo (n = 133) in patients with unresectable/metastatic, well-differentiated NETs (grade 1/2). After progression of disease or study unblinding, patients receiving placebo crossed over/switched to open-label surufatinib. By pooling the data from the two studies, OS analysis was completed using Kaplan-Meier methodology and a Cox proportional hazards model in the intention-to-treat population. Exploratory analyses were performed using different models to correct the confounding effect introduced by crossover. Long-term safety was assessed. RESULTS: At study termination, 69 % of the placebo group had crossed over/switched to surufatinib. Median OS was 50.1 versus 46.8 months for patients initially on surufatinib versus those initially on placebo (stratified hazard ratio [HR] 0.935, 95 % confidence interval [CI] 0.684-1.278; p = 0.6727). After correcting the confounding effect introduced by crossover/switching, the HR ranged from 0.558 to 0.825. Commonly (≥10 %) reported treatment-related adverse events (grade 3/4) included hypertension and proteinuria. CONCLUSION: OS of patients initially on surufatinib was not significantly longer versus patients initially on placebo, likely due to the high amount of crossover from placebo to surufatinib. No new safety signals were observed. CLINICAL TRIALS REGISTRATION: SANET-ep (NCT02588170) and SANET-p (NCT02589821).