Surufatinib in advanced extrapancreatic neuroendocrine tumours (SANET-ep): a randomised, double-blind, placebo-controlled, phase 3 study

Therapeutic options for advanced neuroendocrine tumours (NETs) are limited. We investigated the efficacy and safety of surufatinib (HMPL-012, sulfatinib) in patients with extrapancreatic NETs. SANET-ep was a randomised, double-blind, placebo-controlled, phase 3 trial undertaken at 24 hospitals across China. Patients (aged 18 years or older) with unresectable or metastatic, well differentiated, extrapancreatic NETs, with an Eastern Cooperative Oncology Group performance status of 0 or 1, and progression on no more than two types of previous systemic regimens were enrolled. Patients were centrally randomly assigned (2:1) using stratified block randomisation (block size 3) via an interactive web response system to receive oral surufatinib at 300 mg per day or matching placebo. Randomisation was stratified by tumour origin, pathological grade, and previous treatment. Patients, investigators, research staff and the sponsor study team were masked to treatment allocation. Crossover to the surufatinib group was allowed for patients in the placebo group at disease progression. The primary endpoint was investigator-assessed progression-free survival, which was analysed in the intention-to-treat population. A preplanned interim analysis was done at 70% of predicted progression-free survival events. This study was registered with ClinicalTrials.gov, NCT02588170. Follow-up is ongoing. Between Dec 9, 2015, and March 31, 2019, 198 patients were randomly assigned to surufatinib (n=129) or placebo (n=69). Median follow-up was 13·8 months (95% CI 11·1–16·7) in the surufatinib group and 16·6 months (9·2–not calculable) in the placebo group. Investigator-assessed median progression-free survival was 9·2 months (95% CI 7·4–11·1) in the surufatinib group versus 3·8 months (3·7–5·7) in the placebo group (hazard ratio 0·33; 95% CI 0·22–0·50; p