Abstract 1165P
Background
Surufatinib, a tyrosine kinase inhibitor targeting vascular endothelial growth factor receptors (1,2,3), fibroblast growth factor receptor 1 and colony stimulating factor 1 receptor, has demonstrated superior efficacy in extrapancreatic neuroendocrine tumors (NETs) in a phase III study (SANET-ep, ESMO 2019 Abs. LBA76). The proliferation marker Ki-67 and primary tumor origins are the major prognostic factors in NETs.
Methods
The post-hoc efficacy analysis of surufatinib versus placebo was conducted by Ki-67 subcategory (<3%, 3-10%, >10%) and primary tumor origins (foregut, midgut, hindgut, others or unknown) in patients (pts) with advanced well-differentiated (grade 1 or 2) extrapancreatic NETs. The primary endpoint (progression-free survival [PFS]) and secondary endpoint (objective response rate [ORR]) both by investigator assessment (RECIST1.1) were analyzed.
Results
Median PFS was significantly prolonged with surufatinib compared to placebo in subgroups of Ki-67 3-10% (7.6 vs 4.6 months [mo], hazard ratio [HR] 0.47, P=0.0012), Ki-67 >10% (8.3 vs 2.1 mo, HR 0.14, P<0.0001), foregut (8.4 vs 4.6 mo, HR 0.29, P=0.0001) and hindgut (8.3 vs 2.1 mo, HR 0.35, P=0.0014). There was numerical PFS improvement with surufatinib compared to placebo in the rest subgroups: Ki 67 <3% (13.9 vs 7.4 mo, HR 0.43, P=0.0557), midgut (19.2 vs 8.9 mo, HR not analyzed due to small sample size) and unknown origin (9.2 vs 5.5 mo, HR 0.56, P=0.2943). ORR in the subgroups of Ki-67 <3%, 3-10%, >10% with surufatinib were 4.8%, 7.7%% and 20.0% respectively. There was no objective response in the placebo arm. ORR in the subgroups of foregut, midgut and unknown origin with surufatinib was 18.4%, 16.7% and 10.0% respectively while no response was observed in subgroups of hindgut or other origins.
Conclusions
Surufatinib demonstrated clinically significant benefits for pts with advanced well-differentiated extrapancreatic NETs compared to placebo. Results of this exploratory analysis were consistent with those reported for the SANET-ep primary analysis, and improved outcomes were observed across major subgroups.
Clinical trial identification
NCT02588170.
Editorial acknowledgement
Legal entity responsible for the study
Hutchison MediPharma Limited.
Funding
Hutchison MediPharma Limited.
Disclosure
J. Li, J. He: Full/Part-time employment: Hutchison MediPharma Limited. W. Su: Shareholder/Stockholder/Stock options, Full/Part-time employment: Hutchison MediPharma Limited. All other authors have declared no conflicts of interest.