| Title: | Subgroup analysis by Ki-67 and primary tumor origins of the randomized, placebo-controlled phase 3 study of surufatinib in advanced well-differentiated extrapancreatic neuroendocrine tumors (SANET-ep) |
| Lead Author: | Zhiwei Zhou, Director, Department of Gastric and Pancreatic Surgery, Sun Yat-sen University Cancer Center |
| Session: | e-Poster Display Session |
| Abstract Number: | 1165P |
| Date available: | Thursday, September 17, 2020 |
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.
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.
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.
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.
Legal entity responsible for the study: Hutchison MediPharma Limited.
Funding: Hutchison MediPharma Limited.
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.