Abstract 5662
Background
The purpose of this study was to explore the efficacy and safety of everolimus administered as first-line treatment in newly diagnosed patients (pts) with metastatic or inoperable gastroenteropancreatic neuroendocrine tumors (GEPNETs).
Methods
This phase II, multicenter, single-arm clinical trial, included pts with advanced GEPNET of well or moderate differentiation and a Ki67<20%. Everolimus 10mg/day was administered until disease progression. All pts’ tumors were non-functioning; 18 pts (72%) received concomitantly octreotide long-acting release (LAR) 30mg/month. Endpoints of the study included progression-free survival (PFS), objective response to treatment (RECIST 1.1) and safety.
Results
After a median follow-up of 53 months, twenty-five pts (G1:11 pts, G2:14 pts; Ki67≤2%:11 pts, Ki67=3-19%:14 pts; pancreas:10 pts, GI:15 pts) received a median of 5 treatment cycles per patient. Centrally assessed radiographic responses in 23 evaluable patients included 43% PR, 48% SD and 9% PD. Of the 18 pts receiving octreotide LAR and everolimus, 9 patients had SD and 9 PR. The median PFS was 14.6 months, while the 15-months PFS rate was 48%. No fatal reaction occurred. Twenty-three grade 3-4 events were recorded (14 pts; 56%). Among them, 19 events were assessed as related to treatment and included stomatitis (G3: 3 pts; 12%), diarrhea (G3: 2 pts; 8%), CPK increase (2 pts; 8%), GGT increase (2 pts; 8%), hypokalemia/hypomagnesemia (1 pt; 4%), neutropenia (G3:1 pt; 4%), anemia (G3: 1 pt; 4%), and hyperglycemia (G3:1 pt; 4%). 8 serious adverse reactions to everolimus (6 pts; 24%) occurred. 6 (5 pts; 20%) were grade 3-4, namely mucositis G3/ bacteremia G3 (1 pt; 4%), pneumonia G3 (1 pt; 4%), diarrhea G3 (1 pt; 4%), and CPK G3 (1 pt; 4%) and G4 (1 pt; 4%). Baseline chromogranin A < 4x ULN was found to be associated with improved PFS as compared to higher values (HR = 0.34, 95% CI 0.11-1.02, Wald’s p = 0.055).
Conclusions
This prospective phase II study confirms everolimus's efficacy as upfront therapy and provides for the first time high rates of partial responses in advanced GEPNETs attributed to the combined effect of everolimus and octreotide LAR.
Clinical trial identification
NCT01648465.
Legal entity responsible for the study
Hellenic Cooperative Oncology Group.
Funding
Hellenic Cooperative Oncology Group, Novartis.
Editorial Acknowledgement
No
Disclosure
A. Koumarianou, D.G. Pectasides, G.A. Kaltsas, E. Samantas, G. Pentheroudakis: Honoraria for advisory board: Novartis. All other authors have declared no conflicts of interest.