Abstract 5410
Background
Although standard therapy for gastroenteropancreatic neuroendocrine tumors (GEP-NETs) can provide symptom relief and delay tumour progression, new strategies are needed for patients with metastatic disease. The aim of this study was to investigate the antitumour activity and safety profile of pazopanib - a selective multi-targeted receptor tyrosine kinase inhibitor of vascular endothelial growth factor receptor and platelet-derived growth factor receptor.
Methods
We enrolled 124 patients with metastatic GEP-NETs. Pazopanib was administered orally at a dose of 800 mg daily with a 28-day cycle. The primary endpoint was overall response rate (ORR) according to Response Evaluation Criteria in Solid Tumors. The secondary endpoints were overall survival (OS), progression-free survival (PFS) at 6 months and safety profile of pazopanib (general tolerability and toxicity). The third endpoint was to compare the clinicopathological features of tumours and biomarker analysis with survival of the patients.
Results
The mean follow-up time was 196±87 days with a range of 67-268 days; 26 patients died within the observation time. 69% of the patients had confirmed pancreatic GEP-NET and 51% had colorectal, gastric and duodenal GEP-NET. 59 (47.6%) patients had G1, 34 (27.4%) G2 and 31 (25%) had G3 GEP-NET. ORR was 24% (19 of 124 patients), stable disease was achieved in 49 patients (39.5%) and PFS at 6 months was 36%. Median OS was 10.2 months (95% CI, 5.4-13.2 months). The most common grade 3-4 adverse events attributed to therapy were neutropenia (11%), proteinuria (14%), diarrhea (7%), and fatigue (12%). Patients with high CgA levels had the highest mortality risk (hazard ratio 3.478, 94% confidence interval 1.313-4.727, p 3000 ng/mL, range 8300-800 ng/mL) were associated with low survival independently from the Ki-67 score in a multivariate Cox regression model.
Conclusions
Pazopanib demonstrated a comparable therapeutic efficiency as well as a satisfying safety profile compared to other targeted agents in the treatment of patients with metastatic GEP-NETs.
Clinical trial identification
N/A
Legal entity responsible for the study
Faculty of Medicine Osijek
Funding
Faculty of Medicine Osijek
Disclosure
All authors have declared no conflicts of interest.