Pazopanib works against the management of advanced neuroendocrine tumors (NETs) even after a failure of previous treatments, according to the PAZONET study published online ahead of print in the journal Annals of Oncology.
The Spanish Task Force Group for NETs (GETNE) conducted a multicenter, open-label, phase 2 trial and assigned all 44 patients to receive pazopanib monotherapy.
The primary endpoint was clinical benefit rate (CBR) at 6 months, with traditional correlation of radiological response, progression-free survival (PFS) with circulating tumor cell (CTC) and tissue biomarkers, as the secondary endpoints.
Results showed that there was a variance in CBR according to prior therapies: multitarget inhibitors (73%), mTOR inhibitors (60%), and both agents (25%).
Researchers found that the median PFS was 9.5 months (95% CI: 4.8, 14.1) and lower baseline circulating CTC count had no significant increase in PFS with 9.1 months compared with 5.8 months (P=0.22).
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However, patients with VEGFR3rs307821 (HR=12.3; 95% CI: 1.09, 139.2; P=0.042) and rs307826 (HR= 6.9; 95% CI: 0.96, 49.9; P=0.055) polymorphisms wereshown to have reduced survival.
The study demonstrates that pazopanib shows activity among patients who previously failed treatment against NETs. Additional studies are warranted to investigate CTCs, soluble-s VEFGR-2 and VEGFR3 gene polymorphisms in NETs, as they wereshown to be potential biomarkers for pazopanib targeted therapy.