Vandetanib versus erlotinib in patients with advanced non-small cell lung cancer (NSCLC) after failure of at least one prior cytotoxic chemotherapy: A randomized, double-blind phase III trial (ZEST)

Abstract

8009 Background: Vandetanib is a once-daily oral inhibitor of VEGFR, EGFR and RET signaling. This phase III study compared the efficacy of vandetanib vs erlotinib in patients (pts) with advanced, previously treated NSCLC. Methods: Eligible pts (stage IIIB/IV NSCLC, PS 0–2, 1–2 prior chemotherapies; all histologies permitted) were randomized 1:1 to receive vandetanib 300 mg/day or erlotinib 150 mg/day until progression/toxicity. The primary objective was to show superiority in progression-free survival (PFS) for vandetanib vs erlotinib. Secondary endpoints included overall survival (OS), objective response rate (ORR), time to deterioration of symptoms (TDS; EORTC QoL Questionnaire) and safety. Results: Between Oct 06-Nov 07, 1240 pts (mean age 61 yrs; 38% female; 22% squamous) were randomized to receive vandetanib (n=623) or erlotinib (n=617). Baseline characteristics were similar in both arms. Median duration of follow-up was 14 months, with 88% pts progressed and 67% dead. There was no difference in PFS for pts treated with vandetanib vs erlotinib (hazard ratio [HR] 0.98, 95.22% CI 0.87–1.10; P=0.721), and no difference in the secondary endpoints of OS (HR 1.01, 95.08% CI 0.89–1.16; P=0.830), ORR (both 12%) and TDS (pain: HR 0.92, P=0.289; dyspnea: HR 1.07, P=0.407; cough: HR 0.94, P=0.455). A preplanned non-inferiority analysis for PFS and OS demonstrated equivalent efficacy for vandetanib and erlotinib. The adverse events (AEs) observed for vandetanib were generally consistent with previous NSCLC studies with vandetanib 300 mg. There was a higher incidence of some AEs (any grade) with vandetanib vs erlotinib, including diarrhea (50% vs 38%) and hypertension (16% vs 2%); rash was more frequent with erlotinib (38% vs 28%). The overall incidence of CTCAE grade ≥3 AEs was also higher with vandetanib (50% vs 40%). The incidence of protocol-defined QTc prolongation in the vandetanib arm was 5%. Conclusions: The study did not meet its primary objective of demonstrating PFS prolongation with vandetanib vs erlotinib in pts with previously treated advanced NSCLC. However, vandetanib and erlotinib showed equivalent efficacy for PFS and OS in a preplanned non-inferiority analysis. [Table: see text]