Vandetanib Versus Placebo in Patients With Advanced Non–Small-Cell Lung Cancer After Prior Therapy With an Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor: A Randomized, Double-Blind Phase III Trial (ZEPHYR)

Abstract

Vandetanib is a once-daily oral inhibitor of vascular endothelial growth factor receptor, epidermal growth factor receptor (EGFR), and RET signaling. This placebo-controlled trial assessed whether vandetanib conferred an overall survival benefit in patients with advanced non-small-cell lung cancer (NSCLC) after prior treatment with an EGFR tyrosine kinase inhibitor and one or two chemotherapy regimens. Eligible patients were randomly assigned 2:1 to receive vandetanib 300 mg/d or placebo until disease progression or unacceptable toxicity. The primary objective was to compare the outcomes between the two arms with respect to overall survival. Overall, 924 patients received vandetanib (n = 617) or placebo (n = 307). No significant increase in overall survival was detected in the vandetanib cohort compared with placebo (hazard ratio = 0.95; 95.2% CI, 0.81 to 1.11; P = .527); median overall survival was 8.5 months versus 7.8 months for vandetanib and placebo patients, respectively. Statistically significant advantages favoring vandetanib were observed for progression-free survival (hazard ratio = 0.63; P < .001) and objective response rate (2.6% v 0.7%; P = .028). Postprogression therapy was balanced across the cohorts in both number and type. Adverse events were generally consistent with previous NSCLC studies of vandetanib 300 mg; common events occurring with a greater frequency in the vandetanib arm versus placebo included diarrhea (46% v 11%), rash (42% v 11%), and hypertension (26% v 3%). The study did not demonstrate an overall survival benefit for vandetanib versus placebo. There was a higher incidence of some adverse events with vandetanib.