This single-arm phase II study evaluated the tumor-vascular disrupting agent ASA404 (vadimezan, 5,6-dimethylxanthenone-4-acetic acid/DMXAA) 1800mg/m(2) plus standard therapy of carboplatin and paclitaxel in patients with advanced non-small cell lung cancer (NSCLC). This ASA404 dose is 50% higher than that used in previous phase II studies. Thirty patients with histologically confirmed stage IIIb or IV NSCLC previously untreated with chemotherapy received carboplatin AUC 6mg/mlmin plus paclitaxel 175mg/m(2) plus ASA404 1800mg/m(2) every 21 days for up to six cycles. The addition of ASA404 1800mg/m(2) to standard therapy produced little change in the systemic exposure of either total or free carboplatin or paclitaxel, and was generally well-tolerated, with no cardiac serious adverse events or clinically relevant ophthalmic abnormalities. The best overall tumor response was partial response, which was seen in 37.9% of patients by independent assessment and in 46.7% by investigator assessment. Stable disease was seen in 48.3% of patients by independent assessment and in 43.3% by investigator assessment. Median time to tumor progression was 5.5 months by investigator assessment and median survival was 14.9 months. The data from this trial corroborate findings from a recent randomized phase II trial, which suggested improvements in efficacy variables, including survival, when ASA404 1200mg/m(2) was added to standard therapy for advanced NSCLC. The manageable safety profile, lack of adverse pharmacokinetic interactions and efficacy outcomes seen in this single-arm study suggest that ASA404 1800mg/m(2) is a viable dose for future combination studies.