Preliminary safety findings are presented from the open-label Phase I part of a combined Phase I/II study of BLP25 liposome vaccine (L-BLP25) in Japanese patients with unresectable Stage III non-small-cell lung cancer after primary chemoradiotherapy. Six patients received four or more once-weekly vaccinations with L-BLP25 1000 μg subcutaneously prior to a preliminary safety evaluation. Treatment continued with once-weekly vaccinations with L-BLP25 1000 μg subcutaneously until week 8, then maintenance vaccinations every 6 weeks until progressive disease. Cyclophosphamide (300 mg/m(2) i.v. single dose) was given 3 days before first vaccination. Median age was 63.5 years and performance status was 0-1. No serious adverse events occurred; none necessitated discontinuation. L-BLP25-related adverse events (Grade 1) were myalgia, arthralgia and nausea; cyclophosphamide-related adverse events comprised dysgeusia, anorexia and nausea. The first evaluation of L-BLP25 in Japanese patients shows that it is well tolerated, and the safety profile is consistent with that seen in previous studies of Caucasian patients.