Cancer Vaccine Study for Unresectable Stage III Non-small Cell Lung Cancer (START)

Ancillary Trial: An exploratory investigation of immune response in peripheral blood after tecemotide (L-BLP25) or placebo vaccination. The ancillary study is a sub-study within START. This is an exploratory investigation of the immune response in peripheral blood after tecemotide (L-BLP25) or placebo vaccination. The main objective is to evaluate whether administration of single-shot, low-dose cyclophosphamide followed by tecemotide (L-BLP25) vaccinations induces specific immune response in peripheral blood to BLP25 (the mucinous glycoprotein 1 \[MUC1\] antigen) as well as a modulation of cellular and soluble components of the immune response in subjects with unresectable stage III NSCLC. Twenty-five of the European START sites will participate in the ancillary study. Sample size: up to 60 to 80 subjects All inclusion criteria specified in the START clinical trial protocol except for hemoglobin \>= 100 gram/Liter (g/L) All exclusion criteria are the same as specified in the START clinical trial protocol Schedule of events: Blood samples will be taken at baseline, visit week 4, 8 13 and 25 (80 milliliter (mL) whole blood each)