Introduction: Immunotherapy as a possible therapeutic option for cancer has been of great importance due to the innovative development of vaccines. Various molecules have been tested and emepepimut-S (Biomira Liposomal Peptide 25 (BLP 25)) has emerged as an option, particularly in lung cancer.Areas covered: A PubMed literature and ClinicalTrials.gov search was conducted using the terms: emepepimut, BLP25, NSCLC, cancer immunotherapy, cancer vaccine and MUC1. This review covers how emepepimut-S acts against the mucin 1 (MUC1) tumor-associated antigen producing a cellular immune response against the cells that express MUC1 and the most important clinical data available that led to the ongoing Phase III trial.Expert opinion: The results obtained in the Phase I/II trials are promising, showing a favorable toxicity with a benefit in survival in NSCLC patients. As future trials develop, demonstration of the long-term survival benefit, understanding of the various mechanisms of immune response initiated by the drug and the selection of patients that will highly benefit from the immunotherapy will be elucidated. The safety and extension in survival makes emepepimut-S a very interesting drug and could, therefore, offer a possibility of treatment and maintenance, particularly for good performance status patients with locally advanced NSCLC.