L-BLP25: a MUC1-targeted peptide vaccine therapy in prostate cancer.

Renewed interest in cancer vaccine strategies has occurred with the identification of tumour-associated antigens and a further understanding of the immunoregulatory pathways involved in cancer development and progression. MUC1 is a mucinous glycoprotein that is overexpressed and aberrantly glycosylated in many human malignancies, including prostate cancer. BLP25 is a synthetic, liposomal cancer vaccine that targets the extracellular tandem repeat sequences of the MUC1 tumour-associated antigen. Preclinical L-BLP25 studies have shown the induction of a cell-mediated response and subsequent Phase I and II studies have established the vaccine dose, schedule and excellent safety profile. A Phase II study in advanced non-small cell lung cancer demonstrated a strong survival trend in favour of L-BLP25 in a subgroup of patients with locoregional stage IIIB disease. L-BLP25 also shows promise in prostate cancer. A pilot Phase II study in hormone naive patients with prostate-specific antigen failure after radical prostatectomy demonstrated a prolongation of prostate-specific antigen doubling time with little morbidity. These encouraging results suggest the potential of L-BLP25 in the management of cancer.