The development and use of the E75 (HER2 369-377) peptide vaccine.

E75 (nelipepimut-S) is an immunogenic peptide derived from the HER2 protein. When combined with the immunoadjuvant granulocyte-macrophage colony-stimulating factor (GM-CSF), nelipepimut-S has been used as a vaccine that is capable of eliciting a robust anti-HER2 immune response. Early-phase clinical trials that enrolled women with node-positive or high-risk node-negative breast cancer who had been rendered disease free with standard of care therapy but were at risk for recurrence, demonstrated the vaccine to be safe with a suggestion of clinical benefit. Nelipepimut-S is currently being evaluated in a Phase III clinical trial. This article covers the preclinical and clinical development of nelipepimut-S.