 The purpose of this study is to evaluate the safety and the immune response elicited by a new anti-cancer therapy in patients with breast cancer in remission but who are at high risk of relapse. The study product is an immunotherapeutic consisting of the recombinant dHER2 protein combined with an immunostimulant called AS15. The study aims to determine the optimal of three different dose levels of dHER2 combined with the same fixed dose of AS15 by assessing the safety and the immune response elicited after a series of injections of the study product. 