A Multicenter Phase I Open-label Dose-escalation Vaccine Trial of dHER2 Protein With AS15 Adjuvant in HER2-overexpressing Patients With High-risk Breast Cancer

Treatment phase: 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. Five-year follow-up phase: This part of the study aims to assess any late onset toxicity of the study treatment through yearly follow-up visits and to monitor the patients' survival and disease status up to five years after the last administration of the study treatment. The patients' immune response is also measured to assess the robustness of the immune response elicited by the study treatment.