Author Interviews, Breast Cancer, Vaccine Studies / 30.10.2016
First Steps Toward Breast Cancer Vaccine Using HER-2 Mimotope
MedicalResearch.com Interview with:
Josef Singer MD, PhD Comparative Medicine
Messerli Research Institute of the University of Veterinary Medicine
Medical University Vienna
University Vienna, Austria & Department for Comparative Immunology and Oncology Institute of Pathophysiology and Allergy Research Medical University
Department of Internal Medicine II University Hospital Krems Karl Landsteiner
University of Health Sciences Krems, Austria
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Immunotherapy of cancer has gained increasing interest in treatment of oncologic patients. Especially passive immunotherapy with monoclonal antibodies against tumor-associated antigens has been very successful due to good response rates with relatively moderate side effects compared to conventional chemotherapy.
Trastuzumab, an antibody against the human epidermal growth-factor receptor-2 (HER-2), is widely applied for the treatment of metastatic breast cancer. Trastuzumab leads to longer progression-free and overall survival in patients with HER-2 positive disease. However, monoclonal antibody therapies have to be repetitively applied, which represents a risk for infusion-related side effects and, due to the high costs, a massive burden for social security systems.
Our aim was to replace the passive immunotherapy by a vaccine actively inducing patients´ own antibodies with the same specificity as trastuzumab. A novel mimotope library platform enabled the development of a HER2-specific cancer vaccine: Mimotopes are small peptides that are able to mimic antibody epitopes on tumor-associated antigens, in our case the trastuzumab antigen on HER-2.
We use Adeno-associated-viruses (AAV) as carriers for our HER2 vaccine as they are highly immunogenic and safe. We could demonstrate that this HER-2 mimotope AAV-vaccine induced antibodies against human HER- 2 similar to the clinically used trastuzumab. In a mouse tumor model the HER-2 mimotope AAV vaccine was able to delay the growth of tumors significantly.
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