Moffitt Cancer Center researchers have discovered a promising new vaccine strategy for treating a specific type of breast cancer. The innovative approach targets human epidermal growth factor receptor 2-positive, estrogen receptor-negative (HER2-positive, ER-negative) breast cancer and has shown encouraging results in a recent pilot study. Published in npj Breast Cancer, the study combined the HER2-targeting dendritic cell vaccines with standard chemotherapy, demonstrating both safety and positive response rates.
The study enrolled 30 patients with stage 2 and stage 3 HER2-positive, ER-negative breast cancer who were undergoing chemotherapy before surgery to shrink the tumor. Researchers gave the HER2-directed dendritic cell vaccine before chemotherapy to determine its effects on immune response and treatment outcomes. The results showed that patients receiving the vaccine had significant immune activity, with complete tumor disappearance observed in a notable percentage of cases.
Our findings suggest that the dendritic cell vaccine can boost the body's immune response against tumors, potentially improving the effectiveness of chemotherapy. This approach may offer a new way to enhance breast cancer treatment and patient outcomes."
Hatem Soliman, M.D., medical oncologist in the Breast Oncology Department at Moffitt and lead author of the study
The study also found that injecting the vaccine directly into the tumor led to greater immune cell activity within the tumor environment. This could help refine future immunotherapy strategies for breast cancer and other types of cancer.
"These findings highlight the potential of immunotherapy to transform how we treat HER2-positive breast cancer," said Brian Czerniecki, M.D., Ph.D., co-author and chair of the Breast Oncology Department at Moffitt. "By stimulating the immune system, we may be able to create more effective, long-lasting responses for patients."
The study was supported by the National Institutes of Health (P30-CA076292) and the United States Department of Defense Breast Cancer Research Program (W81XWH-16-1-0385).
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Journal reference:
Soliman, H., et al. (2025). A pilot study incorporating HER2-directed dendritic cells into neoadjuvant therapy of early stage HER2+ER- breast cancer. npj Breast Cancer. doi.org/10.1038/s41523-025-00742-x.