ERBB2-positive breast cancer, formerly known as HER2-positive breast cancer, is considered to be more aggressive than some other forms of breast cancer. Nevertheless, current survival rates for the condition exceed 90% when diagnosed early and treated with chemotherapy and dual antibody therapy. Chemotherapy regimens, however, incur significant side effects, meaning that patients may benefit from more effective and less toxic therapies.
In the current phase 1 trial, researchers investigated the safety and efficacy of a novel immunotherapy treatment for ERBB2 breast cancer. To do so, they recruited 12 patients, nine of whom had hormone receptor-positive disease and three: hormone receptor-negative disease. Altogether, five patients had stage 1 cancer, four had stage 2 cancer, and three had stage three cancer.
For the trial, the researchers removed dendritic cells from patients' bodies, reprogrammed them for anti-cancer activity, and then injected them into their breast tumors six times per week. Patients also received trastuzumab and pertuzumab- complementary monoclonal antibodies that target HER-2- intravenously every three weeks for six cycles followed by neoadjuvant chemotherapy.
Ultimately, eight of the 12 patients experienced a minimum 50% reduction in tumor volume after six weeks of immunotherapy. The most frequent adverse side effects were chills, fatigue, headache, and injection site reactions.
"We are hopeful that we will be able to use this new immunotherapy instead of chemotherapy, or at least dramatically reduce the need for chemotherapy, for all types of breast cancer," said study author Brian J. Czerniecki, M.D., Ph.D., chair and senior member in the Moffitt Cancer Center's Department of Breast Oncology in a press release.
The researchers have initiated a larger phase two trial to test the immunotherapy at higher doses.
Sources: Science Daily, JAMA Oncology