Breast Cancer Vaccine Shines in First Human Trial

By Holland Doran

March 14, 2014 | A new vaccine showed its potential to target breast cancer during a recently completed Phase I clinical trial, said Thomas Kieber-Emmons, Ph.D., who developed the vaccine at the University of Arkansas for Medical Sciences (UAMS).

The Phase I trial demonstrated the safety and tolerability of a peptide vaccine using a small group of participants who received five injections of the vaccine during a 23-week span.

The vaccine, which is a first of its type tested in humans, was shown to induce antibody responses in the subjects.

“We can induce antibodies that can successfully target and kill a range of human breast cancer cells, including some that are drug resistant,” said Kieber-Emmons, professor of pathology in the College of Medicine and holder of the Josetta Wilkins Chair of Breast Cancer Research at the UAMS Winthrop P. Rockefeller Cancer Institute. “This is an exciting finding to build upon.”

The vaccine was designed using a computer-generated chemical compound called a peptide to trigger an immune response that destroys the cancer cells. The peptide mimics carbohydrates that are attached to the cancer cells and tricks the immune system into attacking those carbohydrates.

“We converted the structure of a carbohydrate into a peptide,” Kieber-Emmons said. “Unlike carbohydrate vaccines, peptide vaccines are processed by the immune system. So by understanding how a carbohydrate binds to an antibody, we can reverse engineer a peptide so that it can induce the anti-tumor antibodies we want and activate the cellular responses we need.”

The participants for this Phase I trial were selected by Kieber-Emmons’ collaborator on the study, Laura Hutchins, M.D., professor in the Division of Hematology/Oncology in the UAMS College of Medicine.

A Phase II trial will begin in the next few months to examine if the vaccine improves the efficacy of preoperative chemotherapy. This trial will include a larger number of women who are newly diagnosed with breast cancer to determine if the combination of vaccine and standard chemotherapy improves the benefit from preoperative therapy.

The vaccine was developed by funding from a Clinical Translational Award from the Department of Defense Breast Cancer Program.