Cleveland Clinic researchers have released updated findings from their Phase 1 study of a novel vaccine designed to prevent triple-negative breast cancer (TNBC), the most aggressive and lethal form of the disease. The data, presented at the Society for Immunotherapy of Cancer Annual Meeting, indicate that the vaccine was generally well tolerated and elicited an immune response in the majority of patients. This investigational vaccine represents a significant step forward in addressing the unmet need for effective treatments for TNBC, which disproportionately affects Black women and those with BRCA1 mutations.
Phase 1 Trial Details
The ongoing clinical trial, launched in 2021 and funded by the U.S. Department of Defense, is evaluating the safety and immune response of the vaccine. The Phase 1 study, conducted at Cleveland Clinic in partnership with Anixa Biosciences, Inc., has enrolled 26 patients across three cohorts:
- Phase 1a: Patients who completed treatment for early-stage TNBC within the past three years and are currently tumor-free but at high risk for recurrence.
- Phase 1b: Cancer-free individuals at high risk for developing breast cancer who have elected to undergo preventative mastectomy, primarily women with BRCA1, BRCA2, and PALB2 mutations.
- Phase 1c: Patients with early-stage TNBC who have received preoperative chemoimmunotherapy and surgery and are being treated with pembrolizumab following surgery; these patients have residual cancer in the breast tissue, making them at risk of recurrence.
The study detailed the side effects of the vaccine, showed the highest tolerated dose to date, and presented the immunologic effects of the vaccine.
Targeting α-Lactalbumin
The investigational vaccine is based on preclinical research led by the late Vincent Tuohy, Ph.D. The vaccine targets α-lactalbumin, a lactation protein that is no longer found after lactation in normal, aging breast tissues but is present in most TNBCs. The vaccine is designed to stimulate the immune system to attack the tumor and prevent its growth if breast cancer develops.
Dr. Tuohy's research demonstrated that activating the immune system against α-lactalbumin was safe and effective in preventing breast tumors in mice, a finding originally published in Nature Medicine. According to G. Thomas Budd, M.D., of Cleveland Clinic's Cancer Institute and principal investigator of the Phase 1 study, "It was Dr. Tuohy's hope that this vaccine would demonstrate the potential of immunization as a new way to control breast cancer, and that a similar approach could someday be applied to other types of malignancy."
The Need for Improved TNBC Treatments
Triple-negative breast cancer lacks biological characteristics that typically respond to hormonal or targeted therapies. While it accounts for only 10-15% of all breast cancers, TNBC is responsible for a disproportionately higher percentage of breast cancer deaths, according to the American Cancer Society. It is twice as likely to occur in Black women, and approximately 70-80% of breast tumors in women with BRCA1 gene mutations are triple-negative.
Future Directions
Anixa Biosciences is planning a Phase 2 study to evaluate the efficacy of the vaccine. The trial is expected to begin in 2025 and is projected to last approximately two to three years. Anixa is the exclusive worldwide licensee of the novel breast cancer vaccine technology developed at Cleveland Clinic. Cleveland Clinic is entitled to royalties and other commercialization revenues from the company.
