Cleveland Clinic researchers have announced updated findings from their Phase 1 study of a novel vaccine aimed at preventing triple-negative breast cancer (TNBC), the most aggressive and lethal form of the disease. The study, presented at the Society for Immunotherapy of Cancer Annual Meeting, demonstrated that the investigational vaccine was generally well tolerated and produced an immune response in most patients.
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’s main campus in partnership with Anixa Biosciences, Inc., has included 26 patients to date across three cohorts: 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 1a); individuals who are cancer-free and at high risk for developing breast cancer who have elected to voluntarily have a preventative mastectomy to lower their risk, primarily women with BRCA1, BRCA2 and PALB2 mutations (Phase 1b); and patients with early-stage triple-negative breast cancer who have received preoperative chemoimmunotherapy and surgery, and are being treated with pembrolizumab following surgery, with residual cancer in the breast tissue, making them at risk of recurrence (Phase 1c).
G. Thomas Budd, M.D., of Cleveland Clinic’s Cancer Institute and principal investigator of the Phase 1 study, stated, "Triple-negative breast cancer is the form of the disease for which we have the least effective treatments. Long term, we are hoping that this can be a true preventive vaccine that would be administered to individuals who are cancer-free to prevent them from developing this highly aggressive disease."
The Need for New TNBC Treatments
According to Dr. Budd, there is a great need for improved treatments for triple-negative breast cancer, which does not have biological characteristics that typically respond to hormonal or targeted therapies. Despite representing only about 10-15% of all breast cancers, triple-negative breast cancer accounts 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 the breast tumors that occur in women with mutations in the BRCA1 gene are triple-negative breast cancer.
Vaccine Mechanism and Development
The investigational vaccine is based on pre-clinical research led by the late Vincent Tuohy, Ph.D. The vaccine targets a lactation protein, α-lactalbumin, which is no longer found after lactation in normal, aging breast tissues but is present in most triple-negative breast cancers. If breast cancer develops, the vaccine is designed to prompt the immune system to attack the tumor and keep it from growing.
The study is based on Dr. Tuohy’s research that showed that activating the immune system against α-lactalbumin was safe and effective in preventing breast tumors in mice. The research, originally published in Nature Medicine, was funded in part by philanthropic gifts from more than 20,000 people over the last 12 years.
Future Plans
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.
