Cleveland Clinic researchers are presenting updated findings from their novel study of a vaccine aimed at preventing triple-negative breast cancer, the most aggressive and lethal form of the disease.
The study team found that the investigational vaccine was generally well tolerated and produced an immune response in most patients. The team described the side effects of the vaccine, showed the highest tolerated dose to date, and presented the immunologic effects of the vaccine. Findings are being presented at the Society for Immunotherapy of Cancer Annual Meeting.
Launched in 2021 and funded by the U.S. Department of Defense, the ongoing clinical trial is evaluating safety and monitoring immune response of the vaccine. The phase 1 study, conducted at Cleveland Clinic’s main campus in partnership with Anixa Biosciences, has included 26 patients to date across three cohorts:
- Phase 1a - patients who completed treatment for early-stage, triple-negative breast cancer within the past three years and are currently tumour-free but at high risk for recurrence.
- Phase 1b - 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, these are women with BRCA1, BRCA2 and PALB2 mutations.
- Phase 1c - patients with early-stage triple-negative breast cancer 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.
Anixa 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.
“Triple-negative breast cancer is the form of the disease for which we have the least effective treatments,” said G Thomas Budd MD, of Cleveland Clinic’s Cancer Institute and principal investigator of the phase 1 study. “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.”
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 American Cancer Society. It is twice as likely to occur in Black women, and approximately 70-80% of the breast tumours that occur in women with mutations in the BRCA1 gene are triple-negative breast cancer.
The investigational vaccine is based on pre-clinical research led by the late Vincent Tuohy PhD, who was the Mort and Iris November Distinguished Chair in Innovative Breast Cancer Research at Cleveland Clinic’s Lerner Research Institute. Dr. Tuohy’s decades of groundbreaking research led to the development of this investigational vaccine. 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 tumour 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 tumours 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.