Researchers have uncovered insights into a novel investigational vaccine aimed at preventing triple-negative breast cancer. The findings by Rhoades et al were presented at the Society for Immunotherapy of Cancer (SITC) 2024 Annual Meeting (Abstract 631) and simultaneously published in the Journal for ImmunoTherapy of Cancer.
Background
There is a critical need to improve treatment options for patients with triple-negative breast cancer, which does not have biological characteristics that typically respond to hormonal or targeted therapies. Despite representing only about 10% to 15% of all breast cancer cases, triple-negative breast cancer accounts for a disproportionately higher percentage of breast cancer deaths, according to the American Cancer Society. The disease is twice as likely to occur in Black women, and approximately 70% to 80% of the breast tumors that occur in women with mutations in the BRCA1 gene are triple-negative breast cancer.
The novel investigational vaccine is based on preclinical research. The vaccine is capable of targeting a lactation protein known as alpha-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 prevent it from growing.
Previous research led by the late Vincent Tuohy, PhD, the Mort and Iris November Distinguished Chair in Innovative Breast Cancer Research at the Cleveland Clinic’s Lerner Research Institute, has indicated that activating the immune system against alpha-lactalbumin may be safe and effective in preventing breast tumors in mice.
“Triple-negative breast cancer is the [type] of the disease for which we have the least effective treatments,” stressed senior study author G. Thomas Budd, MD, of the Cleveland Clinic’s Cancer Institute. “Long term, we are hoping that this can be a true preventive vaccine that would be administered to [patients] who are cancer free to prevent them from developing this highly aggressive disease,” he added.
Study Methods and Results
The ongoing clinical trial, launched in 2021, is currently evaluating safety and monitoring the immune response of the vaccine. In the study, the researchers showed the highest tolerated dose of the vaccine to date, presented the immunologic effects of the vaccine, and described side effects of the treatment.
The phase I study included 26 patients across three cohorts: patients who completed treatment for early-stage, triple-negative breast cancer within the past 3 years and are currently tumor free but at high risk of cancer recurrence (phase Ia); patients who are cancer free and at high risk of developing breast cancer who elected to voluntarily have a preventive mastectomy to lower their risk and who primarily have BRCA1, BRCA2, and PALB2 mutations (phase Ib); and patients with early-stage, triple-negative breast cancer who are receiving preoperative chemoimmunotherapy and surgery and were treated with pembrolizumab following surgery and who have residual cancer in the breast tissue that makes them at high of cancer recurrence (phase Ic).
The researchers discovered that the vaccine was generally well tolerated and produced an immune response in a majority of the patients.
Conclusions
“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,” underscored Dr. Budd.
Anixa Biosciences, which partnered with the Cleveland Clinic to conduct the trial, is currently planning a phase II study to assess the efficacy of the vaccine. The trial is expected to begin in 2025 and is projected to last about 2 to 3 years.
Disclosure: The research in this study was funded by the U.S. Department of Defense. For full disclosures of the study authors, visit jitc.bmj.com.
