Researchers Launch New Step in Study of Preventive Triple-Negative Breast Cancer Vaccine

Investigators at the Cleveland Clinic have launched the next step in a study of a preventive vaccine for triple-negative breast cancer (TNBC), the most lethal and aggressive form of the disease.

The vaccine targets a lactation protein, a-lactalbumin, which is no longer found after lactation in normal, aging tissues but is present in the majority of TNBC cases. If breast cancer develops, the vaccine is designed to prompt the immune system to attack the tumor and prevent its growth.

The new phase 1b study will enroll individuals without cancer who have a high risk of developing breast cancer, and who have voluntarily decided to undergo prophylactic mastectomy to lower their risk. Individuals in that population typically carry genetic mutations that put them at risk of TNBC or have high familial risk for any breast cancer.

The study, which will evaluate safety and monitor immune response, will include approximately 6 to 12 patients who will receive 3 vaccinations administered 2 weeks apart and will be closely monitored. It is anticipated to be completed by the end of 2023.

“[TNBC] is the form of the disease for which we have the least effective treatments,” said principal investigator G. Thomas Budd, MD, from the Cleveland Clinic’s Taussig Cancer Institute, in a press release. “Long term, we are hoping that this can be a true preventive vaccine that would be administered to cancer-free individuals to prevent them from developing this highly aggressive disease.”

The phase 1b trial follows a 1a study, which opened in 2021 and is expected to be complete in the fourth quarter of 2023. The phase 1a trial includes 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 recurrence.

Budd said there is a great need for improved treatments for this patient population. TNBC does not have biological characteristics that typically respond to hormonal or targeted therapies.

Despite representing approximately 12% to 15% of all breast cancers, TNBC accounts for a disproportionately higher percentage of deaths. It 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 TNBC.

The investigational vaccine is based on pre-clinical research led by the late Vincent Tuohy, PhD. Tuohy’s research showed that activating the immune system against a-lactalbumin was safe and effective in preventing breast tumors in mice.

“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,” Budd said in the press release.

REFERENCE

Cleveland Clinic Announces Next Step in Preventive Breast Cancer Vaccine Study. News release. Cleveland Clinic; February 8, 2023. Accessed February 24, 2023. https://newsroom.clevelandclinic.org/2023/02/08/cleveland-clinic-announces-next-step-in-preventive-breast-cancer-vaccine-study/