Cleveland Clinic begins trial for breast cancer vaccine

CLEVELAND — Cleveland Clinic researchers have opened clinical trial for a vaccine that could prevent an aggressive form of breast cancer before it occurs, the Clinic announced Tuesday.

The proposed vaccine is aimed at potentially preventing triple-negative breast cancer, the most lethal form of the disease.

“This day has been more than two decades in the making,” Vincent Tuohy, the primary inventor of the vaccine and staff immunologist at Clinic’s Lerner Research Institute, said during a virtual press briefing Tuesday. Preclinical studies showed that a single vaccination could prevent breast tumors from occurring, and inhibit the growth of already existing breast tumors.

“If the vaccine is successful, it has the potential to transform the way we control adult onset cancers,” Tuohy said.

The Clinic is partnering with Anixa Biosciences, Inc., on the phase I trial to determine the maximum dose of the vaccine that is safe and effective in patients with early-stage triple-negative breast cancer.

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.

About 15% to 20% of women diagnosed with breast cancer worldwide have a form of the disease called triple negative breast cancer. This is any breast cancer that does not express the genes for estrogen receptor, progesterone receptor and Her2/neu. Because most hormone therapies target one of the three receptors, triple-negative cancers often require combination cancer-fighting therapies.

“Long term, we are hoping that this can be a true preventive vaccine that would be administered to healthy women to prevent them from developing triple-negative breast cancer, the form of breast cancer for which we have the least effective treatments.” said Dr. G. Thomas Budd of Cleveland Clinic’s Taussig Cancer Institute and principal investigator of the study.

Triple-negative breast cancer accounts for a disproportionately higher percentage of breast cancer deaths and has a higher rate of recurrence. This form of breast cancer is twice as likely to occur in Black women, and approximately 70% to 80% of the breast tumors that occur in women with BRCA1 gene mutations are triple-negative breast cancer, the Clinic said.

The reasons why triple-negative breast cancer rates are higher for Black women are not fully understood, Budd said. The Clinic’s vaccine trial will reach out to health care sites in neighborhoods with high minority populations in an effort to sign up people of color as trial participants, Budd said.

The vaccine would first be offered to patients at high genetic risk for breast cancer to spare them from undergoing preventative mastectomies, Budd said. But it will be several years before the proposed vaccine, if proven safe and effective, would be ready for patients.

The Clinic licensed the vaccine to Anixa Biosciences, Inc., a biotech company in San Jose, California. Tuohy will receive a portion of commercialization revenues received by the Clinic for this technology and also holds personal equity in the company.

The proposed vaccine activates the immune system against a breast-specific lactation protein present in the majority of triple-negative breast cancers, the Clinic said. The vaccine also allows the immune system to prevent emerging tumors from growing.

The study, funded by the U.S. Department of Defense, is based on pre-clinical research led by Tuohy and originally published in Nature Medicine.

The vaccine study will include 18 to 24 patients who have completed treatment for early-stage triple-negative breast cancer within the past three years and are currently tumor-free but at high risk for recurrence.

The study is open to non-clinic patients. Those interested can find more information about this study, including a description of the study and eligibility criteria on the Clinicaltrials.gov website at https://clinicaltrials.gov/ct2/show/nct04674306.

Study participants will receive three vaccinations, each two weeks apart, and will be closely monitored for side effects. The study is estimated to be completed in September.

Later trials will involve healthy, cancer-free women who have decided to undergo voluntary bilateral mastectomy because they are at high risk for developing breast cancer. Typically, those women carry mutations in either the BRCA1 or BRCA2 gene and are therefore at risk of developing triple-negative breast cancer, or whose family history put them at high risk for any form of breast cancer, the Clinic said.

This vaccine strategy could be applied to other types of breast cancer as well as ovarian and endometrial cancer, Tuohy said. If these vaccines are successful, they could allow physicians to control adult-onset cancers.