"First-of-its-kind" trial will test preventative breast cancer vaccine

Researchers at the Cleveland Clinic have launched a first-of-its-kind study for a vaccine aimed at preventing lethal breast cancer.

Why it matters: Triple-negative breast cancer is considered one of the most aggressive types of breast cancer because it does not typically respond to hormonal or targeted therapies, researchers say.

• It represents roughly 10% to 15% of all breast cancers, but accounts for a disproportionately higher percentage of breast cancer deaths and has a higher rate of recurrence, according to the American Cancer Society.
• This type of breast cancer is also twice as likely to occur among Black women.

Details: The vaccine in the study targets a breast-specific lactation protein: α-lactalbumin. This protein is no longer found in normal, aging tissues post-location, but remains present in the majority of triple-negative breast cancers.

• Activating the immune system against α-lactalbumin provides pre-emptive immune protection.
• Pre-clinical research has shown that activating the immune system against this protein is effective in preventing breast tumors in mice.
• A single vaccination could prevent breast tumors from developing in mouse models, while also inhibiting the growth of existing tumors.

What to expect: The phase I trial will aim to determine the maximum tolerated vaccine dose in patients with early-stage triple-negative breast cancer.

• Participants will receive three vaccinations, each two weeks apart.
• The study, which is funded by the Department of Defense, is estimated to conclude in September 2022.
• A subsequent trial will involve cancer-free participants who decide to pursue voluntary bilateral mastectomies because they are at high risk for developing breast cancer, the clinic says.

What they're saying: "This vaccine approach represents a potential new way to control breast cancer," Vincent Tuohy, the primary inventor of the vaccine and a staff immunologist at Cleveland Clinic, said in a statement.

• "The long-term objective of this research is to determine if this vaccine can prevent breast cancer before it occurs, particularly the more aggressive forms of this disease that predominate in high-risk women."
• This vaccine strategy has "the potential to transform the way we control adult-onset cancers and enhance life expectancy in a manner similar to the impact that the childhood vaccination program has had," Tuohy added.