A Step Closer to a Breast Cancer Vaccine

Health Hub from Cleveland Clinic

Contributor: Vincent Tuohy, PhD

We just took a big step toward developing a preventive vaccine for the most dangerous type of breast cancer.

Cleveland Clinic Innovations has started a new company, Shield Biotech, to develop a vaccine based on our lab research. This research has shown that a vaccine designed for immune prevention of triple-negative breast cancer (TNBC) can work to both prevent and treat the disease.

We’re going to try to program the immune system to protect against breast and other cancers — in much the same way childhood vaccinations work to protect against polio and measles.

Now, after a three-year journey, raising money from all kinds of sources who believed in our project, we’ve finally secured the funds to continue development of the vaccine.

A shield against tumors

Our ultimate goal is to give women a defense or shield against developing breast cancer with targeted stimulation of the immune system. The best chance to prevent a tumor is by providing pre-emptive immunity that spots it early and kills it before it can grow.

Our early investigations were very promising. Our data showed that immune protection against breast cancer can be provided by vaccinating against proteins that are no longer expressed in aging breast tissues, but are overexpressed in TNBC.

Vaccination didn’t just inhibit the growth of preexisting tumors — it prevented new ones from forming.

Targeting a difficult-to-treat disease

Triple-negative breast cancer is the most aggressive and lethal form of the disease, the predominant form that occurs in women with BRCA1 mutations. As of now, TNBC has a higher recurrence rate than other forms of breast cancer and there’s no targeted therapy for it.

Our aim is to provide protection against recurrence for women diagnosed with the disease. And pre-emptive protection for healthy, cancer-free women against emerging breast tumors, giving them an effective, safe alternative to invasive prophylactic mastectomy.

How long to develop the vaccine?

We’re looking at a timeline of around 10 years before the vaccine would be available for women.

• It will take two years to complete preclinical studies and obtain permission from the FDA to test an investigational new drug.
• Shield Biotech will then initiate two Phase I clinical trials, to determine dosage and safety, that will take about three years to complete. We’ll be testing the vaccine in two groups: women with triple-negative breast cancer who have recovered from current standard of care; and healthy cancer-free women at high risk for developing breast cancer who have decided to undergo voluntary bilateral mastectomy to lower their risk.
• If these trials show the vaccine induces immunity and is safe, advanced Phase II and Phase III trials will show us how effective the vaccine is. It should take around five years before these more advanced trials get underway.

Development of a vaccine that will be widely available to prevent this breast cancer will take some time. But we’re well on our way toward discovering whether this vaccine will be effective.