Overview

Researchers at the University of Washington School of Medicine have developed an experimental vaccine that could prevent or treat aggressive forms of breast cancer. The novel vaccine is “very safe” and a larger Phase II trial is now underway.

The science and other stuff to know

According to World Health Organization, more than seven million women suffer from breast cancer, making it one of the deadliest cancers. In 2022 alone, more than 43,000 women and 500 men in the U.S. could die of breast cancer, according to the National Breast Cancer Foundation. Yes, men, too, can have breast cancer. But it’s rare.

Thankfully, new research published in the journal JAMA Oncology hints we might soon be able to control the disease.

A team of researchers from the University of Washington School of Medicine conducted phase one trials for an experimental DNA vaccine against breast cancer. The vaccine proved “safe and highly effective” in preventing the growth of human epidermal growth receptor 2 (HER2), which regulates cell growth in normal cells. Cancer cells that produce too much HER2 may grow faster and spread to other parts of the body, and these HER2 tumor cells cause up to 30 percent of breast cancers.

In the trial, which began 20 years ago, the research team enrolled 66 patients with advanced HER2-positive breast cancer. They then administered three different doses to the volunteers, with the primary goal of evaluating the long-term safety of the vaccine.

Since HER2 proteins can be found in other cell types, the team planned a 10-year follow-up for each patient. This was to ensure there were no lingering problems of immune activity against healthy tissue.

“The results showed that the vaccine was very safe,” Mary Disis, lead author of the new study, said in a press release. “In fact, the most common side effects that we saw in about half the patients were very similar to what you see with COVID vaccines. [They include] redness and swelling at the injection site and maybe some fever, chills and flu-like symptoms.”

So what?

While the trial wasn’t geared to evaluate how effective the vaccine is at treating breast cancer, Disis points out that it showed promising early signs of efficacy.

“This particular vaccine directed against HER2 neu showed very interesting clinical results of those advanced stage breast cancer patients that we’ve now followed about ten years: 80 percent of them are still alive,” she told CBS News. “And that’s with Stage 3 and Stage 4 disease.”

Some cancers are aggressive and resist immunotherapy. However, researchers believe this vaccine could be used in the prevention or treatment of various forms of breast cancer.

What’s next?

A phase two trial of the vaccine is currently underway. The trial will test the efficacy of the vaccine in a larger cohort of HER2-positive patients.