• Posted October 8, 2024

New Hope Against Breast Cancers That Spread to the Brain

A recently approved targeted chemotherapy drug can significantly extend the lives of advanced breast cancer patients who have developed tumors in their brains, new clinical trial results show.

On average, patients receiving the drug Enhertu (trastuzumab deruxtecan) survived more than 17 months without any progression of their cancer, researchers reported Oct. 4 in the journal Nature Medicine.

More than 60% of patients survived 12 months without further tumor growth, results show.

And in those patients who’d developed brain tumors, more than 70% had their tumors shrink and 90% were alive a year after the start of their treatment, researchers found.

“These findings offer hope to patients with brain metastases in particular,” said co-lead researcher Dr. Nadia Harbeck, director of the breast cancer clinic at Ludwig-Maximilians University of Munich in Germany.

The U.S. Food and Drug Administration approved Enhertu in April for treatment of people with advanced HER2-positive cancers.

HER2 (human epidermal growth factor 2) is a protein that can promote the growth and spread of breast cancer. HER2-positive breast cancers account for up to 20% of all breast cancers, researchers said in background notes.

Enhertu contains trastuzumab and deruxtecan.

Trastuzumab is a monoclonal antibody that targets and attaches to HER2 proteins on a cancer cell. This allows deruxtecan -- a chemo drug -- to enter the cancer cell and kill it off, along with other tumor cells nearby.

“This is why we can use this active ingredient in the first place,” Harbeck said i a university news release. “Otherwise, it would be much too toxic.”

For this new clinical trial, researchers recruited more than 500 HER2-positive breast cancer patients, including 263 whose cancer had spread to their brain. These patients came from 78 cancer centers around the world.

The study was sponsored by the drug companies AstraZeneca and Daiichi Sankyou, which developed and market Enhertu.

More information

The American Cancer Society has more on HER2-positive breast cancers.

SOURCE: Ludwig-Maximilians University of Munich, news release, Oct. 4, 2024