Researchers discover new drug that helps breast cancer patients live longer and better lives

LMU researchers have successfully tested a new drug that can significantly extend the lives of breast cancer patients. Brain metastases are frequently seen in patients with advanced HER2-positive breast cancer. Patients who experience this are less likely to survive for the next few years while receiving current treatments such as radiotherapy and surgery. A new drug has now been investigated in a clinical study by an international team of researchers co-led by Professor Nadia Harbeck, Director of the Breast Center at LMU University Hospital.

Promising advances in breast cancer treatment

“With good results,” the oncologist reports. According to the findings to date, survival times have increased significantly. The results of the trial have been published in the journal Nature Medicine. Modern medicine divides breast cancer into different types according to tumorbiological characteristics. Up to 50% of patients with advanced breast cancer and the tissue marker HER2 will suffer from brain metastases, which has not been possible to treat successfully with drugs before, because the blood-brain barrier often prevents active substances from entering the brain. Therefore there is an urgent need for new medicines.

One of these active substances is a so-called antibody-drug conjugate (ADC) called “trastuzumab deruxtecan”. Trastuzumab is an antibody that, once injected into the body, attaches to the HER2 protein. Its payload is the active ingredient deruxtecan, which kills cancer cells and is active in tumor tissue and is rarely active elsewhere in the body. “That’s why we can use this active ingredient in the first place,” Harbeck explains. “Otherwise, it would be too toxic.”

A game-changing antibody-drug conjugate

To determine the benefit of ADCs for HER2-positive breast cancer, LMU oncologists initiated the DESTINY-Breast12 study as one of two lead investigators. More than 500 patients with and without brain metastases from 78 cancer centers in Western Europe, Japan, Australia and the United States participated in the trial. The results showed that on average, patients – even those with brain metastases – lived longer than 17 months without cancer progression. More than 60 percent of patients survived 12 months without further tumor growth. Researchers detected regression of brain metastases in more than 70 percent of the participants. 90 percent of all patients were alive one year after treatment started. “These findings provide hope especially to patients with brain metastases,” says Nadia Harbek. The drug is already approved for use in standard practice.

Overall, cancer experts testify that ADCs “have great potential for the treatment of breast cancer.” An example of this is a large trial, ADAPT HER2 IV, which has been running for the past year at the initiative of a West German study group. This worldwide unique trial is available to patients with early, non-metastasized HER2-positive breast cancer in Germany. Patients are given ADC infusions only four times before surgery, which significantly simplifies and shortens the treatment. In total, there are three ADCs currently approved for breast cancer in Germany – “and I think,” says Harbach, “there are still more to come.”