New drug could extend the lives of breast cancer patients

LMU researchers have successfully tested a new drug that can significantly extend the lives of breast cancer patients.

Patients with advanced HER2-positive breast cancer very often develop brain metastases. If this happens, patients with existing therapies such as surgery and radiation therapy will have little chance of survival in the next few years. Now an international team of researchers co-led by Professor Nadia Harbeck, director of the Breast Center at the LMU University Hospital, has tested a new drug in a clinical study. “With great results,” reports the oncologist. According to previous findings, survival times are significantly extended. The results of the study were published in the scientific journal Natural medicine.

Modern medicine divides breast cancer into different types according to tumor biological characteristics. 50% of patients with advanced breast cancer and the tissue marker HER2 develop brain metastases, which have not yet been successfully treated with medication because the blood-brain barrier often prevents active substances from penetrating the brain. New medications are therefore urgently needed.

Precisely targeted antibody

One of these active ingredients is a so-called antibody-drug conjugate (ADC) called “trastuzumab deruxtecan”. Trastuzumab is an antibody that, once injected into the body, docks precisely to the HER2 protein. Its payload is the drug deruxtecan, which kills cancer cells and is active in tumor tissue and little else in the rest of the body.

That's why we can use this active ingredient at all. Otherwise it would be far too toxic.”

Professor Nadia Harbeck, Director of the Breast Center at the LMU University Hospital

In order to determine the benefit of the ADC in HER2-positive breast cancer, the LMU oncologist started the DESTINY-Breast12 study as one of the two main researchers. The study involved over 500 patients with and without brain metastases from 78 cancer centers in Western Europe, Japan, Australia and the United States. The results showed that patients – including those with brain metastases – survived on average for more than 17 months without cancer progression. More than 60 percent of patients survived 12 months without further tumor growth. The researchers found regression of brain metastases in over 70 percent of the participants. 90 percent of all patients lived one year after starting treatment.

“These findings,” says Nadia Harbeck, “give hope to patients with brain metastases in particular.” The drug has already been approved for use in regular practice.

Overall, the cancer specialist attests that the ADC has “great potential for the treatment of breast cancer”. An example of this is the large ADAPT HER2 IV study, which has been running for a year on the initiative of the West German study group. This globally unique study is available to patients with early, non-metastatic HER2-positive breast cancer in Germany. The ADC is only infused into patients four times before the operation, which significantly simplifies and shortens therapy. A total of three ADCs are currently approved for breast cancer in Germany – “and I think,” says Harbeck, “there will be many more to come.”