Patients with HER2-positive advanced breast cancer often develop brain metastases. When this occurs, the chances of survival for the next few years with current therapies, such as surgery and radiation therapy, are very low. However, an international team of researchers, co-led by Professor Nadia Harbeck, director of the Breast Center at LMU University Hospital, has tested a new drug in a clinical trial “with promising results,” according to the study. oncologist, since the data obtained so far shows that survival times have increased considerably.
Modern medicine classifies breast cancer into different types based on the biological characteristics of the tumor. 50% of patients with advanced breast cancer and the tissue marker HER2 will develop brain metastases, which until now have not been successfully treated with drugs, since the blood-brain barrier usually prevents active substances from reaching the brain. Therefore, there is a great need for new treatments. The results of the study have been published in Nature Medicine.
Greater disease-free survival in aggressive breast cancer
One of these new treatments is an antibody-drug conjugate (ADC) called “trastuzumab deruxtecan.” Trastuzumab is an antibody that, once injected into the body, specifically binds to the HER2 protein. Its payload is deruxtecan, an active agent that destroys cancer cells and acts primarily on tumor tissue, causing little impact on other areas of the body. “For this reason, we can use this active ingredient,” explains Harbeck. “Otherwise it would be too toxic.”
To evaluate the effectiveness of this ADC in HER2-positive breast cancer, the LMU oncologist launched the DESTINY-Breast12 study, which included more than 500 patients, with and without brain metastases, from 78 cancer centers in Western Europe, Japan, Australia and the United States. The results showed that, on average, patients, even those with brain metastases, survived more than 17 months without their cancer progressing.
More than 60% of patients survived 12 months without additional tumor growth. Regression of brain metastases was observed in more than 70% of participants. One year after starting treatment, 90% of patients were still alive. “These findings,” comments Nadia Harbeck, “give hope especially to patients with brain metastases.” The drug is already approved for use in routine clinical practice.
Regression of brain metastases was observed in more than 70% of the participants and one year after starting treatment, 90% of the patients were still alive.
In general, the cancer specialist highlights that this ADC has “great potential for the treatment of breast cancer.” One example is the large ADAPT HER2 IV study, which has been ongoing for the past year at the initiative of the West German study group. This trial, unique worldwide, is aimed at patients with early, non-metastatic, HER2-positive breast cancer in Germany.
Patients receive ADC infusions only four times before surgery, greatly simplifying and shortening therapy. Currently, there are three ADCs approved for the treatment of breast cancer in Germany, “and I believe,” Harbeck concludes, “that there will be many more in the future.”
