In September, clinical research teams activated a phase 3 study, led locally by Yee Chung Cheng, MD, Associate Professor of Hematology, that evaluates a next-generation HER2-targeted therapy called zanidatamab for patients with metastatic HER2-positive breast cancer. The study compares zanidatamab combined with chemotherapy, to the current standard of care: trastuzumab with chemotherapy. “For patients whose disease has progressed after standard HER2 treatments, we need new options that can keep the cancer controlled and maintain quality of life,” said Dr. Cheng. “This study is an important opportunity to see whether zanidatamab can provide that next step forward.”
HER2-positive breast cancers produce high levels of a protein called HER2, which fuels tumor growth. Therapies like trastuzumab have been successful at blocking this protein, and newer drugs such as trastuzumab deruxtecan (T-DXd) have built on that success by delivering chemotherapy directly into cancer cells. While T-DXd has significantly improved outcomes, many patients eventually stop responding or cannot tolerate its side effects.
This new trial focuses on those patients, testing whether zanidatamab can be more effective after T-DXd treatment stops working. Zanidatamab attaches to two different parts of the HER2 receptor instead of one, helping block growth signals more completely and recruiting the immune system to destroy cancer cells. “Early research suggests this approach may extend control of the disease for patients who have few remaining treatment options,” explained Dr. Cheng.
Researchers will also assess safety, tolerability, and patient-reported outcomes to better understand how these treatments affect participants’ daily lives. The study, sponsored by Jazz Pharmaceuticals, is being conducted at multiple sites worldwide.
As one of the MCW Cancer Center’s priority areas, breast cancer research continues to advance through clinical trials like this one. During Breast Cancer Awareness Month, it stands as a powerful reminder of how science and care come together to improve outcomes for patients across Wisconsin and beyond.
“This trial represents the kind of research that moves the field forward,” said Dr. Cheng. “Each new generation of HER2 therapy helps us refine how we treat patients and brings us closer to making metastatic breast cancer a long-term, manageable condition.
Read about the research.