Dr. Crew on New Research in Advanced HER2+ Breast Cancer

Katherine Crew, MD, MS, associate professor, Columbia University Irving Medical Center, discusses new research in the advanced HER2-positive breast cancer landscape.

At the 2019 San Antonio Breast Cancer Symposium, there were 5 trials presented in the HER2-positive breast cancer paradigm. Two of the trials were simultaneously published in the New England Journal of Medicine.

The first study, called HER2CLIMB, looked at a new TKI called tucatinib in the third-line metastatic setting with a heavily pretreated population. The other unique aspect of the study was that they included patients with untreated or progressing brain metastases; HER2-positive breast cancer has a propensity for going to the brain and up to 50% of patients with HER2-positive metastatic breast cancer can develop disease in the central nervous system. When tucatinib was added to trastuzumab (Herceptin) and capecitabine (Xeloda) chemotherapy, it led to a significant improvement in progression free survival (PFS) and overall survival. The HER2CLIMB study has changed the standard of care for patients in the third-line metastatic setting of HER2-positive disease, says Crew.

The other intriguing trial was DESTINY-Breast01; patients were treated with an antibody-drug conjugate called fam-trastuzumab deruxtecan-nxki (Enhertu). The open-label, single-group, phase II study showed that fam-trastuzumab deruxtecan-nxki elicited a high overall response rate in a heavily pretreated metastatic HER2-positive population. It more than doubled the PFS that is expected in such a population, concludes Crew.