Highlights in HER2-positive breast cancer

The 2023 edition of the San Antonio Breast Cancer Symposium featured the presentation of long-term follow-up data of the KATHERINE trial, confirming the long-term invasive disease free and overall survival benefit of T-DM1 over trastuzumab in patients with HER2+ breast cancer and residual disease after neoadjuvant therapy. ¹ In advanced HER2-positive breast cancer, HER2CLIMB02 showed that adding tucatinib to T-DM1 delays disease progression in previously treated patients, irrespective of the presence of brain metastases.² In addition, a phase II study showed a progression-free survival benefit for the addition of avelumab to vinorelbine and trastuzumab in heavily pre-treated patients with HER2+ metastatic breast cancer.³ Finally, first-line T-DM1 was found to be less effective than trastuzumab-pertuzumab-docetaxel in older patients with HER2+ advanced breast cancer although it did come with a lower toxicity burden.⁴