ESMO 2021 | Therapeutic landscape for patients with HER2-positive breast cancer with active brain metastases

Rupert Bartsch, MD, Medical University Vienna, Vienna, Austria, outlines the past, current and potential future treatments for HER2-positive breast cancer patients with active brain metastases and presents early data from the phase II TUXEDO-1 trial (NCT04752059). Previously, patients with active brain metastases were treated with stereotactic radiosurgery (SRS) and whole brain radiotherapy. Recently, a triple combination therapy consisting of tucatinib, trastuzumab and capecitabine was approved for the treatment of patients with metastatic HER2-positive breast cancer, including patients with active brain metastases based on data from the randomized phase II HER2CLIMB trial (NCT02614794). Due to the high number of patients progressing on this treatment, other systemic treatment options have been explored. This includes trastuzumab deruxtecan (T-DXd), an antibody-drug conjugate (ADC), which was approved following the DESTINY-Breast01 (NCT03248492) clinical trial, and that showed significantly improved outcomes for patients with metastatic breast cancer, including patients with stable brain metastases. The TUXEDO-1 trial evaluates T-DXd in patients with active brain metastases. Early data has shown a response rate over 80%, with 5 out of 6 patients responding to treatment. Further results are necessary to confirm the efficacy of this drug in this patient population. In addition, two other trials are assessing the efficacy of T-DXd in patients with active brain metastases. This interview took place at the European Society for Medical Oncology (ESMO) 2021 congress.