Trastuzumab deruxtecan for the treatment of patients with HER2-positive breast cancer with brain and/or leptomeningeal metastases: an updated overall survival analysis using data from a multicenter retrospective study (ROSET-BM).

Abstract

We provide updated results (median follow-up duration: 20.4 months) of a retrospective study on the effectiveness of trastuzumab deruxtecan (T-DXd) in patients with human epidermal growth factor receptor 2-positive (HER2+) breast cancer with brain metastases (BM) and/or leptomeningeal disease (ROSET-BM). Median progression-free survival (PFS) was 14.6 months. Median overall survival (OS) was not reached (NR); 24-month OS rate was 56.0%. Subgroup analysis showed that median PFS was 13.2months in patients with analytical active BM, 17.5months in patients with leptomeningeal carcinomatosis (LMC), and NR in patients with analytical stable BM (24-month PFS rates in patients with analytical active BM, LMC, and analytical stable BM were 32.7%, 25.1%, and 60.8%, respectively). Median OS was 27.0months in patients with analytical active BM and NR in patients with LMC or analytical stable BM (24-month OS rates in patients with analytical active BM, LMC, and analytical stable BM were 52.0%, 61.6%, and 71.6%, respectively). The most common adverse event leading to discontinuation of T-DXd was interstitial lung disease (ILD; 23.1%); median ILD onset time among patients who discontinued T-DXd treatment due to ILD was 5.3 months. T-DXd has promising effectiveness in heavily pre-treated HER2+ metastatic breast cancer patients with BM and LMC. The incidence and median onset time of ILD were similar to those of Japanese subgroups in previous studies.