T-DM1 Combined With CDK4/6 Inhibitor Ribociclib

Patients with advanced breast cancer with at least one evaluable lesion and histologically proven invasive breast cancer were eligible for inclusion. Histopathologically positive for HER2 (IHC 3+, or IHC 2+ with fluorescence in situ hybridization (FISH) positive, either primary or metastatic. Patients with advanced breast cancer must have previously received first-line therapy or initial rescue therapy and have been treated with trastuzumab against HER2.