ERBB2 and breast cancer: For instance, T-DXd significantly improved progression-free survival (PFS) and overall survival (OS) in patients with HER2-low breast cancer in the DESTINY-Breast04 trial, extending median PFS from 5.1 to 9.9 months and OS from 16.8 to 23.4 months, with an objective response rate (ORR) of 52.6% [110].