ERBB2 and breast cancer: At the 2024 ASCO Annual Meeting, the DB-06 study (NCT04494425) results were presented, showing that T-DXd significantly improved median PFS in patients with HER2-low (IHC 1+-2+/ISH-) and HER2-ultralow (0+<IHC<1+) advanced breast cancer compared to TPC, with a median PFS of 13.2 months for both groups.