NCT04108858 2025-10-01Testing the Addition of an Anti-cancer Drug, Copanlisib, to the Usual Maintenance Treatment (Trastuzumab and Pertuzumab) After Initial Chemotherapy in a Phase Ib/II Trial for Advanced HER2 Positive Breast CancerNational Cancer Institute (NCI)Phase 1/2 Terminated2 enrolled 6 charts