Prospective trials that include biomarker analyses are planned, including TRADE-DXd which evaluates T-DXd followed by Dato-DXd or vice versa (NCT06533826, aka Translational Breast Cancer Research Consortium TBCRC-064), SERIES which evaluates T-DXd after SG (NCT06263543), and ENCORE, a prospective registry study of sequential ADCs for HER2-negative MBC (NCT06774027, aka TBCRC-067). This evidence concerns the gene ERBB2 and breast carcinoma.