HER-TEMPO - Real World Treatment-related Outcomes on T-DXd in Canada

This is a non-interventional, observational, hybrid (involving both primary and secondary data), cohort study that is utilizing patient support program (PSP) data. PSPs in Canada can support patients in accessing medicines after Health Canada has granted marketing authorization of a new drug or new indication before public reimbursement is available. The outcomes will be assessed for the HER2-positive and HER2-low cohorts separately. The primary objectives include assessing early treatment discontinuation rates at 3-, 6-, and 9-months after initiating T-DXd, and characterizing T-DXd dose modifications (i.e., interruptions and reductions) over the course of treatment for HER2+ mBC and HER2-low mBC. Secondary objectives include estimating the real-world time to discontinuation (rwTTD) of T-DXd, reasons for treatment discontinuations, and real world duration of treatment and dose intensity with T-DXd. The primary analysis population for all primary and secondary objectives will be the Total PSP Population (TPP), which includes all patients enrolled into the PSP who meet study criteria. Sensitivity analyses will also be performed in the Study PSP population (SPP), which will be a subset of patients from the TPP who provide study consent for additional data collection.