T-DXd and T-DM1 Selection in HER2-Positive Early Breast Cance

Dr. Jason Mouabbi discusses the evolving roles of T-DXd and T-DM1 in the post-neoadjuvant management of HER2-positive early breast cancer following the DESTINY-Breast05 findings. He emphasizes that patients who receive the DESTINY-Breast11 regimen and subsequently have residual disease represent an important clinical scenario, as the optimal post-neoadjuvant treatment approach continues to evolve. Dr. Mouabbi highlights T-DM1 as a potential option for patients who have already received T-DXd or who have lower-volume residual disease that was outside the DESTINY-Breast05 eligibility population. He also considers patient-specific factors that may influence T-DXd selection, particularly factors associated with increased risk of interstitial lung disease, including baseline renal impairment and chronic pulmonary comorbidities. A prior history of ILD is identified as an important consideration against T-DXd use. The discussion underscores that, although T-DXd has demonstrated strong efficacy in high-risk disease, treatment selection in HER2-positive early breast cancer should continue to incorporate individual recurrence risk, prior therapy, eligibility, and safety considerations.