DESTINY-Breast05 and Post-Neoadjuvant HER2-Positive Early Breast Cancer

Dr. Jason Mouabbi discusses the design and patient population of DESTINY-Breast05 in the post-neoadjuvant setting for HER2-positive early breast cancer, highlighting key distinctions from the broader KATHERINE study population. He characterizes DESTINY-Breast05 as evaluating a higher-risk population, including patients with inoperable disease at baseline and patients who remained node-positive after neoadjuvant therapy. In contrast, KATHERINE enrolled a broader population of patients with residual invasive disease following neoadjuvant HER2-directed therapy. Dr. Mouabbi emphasizes that the eligibility criteria for DESTINY-Breast05 were more restrictive and that its findings should not simply be viewed as a complete replacement for KATHERINE. He reviews the trial's efficacy findings, noting the substantial improvement in invasive disease-free survival with T-DXd compared with T-DM1 at 3 years. The discussion then turns to the broader FDA indication for T-DXd in patients with residual invasive disease and the NCCN recommendation for patients at high risk of recurrence, with Dr. Rao emphasizing individualized risk-benefit assessment, including ILD considerations.