How do you reconcile data from the PATINA trial and DESTINY-Breast09 with respect to CDK4/6 inhibitor maintenance in metastatic ER+ HER2+ breast cancer?  

We don't have data on using T-DXd with palbociclib concurrently, but the data from DB09 and PATINA does lead to questions about the optimal 1st line approach in ER+HER2+ metastatic disease. DB09 allowed for concurrent endocrine therapy with T-DXd + P, and the ADC was continued until intolerance or p...