399P Optimizing post-CDK4/6i strategies in HR+/HER2− metastatic breast cancer: A network meta-analysis of emerging therapies

Optimal treatment sequencing for HR+/HER2− metastatic breast cancer (MBC) after the progression of CDK4/6 inhibitors (CDK4/6i) remains unclear. We conducted a systematic review and network meta-analysis (NMA) to compare the efficacy of antibody-drug conjugates (ADCs), PI3K/AKT/mTOR inhibitors, selective estrogen receptor degraders (SERDs), and continued CDK4/6 inhibitors.