Effect of prior treatments on post-CDK4/6 inhibitor survival in HR-positive HER2-negative metastatic breast cancer

Multiple treatment options exist for patients with metastatic breast cancer (mBC); however, limited information is available on the impact of prior treatments on survival outcomes for novel therapies, such as CDK 4/6 inhibitors for HR-positive, HER2-negative mBC. Analysis of the Flatiron Health database found that prior treatment duration and class are associated with decreased overall survival after CDK 4/6 inhibitor administration. The authors conclude that this highlights the importance for clinicians to consider prior treatment and duration in treatment decision-making, and for trialists to stratify by these factors when randomizing patients or reporting results.