Randomized trial evaluates treatment durations and switching patterns of CDK4/6 inhibitors in HR+/HER2- metastatic breast cancer, suggesting varying outcomes among treatments.
Key Points
This study aims to assess treatment durations and switching patterns among patients with HR+/HER2- metastatic breast cancer receiving CDK4/6 inhibitors.
Selected adult patients from the Flatiron Health Research database who initiated first-line CDK4/6 inhibitors plus aromatase inhibitor from February 2015 to July 2024.
Utilized stabilized inverse probability of treatment weighting (sIPTW) to analyze treatment durations.
Kaplan-Meier analyses were performed to estimate treatment durations across different CDK4/6 inhibitor groups.
Treatment duration was longer for palbociclib (20.7 months) compared to ribociclib (18.3 months) and abemaciclib (17.1 months), with significant hazard ratios.
Discontinuation rates were higher for ribociclib (39.4%) and abemaciclib (41.1%) compared to palbociclib (33.3%).
Among patients initiating treatment from 2017 onward, a higher percentage received subsequent CDK4/6i-containing regimens, particularly among those originally treated with ribociclib or abemaciclib.