Selecting Between CDK4/6 Inhibitors and Navigating Delayed Initiation

Continuing with the first case, the faculty consider how to choose between abemaciclib and ribociclib for a patient who clearly meets monarchE eligibility, discussing the influence of longer follow-up and available survival data alongside comorbidities such as underlying gastrointestinal issues. The conversation then addresses how the timing of initiation factors into decision-making, revisiting the treatment windows permitted in the pivotal trials and acknowledging that these windows are broader than many clinicians assume. The panel explores how they would approach a patient who transfers into their practice or presents well beyond the trial-defined window, and where the point may lie at which the anticipated benefit no longer justifies initiating therapy. Clinical trial enrollment is raised as an alternative consideration for patients who fall outside established parameters. The segment concludes with practical guidance on monitoring frequency, laboratory assessment, and the additional clinical touchpoints these patients require to support tolerability and adherence.