Impact of dose reductions on adjuvant abemaciclib efficacy for patients with high-risk early breast cancer: analyses from the monarchE study

The monarchE trial—which showed significantly improved invasive disease-free survival and distant relapse-free survival for patients with node-positive, HR+ HER2-, high-risk early breast cancer who were treated with adjuvant abemaciclib—allowed for abemaciclib dose reductions to proactively manage adverse events. Now in an exploratory analysis, researchers investigated the effects of these dose reductions on adjuvant abemaciclib’s efficacy. The data showed that the estimated 4-year invasive disease-free survival rates were generally consistent among the dose-intensity subgroups, suggesting that that the efficacy of adjuvant abemaciclib was not compromised by protocol-mandated dose reductions for this patient group.