Long-term Patient-reported Outcomes from monarchE: Abemaciclib plus Endocrine Therapy for Adjuvant HR+, HER2-, Node-positive, High-risk, Early Breast Cancer

초록

Background: Abemaciclib demonstrated sustained benefit in invasive disease-free survival and a tolerable safety profile in monarchE at 42 months (mo) median follow-up (mFU). At 19mo mFU initial patient (pt)-reported outcome (PRO) findings supported a tolerable profile with most remaining on treatment (tx). With all pts now off abemaciclib, we report data including the full 2 year tx period and follow-up to evaluate long-term impact on PROs. Methods: Pts completed PROs (FACT-B, FACT-ES, FACIT-Fatigue) at baseline, 3, 6, 12, 18, 24mo and 1, 6, 12mo after tx discontinuation (dc). Mixed effects repeated measures model estimated changes from baseline within and between arms for summary scores and individual items. Meaningful change was 0.5 standard deviation of baseline summary scores and 1 point for individual items. Additional analyses: frequencies of responses to items associated with adverse events (AEs; eg, diarrhea, fatigue) and tx bother. Result: PRO completion rates (5591 treated pts) were >90% on tx and ~80% during follow-up. Within- and between-arms, differences in mean changes from baseline for all PROs were less than prespecified thresholds for meaningful difference, except for diarrhea, with worse scores in abemaciclib+ET at 3 and 6mo. During tx most pts reported being bothered “a little bit” or “not at all” by side effects in both arms and most pts (79-85%) on abemaciclib reported “not at all” to “somewhat” for diarrhea. PROs in both arms (post-tx follow-up) were similar to baseline, with ≥80% of pts on abemaciclib arm reporting “not at all” for diarrhea. Discussion: Adjuvant abemaciclib added to ET did not result in meaningful differences in PROs, except for diarrhea, which is considered clinically manageable. Conclusion: Long-term findings suggest reversibility of these effects after tx dc and can help inform pt risk/benefit assessment.