3MO - Patient-reported outcomes (PROs) of Chinese patients (pts) in monarchE: Abemaciclib plus endocrine therapy (ET) in adjuvant treatment of HR+, HER2-, node-positive, high-risk, early breast cancer (EBC)

Background

Adjuvant abemaciclib (CDK4 & 6 inhibitor) plus ET demonstrated clinically meaningful improvement in invasive disease-free survival among Chinese pts with HR+, HER2-, node-positive, high-risk EBC in the monarchE phase III study. Here, we present data on PROs of Chinese pts at primary outcome analysis.

Methods

495 Chinese pts in safety population were included in PROs evaluation (abemaciclib + ET arm: 259; ET arm: 236). Health-related quality-of-life (FACT-B), ET symptoms (FACT-ES, 2 cognitive/3 bladder FACIT items), fatigue (FACIT-Fatigue) and symptom burden (FACT-B GP5) were assessed at randomization (baseline), 3/6/12/18/24 months on treatment and follow-up. Exploratory analyses assessed items reflecting common adverse events (AEs; diarrhea, fatigue, arthralgia, hot flushes), including frequency of scores for FACT-ES C5 “I have diarrhea”, and FACT-B GP5 “bothered by treatment side effect”. A mixed effect model for repeated measures (MMRM) compared summary and item scores by treatment arm. For the summary scores, a minimally important difference (MID) was defined as an effect size of a half standard deviation at baseline. For the item scores, a change of 1 was deemed meaningful.

Results

More than 90% of pts completed the baseline and at least one postbaseline PRO questionnaires. The MMRM analysis showed numerically similar results for all summary scores and items scores between two arms, and the changes from baseline, except diarrhea, did not reach MID in both arms at each visit. Change from baseline for diarrhea was ≤1.12 for pts receiving abemaciclib and ≤0 for ET only. From 3 months onwards, most pts who experienced diarrhea in the abemaciclib arm reported having diarrhea “a little bit” or “somewhat”. The frequency of diarrhea decreased after discontinuation of abemaciclib. Most pts in both arms reported being bothered “a little bit” or “not at all” by treatment side effect.

Conclusions

The addition of abemaciclib to ET did not result in notable differences in overall PROs, suggesting a tolerable profile for abemaciclib in Chinese EBC pts. Increased frequency of diarrhea was consistent with the known manageable, reversible AE profile.

Clinical trial identification

NCT03155997.

Editorial acknowledgement

Legal entity responsible for the study

Eli Lilly and Company.

Funding

Eli Lilly and Company.

Disclosure

Y. Yang, C. Qian: Financial Interests, Personal and Institutional, Full or part-time Employment: Eli Lilly and Company. All other authors have declared no conflicts of interest.