Treatment With Adjuvant Abemaciclib Plus Endocrine Therapy in Patients With High-risk Early Breast Cancer Who Received Neoadjuvant Chemotherapy: A Prespecified Analysis of the monarchE Randomized Clinical Trial
- PMID: 35653145
- PMCID: PMC9164117
- DOI: 10.1001/jamaoncol.2022.1488
Treatment With Adjuvant Abemaciclib Plus Endocrine Therapy in Patients With High-risk Early Breast Cancer Who Received Neoadjuvant Chemotherapy: A Prespecified Analysis of the monarchE Randomized Clinical Trial
Abstract
Importance: Patients selected to receive neoadjuvant chemotherapy (NAC) are usually those at higher risk of relapse, and there is a need to find better therapeutic options for these patients.
Objective: To determine the efficacy and safety outcomes for patients with hormone receptor (HR)-positive, ERBB2 (formerly HER2)-, high-risk early breast cancer enrolled in the randomized clinical trial monarchE who received NAC.
Design, setting, and participants: The monarchE randomized clinical trial was a multicenter, phase 3, open-label study that evaluated adjuvant treatment with abemaciclib plus endocrine therapy (ET) compared with ET alone in patients with HR+, ERBB2-, and node-positive early breast cancer who were at high risk of recurrence. Patients were recruited between July 2017 and August 2019 from 603 sites in 38 countries. This subgroup analysis was performed with primary outcome data, with a cutoff date of July 8, 2020.
Intervention: Enrolled patients were randomized (1:1) to receive standard of care ET for at least 5 years with or without treatment with abemaciclib (150 mg, twice daily) for 2 years (treatment period) or until criteria were met for discontinuation.
Main outcomes and measures: Prior chemotherapy (NAC vs adjuvant vs none) was a stratification factor in monarchE, and and a prespecified exploratory analysis included outcomes in patients who received NAC. The data presented in this article are from the primary outcome analysis (395 invasive disease-free survival [IDFS] events; cutoff date, July 8, 2020; median follow-up 19 months [IQR, 15.6-23.9 months]). Invasive disease-free survival (the primary end point of monarchE) and distant relapse-free survival (DRFS) were evaluated using the Cox proportional hazard model and Kaplan-Meier method.
Results: Of the 5637 patients (mean [SD] age, 49.9 [10.6] years; 2046 women [99.5%]; 462 Asian [22.8%], 54 Black [2.7%], and 1473 White participants [70.8%]) enrolled in monarchE, 2056 (37%) received treatment with NAC. In this subgroup, treatment with abemaciclib and ET demonstrated clinically meaningful benefit in IDFS (hazard ratio, 0.61; 95% CI, 0.47-0.80) and DRFS (hazard ratio, 0.61; 95% CI, 0.46-0.81), which corresponded with an absolute improvement of 6.6% in 2-year IDFS rates and 6.7% in 2-year DRFS rates. A consistent treatment benefit was observed across subgroups of pathological breast tumor size or number of positive lymph nodes at surgery.
Conclusions and relevance: In the randomized clinical trial monarchE, treatment with adjuvant abemaciclib combined with ET demonstrated a clinically meaningful improvement in IDFS and DRFS for patients with HR+, ERBB2-, node-positive, high-risk early breast cancer who received NAC before trial enrollment.
Trial registration: ClinicalTrials.gov Identifier: NCT03155997.
Conflict of interest statement
Figures

Comment in
-
Quantifying Clinical Utility of Adjuvant Abemaciclib in Patients With High-risk Early Breast Cancer Who Received Neoadjuvant Chemotherapy.JAMA Oncol. 2022 Nov 1;8(11):1701. doi: 10.1001/jamaoncol.2022.4528. JAMA Oncol. 2022. PMID: 36173642 No abstract available.
Similar articles
-
Adjuvant abemaciclib combined with endocrine therapy for high-risk early breast cancer: updated efficacy and Ki-67 analysis from the monarchE study.Ann Oncol. 2021 Dec;32(12):1571-1581. doi: 10.1016/j.annonc.2021.09.015. Epub 2021 Oct 14. Ann Oncol. 2021. PMID: 34656740 Clinical Trial.
-
Abemaciclib plus endocrine therapy for hormone receptor-positive, HER2-negative, node-positive, high-risk early breast cancer (monarchE): results from a preplanned interim analysis of a randomised, open-label, phase 3 trial.Lancet Oncol. 2023 Jan;24(1):77-90. doi: 10.1016/S1470-2045(22)00694-5. Epub 2022 Dec 6. Lancet Oncol. 2023. PMID: 36493792 Free PMC article. Clinical Trial.
-
Abemaciclib Combined With Endocrine Therapy for the Adjuvant Treatment of HR+, HER2-, Node-Positive, High-Risk, Early Breast Cancer (monarchE).J Clin Oncol. 2020 Dec 1;38(34):3987-3998. doi: 10.1200/JCO.20.02514. Epub 2020 Sep 20. J Clin Oncol. 2020. PMID: 32954927 Free PMC article. Clinical Trial.
-
Long-term outcomes of high-risk HR-positive and HER2-negative early breast cancer patients from GEICAM adjuvant studies and El Álamo IV registry.Breast Cancer Res Treat. 2023 Sep;201(2):151-159. doi: 10.1007/s10549-023-07002-1. Epub 2023 Jun 20. Breast Cancer Res Treat. 2023. PMID: 37338729 Free PMC article. Review.
-
Role of abemaciclib in primary breast cancer: a narrative review of MonarchE.Transl Breast Cancer Res. 2022 Jan 31;3:3. doi: 10.21037/tbcr-21-27. eCollection 2022. Transl Breast Cancer Res. 2022. PMID: 38751527 Free PMC article. Review.
Cited by
-
Arbeitsgemeinschaft Gynäkologische Onkologie Recommendations for the Diagnosis and Treatment of Patients with Early Breast Cancer: Update 2023.Breast Care (Basel). 2023 Aug;18(4):289-305. doi: 10.1159/000531578. Epub 2023 Jun 16. Breast Care (Basel). 2023. PMID: 37900552 Free PMC article. Review.
-
Optimizing treatment sequence for inoperable locally advanced breast cancer: Long-term outcomes of surgery first versus neoadjuvant chemotherapy in a real-world setting.Int J Cancer. 2025 Jan 15;156(2):368-378. doi: 10.1002/ijc.35140. Epub 2024 Aug 23. Int J Cancer. 2025. PMID: 39177486 Free PMC article.
-
Abemaciclib: A Review in Early Breast Cancer with a High Risk of Recurrence.Target Oncol. 2023 Mar;18(2):287-294. doi: 10.1007/s11523-023-00952-y. Epub 2023 Feb 24. Target Oncol. 2023. PMID: 36826463 Review.
-
Implications of inflammatory cell death-related IFNG and co-expressed RNAs (AC006369.1 and CCR7) in breast carcinoma prognosis, and anti-tumor immunity.Front Genet. 2023 Jun 20;14:1112251. doi: 10.3389/fgene.2023.1112251. eCollection 2023. Front Genet. 2023. PMID: 37408777 Free PMC article.
-
Extended Adjuvant Endocrine Therapy in Early Breast Cancer Patients-Review and Perspectives.Cancers (Basel). 2023 Aug 21;15(16):4190. doi: 10.3390/cancers15164190. Cancers (Basel). 2023. PMID: 37627218 Free PMC article. Review.
References
-
- National Comprehensive Cancer Network . NCCN clinical practice guidelines in oncology: breast cancer, version 5.2020. Accessed September 3, 2021. https://www2.tri-kobe.org/nccn/guideline/breast/english/breast.pdf - PubMed
Publication types
MeSH terms
Substances
Associated data
LinkOut - more resources
Full Text Sources
Medical
Research Materials
Miscellaneous