MONARCH 3

Podcasts, YouTube videos and X posts in our index that name this trial. A report screens them, searches for more and cites what clinicians said when it is built.

Official title

A Randomized, Double-Blind, Placebo-Controlled, Phase 3 Study of Nonsteroidal Aromatase Inhibitors (Anastrozole or Letrozole) Plus LY2835219, a CDK4/6 Inhibitor, or Placebo in Postmenopausal Women With Hormone Receptor-Positive, HER2-Negative Locoregionally Recurrent or Metastatic Breast Cancer With No Prior Systemic Therapy in This Disease Setting

Phase

Phase 3

Status

Active not recruiting

Conditions

Breast Cancer

Interventions

Abemaciclib; Anastrozole; Letrozole; Placebo

Arms

• Abemaciclib + NSAI · Experimental
• Placebo + NSAI · Placebo comparator

Enrollment

493

Primary outcomes

• Progression Free Survival (PFS)

Sponsor

Eli Lilly and Company

Start

Nov 6, 2014

Primary completion

Jan 31, 2017

Results posted

Yes

Registry record

NCT02246621 · updated Feb 3, 2026

• Goetz MP, Toi M, Campone M, Sohn J, Paluch-Shimon S, Huober J, Park IH, Tredan O, Chen SC, Manso L, Freedman OC, Garnica Jaliffe G, Forrester T, Frenzel M, Barriga S, Smith IC, Bourayou N, Di Leo A. MONARCH 3: Abemaciclib As Initial Therapy for Advanced Breast Cancer. J Clin Oncol. 2017 Nov 10;35(32):3638-3646. doi: 10.1200/JCO.2017.75.6155. Epub 2017 Oct 2. PubMed 28968163
• Johnston S, Martin M, Di Leo A, Im SA, Awada A, Forrester T, Frenzel M, Hardebeck MC, Cox J, Barriga S, Toi M, Iwata H, Goetz MP. MONARCH 3 final PFS: a randomized study of abemaciclib as initial therapy for advanced breast cancer. NPJ Breast Cancer. 2019 Jan 17;5:5. doi: 10.1038/s41523-018-0097-z. eCollection 2019. PubMed 30675515
• Hong J, Chen T, Ouyang L, Du N, Li A, Zhou Z, Zhang H, Xia Z, Meng J. Cost-effectiveness comparison of dalpiciclib and abemaciclib combined with an aromatase inhibitor as first-line treatment for HR+/HER2- advanced breast cancer. Expert Rev Pharmacoecon Outcomes Res. 2024 Apr;24(4):559-566. doi: 10.1080/14737167.2024.2330542. Epub 2024 Mar 20. PubMed 38470447
• Rugo HS, Harmer V, O'Shaughnessy J, Jhaveri K, Tolaney SM, Cardoso F, Bardia A, Maheshwari VK, Tripathi S, Haftchenary S, Pathak P, Fasching PA. Quality of life with ribociclib versus abemaciclib as first-line treatment of HR+/HER2- advanced breast cancer: a matching-adjusted indirect comparison. Ther Adv Med Oncol. 2023 Feb 24;15:17588359231152843. doi: 10.1177/17588359231152843. eCollection 2023. PubMed 36861085
• Takahashi M, Tokunaga E, Mori J, Tanizawa Y, van der Walt JS, Kawaguchi T, Goetz MP, Toi M. Japanese subgroup analysis of the phase 3 MONARCH 3 study of abemaciclib as initial therapy for patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer. Breast Cancer. 2022 Jan;29(1):174-184. doi: 10.1007/s12282-021-01295-0. Epub 2021 Oct 18. PubMed 34661821
• Goetz MP, Okera M, Wildiers H, Campone M, Grischke EM, Manso L, Andre VAM, Chouaki N, San Antonio B, Toi M, Sledge GW Jr. Safety and efficacy of abemaciclib plus endocrine therapy in older patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative advanced breast cancer: an age-specific subgroup analysis of MONARCH 2 and 3 trials. Breast Cancer Res Treat. 2021 Apr;186(2):417-428. doi: 10.1007/s10549-020-06029-y. Epub 2021 Jan 3. PubMed 33392835