Oops, you're using an old version of your browser so some of the features on this page may not be displaying properly.

MINIMAL Requirements: Google Chrome 24+Mozilla Firefox 20+Internet Explorer 11Opera 15–18Apple Safari 7SeaMonkey 2.15-2.23

Presidential Symposium II

2048 - MONARCH 3: Abemaciclib as initial therapy for patients with HR+/HER2- advanced breast cancer


10 Sep 2017


Presidential Symposium II


Cytotoxic Therapy;  Breast Cancer


Angelo di Leo


Annals of Oncology (2017) 28 (suppl_5): v605-v649. 10.1093/annonc/mdx440


A. di Leo1, M. Toi2, M. Campone3, J. Sohn4, S. Paluch-Shimon5, J. Huober6, I.H. Park7, O. Tredan8, S. Chen9, L. Manso10, O. Freedman11, G.G. Jaliffe12, T. Forrester13, M. Frenzel13, S. Barriga14, I.C. Smith15, N. Bourayou16, M.P. Goetz17

Author affiliations

  • 1 Sandro Pitigliani Medical Oncology Department, Nuovo Ospedale di Prato S. Stefano - Istituto Toscano Tumori, 59100 - Prato/IT
  • 2 Department Of Surgery Graduate School Of Medicine, Kyoto University, 606-8507 - Kyoto/JP
  • 3 Medical Oncology, Institut de Cancerologie de l'Ouest René Gauducheau, Bd Jacques Monod, 44805 - Saint-Herblain/FR
  • 4 Internal Medicine, Severance Hospital, Yonsei Cancer Center, 120-752 - Seoul/KR
  • 5 Division Of Oncology, Sheba Medical Center, 52621 - Ramat Gan/IL
  • 6 Breast Center, Department Of Gynecology, University of Ulm, Ulm/DE
  • 7 Center For Breast Cancer, National Cancer Center, 10408 - Goyangsi/KR
  • 8 Rhone, Centre Léon Bérard, 69130 - Lyon/FR
  • 9 Gs, Chang Gung Memorial Hospital-Linkou, 333 - Taoyuan City/TW
  • 10 Clinical Oncologist, Hospital Universitario 12 de Octubre, 28041 - Madrid/ES
  • 11 Oncology, R.S. McLaughlin Durham Regional Cancer Centre, Oshawa/CA
  • 12 Medical Oncology, Grupo Médico CAMINO S.C., Mexico City/MX
  • 13 Global Statistical Sciences, Eli Lilly and Company, Indianapolis/US
  • 14 Oncology Clinical Development, Eli Lilly and Company, Madrid/ES
  • 15 Oncology Clinical Development, Eli Lilly and Company, Indianapolis/US
  • 16 Oncology Clinical Development, Eli Lilly and Company, Paris/FR
  • 17 Oncology, Mayo Clinic, Rochester/US


Login to access the resources on OncologyPRO.

If you do not have an ESMO account, please create one for free.

Abstract 2048


Abemaciclib is an oral selective CDK4 & 6 inhibitor dosed on a continuous schedule and has demonstrated efficacy and tolerability as monotherapy and in combination with fulvestrant in patients (pts) with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC). MONARCH 3 evaluates abemaciclib plus the non-steroidal aromatase inhibitors (NSAI) anastrozole (A) or letrozole (L) as initial therapy in HR+/HER2- ABC.


MONARCH 3 is a double-blind, Phase 3 study of abemaciclib + NSAI (A or L) vs placebo (P) + NSAI in postmenopausal women with HR+/HER2- ABC who have had no prior systemic therapy in the metastatic setting. Endocrine naïve pts or pts with disease relapse >12 months after (neo)adjuvant endocrine therapy (ET) were randomized 2:1 and stratified by metastatic site (visceral, bone only, or other) and prior ET (AI vs no ET vs other). Pts received abemaciclib/P (150 mg, twice daily continuous schedule) + 1 mg A or 2.5 mg L, daily. The primary objective was investigator-assessed progression-free survival (PFS). Secondary objectives included objective response rate (ORR) and safety. The study was powered to 80% at 1-sided α=.025 assuming a hazard ratio (HR) of 0.67 in favor of abemaciclib + NSAI, with analyses at 189 and 240 PFS events.


493 women were randomized to abemaciclib + NSAI (n = 328) or P + NSAI (n = 165). Pt characteristics were: visceral disease (52.9%), measurable disease (80.5%), prior (neo)adjuvant AI (27.4%), and de novo ABC (39.8%). At the interim analysis, 194 PFS events were observed. The PFS was significantly prolonged with a HR of 0.543 (95% CI, 0.409 to 0.723, P=.000021; median PFS: not reached in abemaciclib arm, 14.7 months in placebo arm). In pts with measurable disease, the ORR was 59% in the abemaciclib arm and 44% in the P arm (P=.004). The most frequent adverse events were (abemaciclib vs P arms) diarrhea (81.3% [grade 3: 9.5%, no grade 4] vs 29.8% [grade 3: 1.2%, no grade 4]), neutropenia (41.3% [grade 3/4: 21.1%] vs 1.9% [grade 3/4: 1.2%]), and fatigue (40.1% [grade 3: 1.8%] vs 31.7% [grade 3: 0%]).


Abemaciclib + NSAI demonstrated a tolerable safety profile and was an effective initial treatment for pts with HR+/HER2- ABC, significantly improving PFS and ORR.

Clinical trial identification


Legal entity responsible for the study

Eli Lilly and Company


Eli Lilly and Company


A. Di Leo: Honoraria, consulting, and travel funds: Daichii-Sankyo, Roche, Novartis, Pfizer, AstraZeneca, Genomic Health, Eisai, Lilly, Pierre Fabre, Bayer, Celgene. Consulting and travel funds: Puma Biotechnology. Research funds: Novartis, Pfizer, AstraZeneca. M. Campone: Honoraria, Consulting/advisory, Speakers’ bureau: Novartis, Pfizer, AstraZeneca; Lilly. Travel funds: Novartis, AstraZeneca. J. Sohn: Research Funding: AstraZeneca, Eli Lilly and Company, Novartis, Genentech, Pfizer, MSD Oncology. S. Paluch-Shimon: Consulting/advisory, Speakers’ Bureau: Pfizer, Novartis, Roche, AstraZeneca. J. Huober: Honoraria, Consulting/advisory, Travel funds: Novartis, Pfizer, Roche. Honoraria, Consulting: Lilly. O. Tredan: Honoraria, Consulting/Advisory, Travel funds: Lilly, Roche, Novartis, AstraZeneca, Pfizer, Celldex. G.G. Jaliffe: Speakers’ Bureau: Roche, Amgen. T. Forrester, M. Frenzel, I.C. Smith, N. Bourayou: Employment and Stock Ownership: Eli Lilly and Company. S. Barriga: Employment: Eli Lilly and Company. M.P. Goetz: Consulting/Advisory: Eli Lilly and Company, Biotheranostics. Research funding: Eli Lilly and Company. All other authors have declared no conflicts of interest.

This site uses cookies. Some of these cookies are essential, while others help us improve your experience by providing insights into how the site is being used.

For more detailed information on the cookies we use, please check our Privacy Policy.

Customise settings
  • Necessary cookies enable core functionality. The website cannot function properly without these cookies, and you can only disable them by changing your browser preferences.