Abemaciclib (LY2835219) Plus Fulvestrant Compared to Placebo Plus Fulvestrant in Previously Treated Breast Cancer
postMONARCH
postMONARCH: A Randomized, Double Blind, Placebo-Controlled, Phase 3 Study to Compare the Efficacy of Abemaciclib Plus Fulvestrant to Placebo Plus Fulvestrant in Participants With HR+, HER2-, Advanced or Metastatic Breast Cancer Following Progression on a CDK4 & 6 Inhibitor and Endocrine Therapy
4 other identifiers
interventional
368
17 countries
138
Brief Summary
This study will evaluate the effect of adding abemaciclib to fulvestrant for the treatment of hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) breast cancer that progressed or recurred after previous treatment with a type of drug known as a CDK4/6 inhibitor and endocrine therapy. Participation could last up to 5 years, depending on how you and your tumor respond.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P50-P75 for phase_3
Started Mar 2022
Longer than P75 for phase_3
138 active sites
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
Click on a node to explore related trials.
Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
December 22, 2021
CompletedFirst Posted
Study publicly available on registry
December 27, 2021
CompletedStudy Start
First participant enrolled
March 11, 2022
CompletedPrimary Completion
Last participant's last visit for primary outcome
February 8, 2024
CompletedResults Posted
Study results publicly available
February 27, 2025
CompletedStudy Completion
Last participant's last visit for all outcomes
December 1, 2027
ExpectedJanuary 16, 2026
December 1, 2025
1.9 years
December 22, 2021
February 7, 2025
December 24, 2025
Conditions
Outcome Measures
Primary Outcomes (1)
Progression-Free Survival (PFS)
PFS defined as the time from the date of randomization to the first evidence of disease progression as defined by response evaluation criteria in solid tumors (RECIST) v1.1 or death from any cause. Progressive Disease (PD) was at least a 20% increase in the sum of the diameters of target lesions, with reference being the smallest sum on study and an absolute increase of at least 5 mm, or unequivocal progression of non-target lesions, or 1 or more new lesions. If a participant does not have a complete baseline disease assessment, then the PFS time was censored at the date of randomization, regardless of whether or not objectively determined disease progression or death has been observed for the participant. If a participant was not known to have died or have objective progression as of the data inclusion cutoff date for the analysis, the PFS time was censored at the last adequate tumor assessment date.
Randomization to the date of first documented progression of disease or death from any cause (Up to 21 Months)
Secondary Outcomes (2)
Progression Free Survival (PFS) Determined by Blinded Independent Central Review (BICR)
Randomization to the date of first documented progression of disease or death from any cause (Up to 22 Months)
Objective Response Rate (ORR): Percentage of Participants Who Achieved a Best Overall Response (BOR) of Complete Response (CR) or Partial Response (PR)
Randomization until measured progressive disease (Up to 22 Months)
Study Arms (2)
Arm A: Abemaciclib plus Fulvestrant
EXPERIMENTALAbemaciclib 150 milligram (mg) administered orally twice daily (BID) on Days 1 to 28 of a 28-day cycle in combination with fulvestrant 500 mg administered intramuscularly (IM) on Days 1 and 15 of Cycle 1, then on Day 1 of Cycle 2 and beyond. Participants received treatment until discontinuation criteria were met.
Arm B: Placebo plus Fulvestrant
ACTIVE COMPARATORPlacebo administered orally BID on Days 1 to 28 of a 28-day cycle in combination with fulvestrant 500 mg administered IM on Days 1 and 15 of Cycle 1, then on Day 1 of Cycle 2 and beyond. Participants received treatment until discontinuation criteria were met.
Interventions
Eligibility Criteria
You may qualify if:
- Have a diagnosis of HR+, HER2- locally advanced or metastatic breast cancer
- Have radiologic evidence of disease progression or recurrence either
- On treatment with a CDK4/6 inhibitor with aromatase inhibitor (AI) as initial therapy for advanced disease, or
- On/after treatment with a CDK4/6 inhibitor plus endocrine therapy (ET) administered as adjuvant therapy for early stage breast cancer
- Must be deemed appropriate for treatment with ET
- If female, have a postmenopausal status by natural or surgical means or by ovarian function suppression
- Have Response Evaluable Criteria in Solid Tumors (RECIST) evaluable disease (measurable disease and/or nonmeasurable disease)
- Have a performance status of 0 or 1 on the Eastern Cooperative Oncology Group scale (Oken et al. 1982)
- Have adequate renal, hematologic, and hepatic organ function
- Must be able to swallow capsules/tablets
You may not qualify if:
- Have visceral crisis, lymphangitic spread, or leptomeningeal carcinomatosis
- Have symptomatic or untreated central nervous system metastasis
- Have received any systemic therapy between disease recurrence/progression and study screening
- Have received more than 1 line of therapy for advanced or metastatic disease.
- Have received prior chemotherapy for metastatic breast cancer (MBC)
- Have received prior treatment with fulvestrant, any investigational estrogen receptor (ER)-directed therapy (including selective ER degraders \[SERDs\] and non-SERDs), any phosphatidylinositol 3-kinase (PI3K)-, mammalian target of rapamycin (mTOR)-, or protein kinase B (AKT)-inhibitor
Contact the study team to confirm eligibility.
Sponsors & Collaborators
Study Sites (138)
St. Joseph's Hospital and Medical Center
Phoenix, Arizona, 85004, United States
Highlands Oncology Group
Springdale, Arkansas, 72762, United States
Providence Medical Foundation
Fullerton, California, 92835, United States
Cancer and Blood Specialty Clinic
Los Alamitos, California, 90720, United States
TRIO-US (Translational Research in Oncology-US)
Los Angeles, California, 90024, United States
Keck School of Medicine of USC
Los Angeles, California, 90033, United States
UCLA Hematology/Oncology - Parkside
Santa Monica, California, 90404, United States
Olive View-UCLA Medical Center
Sylmar, California, 91342, United States
Torrance Memorial Physician Network / Cancer Care
Torrance, California, 90505, United States
PIH Health Hematology Medical Oncology
Whittier, California, 90602, United States
Rocky Mountain Cancer Center - Hale Parkway
Denver, Colorado, 80220, United States
Florida Cancer Specialists SOUTH/Sarah Cannon Research Institute/SCRI
Fort Myers, Florida, 33901-8101, United States
Millennium Oncology Research Clinic
Hollywood, Florida, 33024, United States
University of Miami Hospital and Clinics, Sylvester Cancer Center
Miami, Florida, 33136, United States
Woodlands Medical Specialists, PA
Pensacola, Florida, 32503, United States
Florida Cancer Specialists SOUTH/Sarah Cannon Research Institute/SCRI
Sarasota, Florida, 34232, United States
Florida Cancer Specialists EAST/Sarah Cannon Research Institute/SCRI
West Palm Beach, Florida, 33401, United States
Winship Cancer Institute, Emory University
Atlanta, Georgia, 30322, United States
Northeast Georgia Medical Center
Gainesville, Georgia, 30501, United States
Central Georgia Cancer Care
Macon, Georgia, 31201, United States
Kapiolani Medical Center for Women and Children
Honolulu, Hawaii, 96826, United States
Ingalls Memorial Hospital
Harvey, Illinois, 60426, United States
Hematology Oncology Clinic- Baton Rouge/Sarah Cannon Research Institute/SCRI
Baton Rouge, Louisiana, 70809, United States
Clinical Trials of SWLA
Lake Charles, Louisiana, 70601, United States
Central Maine Medical Center
Lewiston, Maine, 04240, United States
Mfsmc-Hjwci
Baltimore, Maryland, 21237, United States
Maryland Oncology Hematology, P.A. - Clinton
Clinton, Maryland, 20735, United States
Massachusetts General Hospital
Boston, Massachusetts, 02114, United States
Dana Farber Cancer Institute
Boston, Massachusetts, 02215, United States
MGH Northshore Cancer Center
Danvers, Massachusetts, 01923, United States
Southcoast Centers for Cancer Care
Fairhaven, Massachusetts, 02719, United States
Dana-Farber Cancer Institute - Foxborough
Foxborough, Massachusetts, 02035, United States
Dana Farber Cancer Center Merrimack Valley
Methuen, Massachusetts, 01844, United States
Dana Farber Cancer Institute
Milford, Massachusetts, 01757, United States
Mass General Cancer Center
Newton, Massachusetts, 02462, United States
Dana Farber Cancer Institute
South Weymouth, Massachusetts, 02190, United States
Reliant Medical Group
Worcester, Massachusetts, 01606, United States
St. Vincent Frontier Cancer Center
Billings, Montana, 59102, United States
Dana Farber Cancer Center Londonderry
Londonderry, New Hampshire, 03053, United States
University of New Mexico Comprehensive Cancer Center
Albuquerque, New Mexico, 87106, United States
Lifespan Cancer Institute
Providence, Rhode Island, 02906, United States
Tennessee Oncology-Chattanooga /Sarah Cannon Research Institute/SCRI
Chattanooga, Tennessee, 37404, United States
Sarah Cannon Research Institute/SCRI
Nashville, Tennessee, 37203, United States
Tennessee Oncology-Nashville/Sarah Cannon Research Institute/SCRI
Nashville, Tennessee, 37203, United States
Texas Oncology - Bedford
Bedford, Texas, 76022, United States
Texas Oncology - Denton
Denton, Texas, 76201, United States
Texas Oncology, P.A.
El Paso, Texas, 79902, United States
University of Texas MD Anderson Cancer Center
Houston, Texas, 77030-4009, United States
Texas Oncology - McKinney
McKinney, Texas, 75071, United States
Woodlands Medical Specialists, PA
McKinney, Texas, 75071, United States
Woodlands Medical Specialists, PA
Mesquite, Texas, 75150, United States
Texas Oncology - Plano East
Plano, Texas, 75075-7787, United States
Texas Oncology-Plano West
Plano, Texas, 75093, United States
Mays Cancer Center
San Antonio, Texas, 78229, United States
US Oncology
The Woodlands, Texas, 77380, United States
Texas Oncology - Tyler Cancer Center
Tyler, Texas, 75702, United States
Intermountain Medical Center
Murray, Utah, 84107, United States
Intermountain Healthcare - St. George
St. George, Utah, 84790, United States
The University of Vermont Medical Center Inc.
Burlington, Vermont, 05401, United States
Shenandoah Oncology, P.C.
Winchester, Virginia, 22601, United States
Fundación Cenit Para La Investigación En Neurociencias
CABA, Buenos Aires F.D., 1125, Argentina
Fundación Respirar
Buenos Aires, Buenos Air, C1426ABP, Argentina
Centro de Investigaciones Metabólicas (CINME)
Ciudad Autónoma de Buenos Aire, Buenos Air, C1027AAP, Argentina
Instituto Médico Río Cuarto
Río Cuarto, Córdoba Province, 5800, Argentina
Centro Medico San Roque
San Miguel de Tucumán, Tucumán Province, 4000, Argentina
CER San Juan
San Juan, 5400, Argentina
Algemeen Ziekenhuis klina
Brasschaat, Antwerpen, 2930, Belgium
Jessa Ziekenhuis
Hasselt, Limburg, 3500, Belgium
CHU UCL Namur/Site Sainte Elisabeth
Namur, 5000, Belgium
Multiscan
Pardubice, Pardubický kraj, 53203, Czechia
Fakultni nemocnice Hradec Kralove
Hradec Králové, 500 05, Czechia
Herlev and Gentofte Hospital
Copenhagen, Capital Region, 2730, Denmark
Regionshospitalet Gødstrup
Herning, Central Jutland, 7400, Denmark
Institut Bergonié - Centre Régional de Lutte Contre Le Cancer de Bordeaux et Sud Ouest
Bordeaux, Aquitaine, 33076, France
CHRU de Brest
Brest, Finistère, 29609, France
Hôpital privé du Confluent SAS
Nantes, Loire-Atlantique, 44277, France
CHD Vendee
La Roche-sur-Yon, Vendée, 85000, France
University Hospital of Patras
Pátrai, Achaḯa, 26504, Greece
Alexandra Hospital
Athens, Attikí, 115 28, Greece
University General Hospital of Heraklion
Heraklion, Irakleío, 711 10, Greece
Euromedica General Clinic of Thessaloniki
Thessaloniki, 546 45, Greece
Bacs-Kiskun Megyei Korhaz
Kecskemét, Bács-Kiskun county, 6000, Hungary
Petz Aladar Egyetemi Oktato Korhaz
Győr, Győr-Moson-Sopron, 9024, Hungary
Magyar Honvedseg Egeszsegugyi Kozpont
Budapest, 1062, Hungary
Országos Onkológiai Intézet
Budapest, 1122, Hungary
Meir Medical Center
Kfar Saba, Central District, 4428164, Israel
Rabin Medical Center
Petah Tikva, Central District, Israel
Sheba Medical Center
Ramat Gan, Central District, 5265601, Israel
Hadassah Medical Center
Jerusalem, Jerusalem, 9112001, Israel
Soroka Medical Center
Beersheba, Southern District, 8400000, Israel
Sourasky Medical Center
Tel Aviv, Tell Abīb, 6423906, Israel
Humanitas Istituto Clinico Catanese
Misterbianco, Catania, 95045, Italy
IRCCS - Istituto Romagnolo per lo Studio dei Tumori (IRST) "Dino Amadori"
Meldola, Emilia-Romagna, 47014, Italy
P.O. "S. Maria della Misericordia" Azienda Sanitaria Universitaria Friuli Centrale
Udine, Friuli Venezia Giulia, 33100, Italy
Instituto Tumori Giovanni Paolo II
Bari, 70124, Italy
Ospedale Misericordia di Grosseto
Grosseto, 58100, Italy
Ospedale San Raffaele
Milan, 20132, Italy
ASL Viterbo Ospedale Belcolle
Viterbo, 01100, Italy
Centro de Investigacion en Artritis y Osteoporosis SC
Mexicali, Estado de Baja California, 21200, Mexico
COI Tijuana - Centro Oncológico Internacional
Tijuana, Estado de Baja California, 22010, Mexico
Centro Oncológico Internacional (COI)
Guadalajara, Jalisco, 45647, Mexico
Centro Regiomontano de Investigación
Monterrey, Nuevo León, 64060, Mexico
Oncologico Potosino, S.C.
San Luis Potosí City, San Luis Potosí, 78209, Mexico
Europejskie Centrum Zdrowia - Oddzial Onkologii
Otwock, Masovian Voivodeship, 05-400, Poland
Opolskie Centrum Onkologii w Opolu im. prof. Tadeusza Koszarowskiego
Opole, Opole Voivodeship, 45-060, Poland
Seoul National University Bundang Hospital
Seongnam, Kyǒnggi-do, 13620, South Korea
Korea University Anam Hospital
Seoul, Seoul-teukbyeolsi [Seoul], 02841, South Korea
Korea University Guro Hospital
Seoul, Seoul-teukbyeolsi [Seoul], 08308, South Korea
Kyungpook National University Chilgok Hospital
Daegu, Taegu-Kwangyǒkshi, 41404, South Korea
CHUAC-Hospital Teresa Herrera
A Coruña, A Coruña [La Coruña], 15006, Spain
Hospital Universitari Son Espases
Palma, Balears [Baleares], 07120, Spain
Parc de Salut Mar - Hospital del Mar
Barcelona, Barcelona [Barcelona], 08003, Spain
Hospital Clínic de Barcelona
Barcelona, Catalunya [Cataluña], 08036, Spain
Hospital Clínico Universitario Virgen de la Arrixaca
El Palmar, Murcia, Región de, 30120, Spain
H.R.U Málaga - Hospital Materno-infantil
Málaga, Málaga, 29011, Spain
Complejo Hospitalario de Navarra
Pamplona, Navarre, 31009, Spain
Hospital Universitari Sant Joan de Reus
Reus, Tarragona [Tarragona], 43204, Spain
Hospital Universitario Doctor Peset
Valencia, Valenciana, Comunitat, 46017, Spain
Hospital Infanta Cristina
Badajoz, 06006, Spain
Hospital General Universitario Gregorio Marañon
Madrid, 28009, Spain
Hospital Universitario de Toledo
Toledo, 45007, Spain
Karolinska Universitetssjukhuset Solna
Stockholm, Stockholms, 171 76, Sweden
Universitetssjukhuset Örebro
Örebro, Örebro Län [se-18], 701 85, Sweden
Chi Mei Medical Center
Tainan, Tainan, 71004, Taiwan
Kaohsiung Medical University Hospital
Kaohsiung City, 80756, Taiwan
Taipei Tzu Chi General Hospital
New Taipei City, 231, Taiwan
Mackay Memorial Hospital
Taipei, 10449, Taiwan
Taipei Veterans General Hospital
Taipei, 11217, Taiwan
Chang Gung Medical Foundation-Linkou Branch
Taoyuan District, 333, Taiwan
Izmir Medical Park Hospital
Cordaleo, İzmir, 009035575, Turkey (Türkiye)
Necmettin Erbakan Meram Medical Fac.
Meram, Konya, 42080, Turkey (Türkiye)
Adana City Hospital
Adana, 01370, Turkey (Türkiye)
Ankara Gülhane Eitim ve Aratrma Hastanesi
Ankara, 06010, Turkey (Türkiye)
Memorial Ankara Hastanesi
Ankara, 06520, Turkey (Türkiye)
Dicle Üniversitesi
Diyarbakır, 21200, Turkey (Türkiye)
Trakya University
Edirne, 22030, Turkey (Türkiye)
TC Saglik Bakanligi Goztepe Prof. Dr. Suleyman Yalcin Sehir Hastanesi
Istanbul, 34722, Turkey (Türkiye)
İnönü Üniversitesi Turgut Özal Tıp Merkezi Eğitim ve Araştırma Hastanesi
Malatya, 44280, Turkey (Türkiye)
Related Publications (2)
Zapatero-Solana E, Ding Y, Pulliam N, de Dios A, Ortiz-Ruiz MJ, Lallena MJ. Models of Early Resistance to CDK4/6 Inhibitors Unveil Potential Therapeutic Treatment Sequencing. Int J Mol Sci. 2025 Mar 14;26(6):2643. doi: 10.3390/ijms26062643.
PMID: 40141282DERIVEDKalinsky K, Bianchini G, Hamilton E, Graff SL, Park KH, Jeselsohn R, Demirci U, Martin M, Layman RM, Hurvitz SA, Sammons S, Kaufman PA, Munoz M, Lai JI, Knoderer H, Sandoval C, Chawla AR, Nguyen B, Zhou Y, Ravenberg E, Litchfield LM, Smyth L, Wander SA. Abemaciclib Plus Fulvestrant in Advanced Breast Cancer After Progression on CDK4/6 Inhibition: Results From the Phase III postMONARCH Trial. J Clin Oncol. 2025 Mar 20;43(9):1101-1112. doi: 10.1200/JCO-24-02086. Epub 2024 Dec 18.
PMID: 39693591DERIVED
Related Links
MeSH Terms
Conditions
Interventions
Condition Hierarchy (Ancestors)
Intervention Hierarchy (Ancestors)
Results Point of Contact
- Title
- Chief Medical Officer
- Organization
- Eli Lilly and Company
Study Officials
- STUDY DIRECTOR
Call 1-877-CTLILLY (1-877-285-4559) or 1-317-615-4559 Mon - Fri 9 AM - 5 PM Eastern time (UTC/GMT - 5 hours, EST)
Eli Lilly and Company
Publication Agreements
- PI is Sponsor Employee
- No
- Restriction Type
- LTE60
- Restrictive Agreement
- Yes
Study Design
- Study Type
- interventional
- Phase
- phase 3
- Allocation
- RANDOMIZED
- Masking
- DOUBLE
- Who Masked
- PARTICIPANT, INVESTIGATOR
- Purpose
- TREATMENT
- Intervention Model
- PARALLEL
- Sponsor Type
- INDUSTRY
- Responsible Party
- SPONSOR
- Expanded Access
- Yes
Study Record Dates
First Submitted
December 22, 2021
First Posted
December 27, 2021
Study Start
March 11, 2022
Primary Completion
February 8, 2024
Study Completion (Estimated)
December 1, 2027
Last Updated
January 16, 2026
Results First Posted
February 27, 2025
Record last verified: 2025-12
Data Sharing
- IPD Sharing
- Will share
- Shared Documents
- STUDY PROTOCOL, SAP, CSR
- Time Frame
- Data are available 6 months after the primary publication and approval of the indication studied in the US and European Union (EU), whichever is later. Data will be indefinitely available for requesting.
- Access Criteria
- A research proposal must be approved by an independent review panel and researchers must sign a data sharing agreement.
Anonymized individual patient level data will be provided in a secure access environment upon approval of a research proposal and a signed data sharing agreement.