Abemaciclib (LY2835219) Plus Fulvestrant Compared to Placebo Plus Fulvestrant in Previously Treated Breast Cancer (postMONARCH)
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The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details. |
ClinicalTrials.gov Identifier: NCT05169567 |
Recruitment Status :
Recruiting
First Posted : December 27, 2021
Last Update Posted : May 24, 2023
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Condition or disease | Intervention/treatment | Phase |
---|---|---|
Breast Neoplasm Neoplasm Metastasis | Drug: Abemaciclib Drug: Fulvestrant Drug: Placebo | Phase 3 |
Expanded Access : An investigational treatment associated with this study is available outside the clinical trial. More info ...
Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 350 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Masking: | Double (Participant, Investigator) |
Primary Purpose: | Treatment |
Official Title: | 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 |
Actual Study Start Date : | March 11, 2022 |
Estimated Primary Completion Date : | August 4, 2023 |
Estimated Study Completion Date : | February 16, 2026 |

Arm | Intervention/treatment |
---|---|
Experimental: Arm A: Abemaciclib plus Fulvestrant
Abemaciclib administered orally in combination with fulvestrant administered intramuscularly (IM).
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Drug: Abemaciclib
Administered orally. Drug: Fulvestrant Administered IM. |
Active Comparator: Arm B: Placebo plus Fulvestrant
Placebo administered orally in combination with fulvestrant administered IM.
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Drug: Fulvestrant
Administered IM. Drug: Placebo Administered orally. |
- Progression-Free Survival (PFS) [ Time Frame: Randomization to the date of first documented progression of disease or death from any cause (estimated as up to 3 years) ]Investigator assessment
- Overall Survival (OS) [ Time Frame: Randomization until death from any cause (estimated as up to 5 years) ]OS
- PFS [ Time Frame: Randomization to the date of first documented progression of disease or death from any cause(estimated as up to 3 years) ]Blinded independent review
- Objective Response Rate (ORR): Percentage of Participants Who Achieve a Confirmed Best Overall Response of Complete Response (CR) or Partial Response (PR) [ Time Frame: Randomization until measured progressive disease (estimated as up to 1 year) ]ORR
- Clinical Benefit Rate (CBR): Percentage of Participants Who Achieve a Best Overall Response of CR, PR or Stable Disease for Greater than or Equal to (≥) 24 Weeks [ Time Frame: Randomization until measured progressive disease (estimated as up to 1 year) ]CBR
- Disease Control Rate (DCR): Percentage of Participants with a Best Overall Response of CR, PR, and stable disease (SD) [ Time Frame: Randomization until measured progressive disease (estimated as up to 1 year) ]DCR: Percentage of Participants with a Best Overall Response of CR, PR, and SD
- Duration of Response (DoR) [ Time Frame: Date of CR or PR to date of disease progression or death due to any cause (estimated up to 3 years) ]DoR
- Time to First Worsening of the Brief Pain Inventory Short Form Modified (mBPI-sf) "Worst Pain Score" [ Time Frame: Randomization through Follow-up (estimated as up to 3 years) ]The mBPI-sf "Worst pain" is a single self-reported item that measures the severity of pain based on the worst pain experienced over the past 24 hours. The severity scores range from 0 (no pain) to 10 (pain as severe as you can imagine).
- Time to Deterioration in Physical Function [ Time Frame: Randomization through Follow-up (estimated as up to 3 years) ]Physical Function scale includes five items (trouble with strenuous activities; trouble with long walk; trouble with short walk; need to stay in bed or chair; need help with eating, dressing, washing, toilet) in the European Organization for Research and Treatment of Cancer Item Library 19 (EORTC-19). Response options range from 0 ("not all") to 4 ("very much.") Higher composite scale scores indicate higher function.
- Pharmacokinetics (PK): Mean Steady State Concentrations of Abemaciclib [ Time Frame: Day 1 of Cycle 3 (Cycle = 28 days) ]PK: Mean Steady State Concentrations of Abemaciclib

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.
Ages Eligible for Study: | 18 Years and older (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
- Have a diagnosis of HR+, HER2- locally advanced or metastatic breast cancer
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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
Exclusion Criteria:
- 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

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT05169567
Contact: There may be multiple sites in this clinical trial. 1-877-CTLILLY (1-877-285-4559) or | 1-317-615-4559 | ClinicalTrials.gov@lilly.com |

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 |
Responsible Party: | Eli Lilly and Company |
ClinicalTrials.gov Identifier: | NCT05169567 |
Other Study ID Numbers: |
18238 I3Y-MC-JPEF ( Other Identifier: Eli Lilly and Company ) 2021-002301-10 ( EudraCT Number ) |
First Posted: | December 27, 2021 Key Record Dates |
Last Update Posted: | May 24, 2023 |
Last Verified: | May 2023 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | Yes |
Plan Description: | 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. |
Supporting Materials: |
Study Protocol Statistical Analysis Plan (SAP) Clinical Study Report (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. |
URL: | https://vivli.org/ |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | No |
Neoplasms Neoplasm Metastasis Breast Neoplasms Neoplastic Processes Pathologic Processes Neoplasms by Site Breast Diseases Skin Diseases |
Fulvestrant Antineoplastic Agents, Hormonal Antineoplastic Agents Estrogen Receptor Antagonists Estrogen Antagonists Hormone Antagonists Hormones, Hormone Substitutes, and Hormone Antagonists Physiological Effects of Drugs |