Abemaciclib (LY2835219) Plus Fulvestrant Compared to Placebo Plus Fulvestrant in Previously Treated Breast Cancer (postMONARCH)

Lilly

Status and phase: Active, not recruiting; Phase 3

Conditions: Breast Neoplasm; Neoplasm Metastasis

Treatments: Drug: Fulvestrant; Drug: Placebo; Drug: Abemaciclib

Study type: Interventional

Funder types: Industry

Identifiers

NCT05169567

18238

I3Y-MC-JPEF (Other Identifier)

2021-002301-10 (EudraCT Number)

2023-506771-10-00 (Other Identifier)

Details and patient eligibility

About

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.

Enrollment: 368 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• 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

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

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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368 participants in 2 patient groups

Arm A: Abemaciclib plus Fulvestrant

Experimental group

Description:

Abemaciclib administered orally in combination with fulvestrant administered intramuscularly (IM).

Treatment:

Drug: Abemaciclib

Drug: Fulvestrant

Arm B: Placebo plus Fulvestrant

Active Comparator group

Description:

Placebo administered orally in combination with fulvestrant administered IM.

Treatment:

Drug: Placebo

Drug: Fulvestrant