A Study of Nonsteroidal Aromatase Inhibitors Plus Abemaciclib (LY2835219) in Postmenopausal Women With Breast Cancer (MONARCH 3)

Brief Summary:
The main purpose of this study is to evaluate how effective nonsteroidal aromatase inhibitors (NSAI) plus abemaciclib are in postmenopausal women with breast cancer. Participants will be randomized to abemaciclib or placebo in a 2:1 ratio.


Study Type: Interventional  (Clinical Trial)
Actual Enrollment: 493 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double (Participant, Care Provider)
Primary Purpose: Treatment
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
Actual Study Start Date: November 6, 2014
Actual Primary Completion Date: January 31, 2017
Estimated Study Completion Date: July 12, 2021

Arms:
- Experimental: Abemaciclib + NSAI
- Placebo Comparator: Placebo + NSAI