Abemaciclib plus non-steroidal aromatase inhibitor or fulvestrant in women with HR+/HER2- advanced breast cancer: Final results of the randomized phase III MONARCH plus trial.

ABSTRACT:

Background

In the interim analysis of MONARCH plus, adding abemaciclib to endocrine therapy (ET) improved progression-free survival (PFS) and objective response rate (ORR) in predominantly Chinese postmenopausal women with HR+/HER2- advanced breast cancer (ABC). This study presents the final pre-planned PFS analysis.

Methods

In the phase III MONARCH plus study, postmenopausal women in China, India, Brazil, and South Africa with HR+/HER2- ABC without prior systemic therapy in an advanced setting (cohort A) or progression on prior ET (cohort B) were randomized (2:1) to abemaciclib (150 mg twice daily [BID]) or placebo plus: anastrozole (1.0 mg/day) or letrozole (2.5 mg/day) (cohort A) or fulvestrant (500 mg on days 1 and 15 of cycle 1 and then on day 1 of each subsequent cycle

SUBMITTER: Hu X 

PROVIDER: S-EPMC12180841 | biostudies-literature | 2025 Jun

REPOSITORIES: biostudies-literature