nextMONARCH: Abemaciclib + Tamoxifen can be a new hope for heavily pretreated HR+, HER2- metastatic Breast Cancer patients

Abstract No : Abstract 273O

Indication : Breast cancer

Intervention : Abemaciclib

Company : Lilly & Co.

Technology : CDK4/6 Inhibitor


At the time of data cutoff (28-June-2019), 12 of the 234 patients enrolled were still ongoing on study treatment. Median follow-up was 27.2 months. Median OS was 24.2 months in the A+T arm, compared to 20.8 months in A-150, and 17.0 months in A-200 (A+T vs. A-150: HR 0.620 (95% CI [0.397, 0.969] p=0.034); A-150 vs. A-200: HR 0.956 (95% CI [0.635, 1.438] p=0.832)). The primary PFS endpoint and ORR were unchanged at the 24-month analysis. Common treatment-emergent adverse events (TEAEs) across all abemaciclib arms occurring in ≥25% of patients included diarrhea (61.1%), neutropenia (49.6%), anemia (40.6%), nausea (36.3%), leukopenia (30.8%), fatigue (29.9%) and abdominal pain (27.4%)


Addition of tamoxifen to abemaciclib provided a statistically significant median OS improvement compared to abemaciclib monotherapy in this heavily pretreated HR+, HER2- MBC patient population. PFS was consistent with the primary results of nextMONARCH with no significant difference. No new safety findings were observed