FDA Expands Approval of Abemaciclib to Initial Treatment of Advanced Breast Cancer
On February 26, 2018, the U.S. Food and Drug Administration (FDA) approved abemaciclib (Verzenio) in combination with an aromatase inhibitor as an initial endocrine-based therapy for the treatment of postmenopausal women with advanced or metastatic breast cancer, as announced by Eli Lilly and Company. Abemaciclib is approved in combination with fulvestrant for the treatment of women with hormone receptor–positive, HER2-negative advanced or metastatic breast cancer with disease progression following endocrine therapy and as monotherapy for adult patients with hormone receptor–positive, HER2-negative advanced or metastatic breast cancer with disease progression following endocrine therapy and prior chemotherapy in the metastatic setting.
This expanded indication of abemaciclib as initial therapy in combination with an aromatase inhibitor is based on the efficacy and safety demonstrated in the randomized, double-blind, placebo-controlled MONARCH 3 trial. The study enrolled 493 postmenopausal women with hormone receptor–positive, HER2-negative breast cancer who had no prior systemic treatment for advanced disease.
Abemaciclib, dosed orally at 150 mg twice daily and administered alongside an aromatase inhibitor, demonstrated a median progression-free survival of 28.2 months, compared with 14.8 months with placebo. The objective response rate with abemaciclib was 55.4 % versus 40.2% with placebo. The most common adverse events reported in at least 20% of patients receiving abemaciclib in the MONARCH 3 trial and more than 2% higher than in the placebo arm were diarrhea, neutropenia, fatigue, infections, nausea, abdominal pain, anemia, vomiting, alopecia, decreased appetite, and leukopenia.