On October 12, 2021, the FDA approved the combination of Verzenio (abemaciclib; from Eli Lilly) plus endocrine therapy (with tamoxifen or an aromatase inhibitor) for the adjuvant (additional) treatment of adults with hormone receptor (HR)-positive, HER2-negative, node-positive, early breast cancer that is at high risk of recurrence and a Ki-67 score ≥20%, as determined by an FDA approved test.
Verzenio is the first CDK4/6 inhibitor to receive FDA approval for the adjuvant treatment of early breast cancer.
On the same day, the FDA also approved the Ki-67 IHC MIB-1 pharmDx assay as a companion diagnostic test for selecting appropriate patients for this combination therapy.
This approval was based on a randomized, open-label, 2-cohort multicenter clinical trial. The study included women and men with HR-positive, HER2-negative, node-positive, resected, early breast cancer and clinical and pathological features consistent with a high risk of disease recurrence (coming back). Patients received Verzenio plus their physician’s choice of endocrine therapy or endocrine therapy alone for 2 years.
In the 2003 patients with high risk for disease recurrence and Ki-67 score ≥20%, the use of Verzenio plus endocrine therapy resulted in significant improvement in survival without invasive disease versus endocrine therapy alone. At 36 months, the rate of survival without invasive disease was 86.1% with Verzenio plus endocrine therapy compared with 79% with endocrine therapy alone.
The most common side effects with Verzenio plus endocrine therapy were diarrhea, infections, neutropenia, fatigue, leukopenia, nausea, anemia, and headache.
