Recently, Eli Lilly and Company announced that the US FDA has approved the expanded indications of the CDK4/6 inhibitor Verzenio (abemaciclib), combined with endocrine therapy (tamoxifen or aromatase inhibitor), and adjuvant therapy for hormone receptor positive (HR+) , Human epidermal growth factor receptor 2 negative (HER2-), lymph node positive, early breast cancer patients with high risk of recurrence. These patients were determined to have a Ki-67 score of ≥20% by a test approved by the US FDA. Ki-67 is a marker of cell proliferation. The press release states that Verzenio is the first CDK4/6 inhibitor approved for use in this patient population.

Breast cancer has surpassed lung cancer as the most common cancer in the world, with approximately 2.3 million newly diagnosed patients in 2020. It is estimated that about 90% of breast cancer patients are in the early stage of cancer when they are diagnosed. Although most early-stage HR+, HER2- breast cancer patients have a positive prognosis, about 20% of patients will relapse and may develop metastatic disease. Patients with cancer cells and other high-risk characteristics found in the lymph nodes are more likely to relapse, and they need innovative therapies to prevent the recurrence of the disease.

This approval is based on an open-label, phase 3 clinical trial of patient subgroup analysis results. This patient subgroup includes more than 2,000 patients with a variety of high-risk recurrence characteristics, including Ki-67 score ≥20%, cancer cells found in more than four axillary lymph nodes, or cancer cells found in 1-3 axillary lymph nodes and The size of the tumor exceeds 5 cm and so on.

The analysis of this patient subgroup showed that Verzenio combined with endocrine therapy, compared with endocrine therapy alone, reduced the risk of recurrence in patients by approximately 36% (HR=0.643, 95% CI: 0.475, 0.872, p=0.0042). In the Verzenio combination therapy group, 104 recurrences of aggressive disease occurred, and the value in the endocrine therapy single-agent group was 158. The overall survival data is not yet mature.

Verzenio (abemaciclib) is a CDK4/6 inhibitor. In HR+ breast cancer cell lines, cyclin D1 and CDK4/6 promote cell cycle progression and cell proliferation. Verzenio can block the progression of the cell cycle, leading to cell senescence and apoptosis. It has been approved by the FDA as a first-line therapy for HR+, HER2- advanced breast cancer patients.