Abemaciclib is an antitumor agent and dual inhibitor of cyclin-dependent kinases 4 (CDK4) and 6 (CDK6) that are involved in the cell cycle and promotion of cancer cell growth in case of unregulated activity. On September 28, 2017, FDA granted approval of abemaciclib treatment under the market name Verzenio for the treatment of HR-positive and HER2-negative advanced or metastatic breast cancer that has progressed after unsuccessful endocrine therapy. It is either given alone in patients who has undergone endocrine therapy and chemotherapy after the metastasis of cancer, or in combination with [DB00947]. Following oral treatment in patients with HR-positive, HER2-negative breast cancer, abemaciclib demonstrated increased progression-free survival rates and objective response rates. Abemaciclib has been used in trials studying the treatment of melanoma, lymphoma, neoplasm, solid tumor, and glioblastoma.