Both are CDK4/6 inhibitors. Here is how Kisqali and Verzenio compare on class, mechanism, dosing, approval and supply.
KISQALI is a kinase inhibitor indicated: in combination with an aromatase inhibitor for the adjuvant treatment of adults with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative stage II and III early breast cancer at high risk of recurrence. ( 1 ) for the treatment of adults with HR-positive, HER2-negative advanced or metastatic breast cancer in combination with: an aromatase inhibitor as initial endocrine-based therapy; or fulvestrant as initial endocrine-based therapy or following disease progression on endocrine therapy. ( 1 ) 1.1 Early Breast Cancer KISQALI is indicated in combination with an aromatase inhibitor for the adjuvant treatment of adults with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative stage II and III early breast cancer at high risk of recurrence. 1.2 Advanced or Metastatic Breast Cancer …
VERZENIO ® is a kinase inhibitor indicated: in combination with endocrine therapy (tamoxifen or an aromatase inhibitor) for the adjuvant treatment of adult patients with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative, node-positive, early breast cancer at high risk of recurrence. ( 1.1 , 14.1 ) in combination with an aromatase inhibitor as initial endocrine-based therapy for the treatment of adult patients with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced or metastatic breast cancer. ( 1.2 ) in combination with fulvestrant for the treatment of adult patients with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced or metastatic breast cancer with disease progression following endocrine therapy. ( 1.2 ) as monotherapy for the treatment of adult pati…
12.1 Mechanism of Action Ribociclib is an inhibitor of cyclin-dependent kinase (CDK) 4 and 6. These kinases are activated upon binding to D-cyclins and are downstream of signaling pathways which lead to cell cycle progression and cellular proliferation. The cyclin D-CDK4/6 complex regulates cell cycle progression through phosphorylation of the retinoblastoma protein (pRb). In vitro , ribociclib decreased pRb phosphorylation, resulting in arrest in the G1 phase of the cell cycle and reduced proliferation in breast cancer-derived models. In vivo , treatment with single agent ribociclib in a rat xenograft model with human tumor cells led to decreased tumor volumes, which correlated with inhibi…
12.1 Mechanism of Action Abemaciclib is an inhibitor of cyclin-dependent kinases 4 and 6 (CDK4 and CDK6). These kinases are activated upon binding to D-cyclins. In estrogen receptor-positive (ER+) breast cancer cell lines, cyclin D1 and CDK4/6 promote phosphorylation of the retinoblastoma protein (Rb), cell cycle progression, and cell proliferation. In vitro, continuous exposure to abemaciclib inhibited Rb phosphorylation and blocked progression from G1 into S phase of the cell cycle, resulting in senescence and apoptosis. In breast cancer xenograft models, abemaciclib dosed daily without interruption as a single agent or in combination with antiestrogens resulted in reduction of tumor size.
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Plain-English summaries and drug-class explainers are written and reviewed by the Priya Life Science editorial team, led by Sreepriya Prasannan (MSc Digital Transformation of Life Sciences (Innopharma Education / Griffith College); MSc & BSc Botany). Data is retrieved automatically from the sources above and cross-checked with AI-assisted verification (Anthropic's Claude) — brand and generic names are matched against the exact FDA product record so that a combination product or a different formulation cannot be mistaken for the drug on this page. An editor reviews the result before publication. We describe this in full in our editorial standards and corrections policy. The FDA data on this page was last retrieved on 6 Aug 2026.