Introduction: Advances in pharmacotherapies that target cell cycle in breast cancer have transformed the therapeutic armamentarium of breast oncology leading to the approval of CDK4/6 inhibitors plus endocrine therapy as the upfront treatment in the HR+/HER2- metastatic setting. The current challenge is to evaluate the efficacy of these drugs in the early setting. The current challenge is to evaluate the efficacy of these drugs in the early setting. Research is also making progress for other breast cancer subtypes (triple negative and HER 2+ breast cancer).
Areas covered: The aim of this review is to summarize the recent therapeutic updates regarding the efficacy of CDK4/6 inhibitors in the metastatic and early setting for the treatment of HR+/HER2- breast cancer. The review also presents data regarding the clinical role of CDK4/6 inhibitors in HER2+, triple negative breast cancer, and on therapeutic sequences in resistant tumors. A comprehensive search for the literature was conducted using MEDLINE, ASCO, ESMO, and SABCS databases.
Expert opinion: The therapeutic paradigm of breast cancer involving CDK4/6 inhibitors presents some still open discussion points. Further evidence regarding the best treatment strategy in HR+ HER2- metastatic breast cancer and the efficacy of CDK 4/6is in the early stage will be necessary in the next future. Predictive biomarkers of response or resistance need to be validated.
Keywords: Abemaciclib; CDK4/6 Inhibitors; HR+ breast cancer; Palbociclib; Ribociclib; cell cycle; targeted treatment.