Experience with prescribing CDK4/6 inhibitors for metastatic Her2-positive breast cancer in the St. Petersburg City Clinical Oncology Dispensary

Studies of drugs from the group of cyclin-dependent kinase 4/6 (CDK4/6) inhibitors as first-line therapy are currently not limited to the group of patients with metastatic luminal Her2-negative (ER+/HER2-) breast cancer. A number of preclinical and clinical studies have demonstrated the potential of CDK4/6 inhibitors in the treatment of HER2-positive breast cancer with positive expression of hormone receptors («triple-positive» subtype). However, in these studies, CDK4/6 inhibitors were used together with monoclonal antibodies (Trastuzumab, Pertuzumab). This article presents a case of using a combination of an aromatase inhibitor and a CDK4/6 inhibitor without chemotherapy and monoclonal antibody (MAB) drugs as a first-line treatment for metastatic Her2-positive breast cancer in the St. Petersburg City Clinical Oncology Dispensary.