Real-World Clinical and Economic Outcomes Associated with Palbociclib for HR-Positive/HER2 Negative Metastatic Breast Cancer: A Commentary

Despite the achieved advancement in pharmacological cancer treatments, the majority of postmenopausal women with hormone receptor-positive metastatic breast cancer (mBC) will experience disease progression. Research into alternative therapies with improved efficacy and reduced side effects has led to the development of a new class of oral anticancer medications, the cyclin-dependent kinase (CDK) 4/6 inhibitors, which include palbociclib, ribociclib, and abemaciclib. Nonetheless, there is growing evidence that the effectiveness of oral anticancer medications is sub-optimal, being influenced by low adherence, sociodemographic factors, and adverse effect profiles. In addition, there is a disconnect between the high price tags of CDK 4/6 inhibitors and their observed effectiveness, raising questions about their value. Currently, the existing knowledge base on the effectiveness and cost-effectiveness of newer oral anticancer medications in understudied populations with possible health disparities is scant. This commentary discusses what is known about palbociclib’s clinical effectiveness, safety, and adherence and suggests the need for further studies of real-world effectiveness and cost-effectiveness to help establish the value of newer oncologic drugs, such as palbociclib.