Since IQVIA published Controlling Cancer Care: The Emergence of Formulary Exclusions in Oncology in 2021, national payers have expanded their use of formulary exclusions. Oncology itself is a largely expanding therapeutic class with new indications, novel brands, generics, and biosimilars continuing to launch in the U.S. As established in past research, the pipeline of new oncology therapies provides important treatment options to patients and their providers. Yet, the increase in competition also creates opportunities for payers to manage treatment and contract for access. As these dynamics occur, two questions remain open: How do clinical guidelines influence formulary exclusions, if at all? Can brand access and performance recover once formulary exclusions are removed?

This paper revisits the largest national formularies and expands upon previous research by incorporating National Comprehensive Cancer Network (NCCN) guidelines and IQVIA’s longitudinal claims data.