How Does Interchangeability Impact Biosimilar Adoption?

Biosimilar adoption could reduce health care spending and improve medication affordability. One barrier to adoption is that pharmacists are not permitted to substitute biosimilars for original biologics unless the biosimilar is deemed “interchangeable” by the Food and Drug Administration. This study will evaluate how interchangeability affects biosimilar adoption, whether the effects are different for new versus existing patients, and the role played by state substitution policies in mediating these effects. The study may offer valuable insights to policymakers assessing substitution laws.