Misinformation about interchangeable biosimilars undermines US health policy, physician confidence, and patient health

The US biosimilar programme has been highly successful with 53 biosimilars approved by the US Food and Drug Administration (FDA) for 17 reference products. As in most advanced nations of Europe, all FDA-approved biosimilars may be substituted in place of the reference product by the physician. To be substitutable at the pharmacy level, however, US state law requires these to be FDA-approved as 'interchangeable biosimilars'--a designation earned through additional data showing no loss of safety or efficacy is expected even after multiple switches, relative to a patient who remained on the reference product. Thirteen biosimilars have earned this designation. FDA currently has the flexibility to determine how these data requirements are met; this can include switching studies, however, multiple interchangeable biosimilars have been approved without them. This data-driven approach has significantly bolstered physician and patient confidence in biosimilar safety and efficacy, particularly regarding pharmacy substitution. Yet there has recently been a push by policymakers at many levels of government to limit the types of data the FDA can consider, or otherwise lower the data requirements. The authors of this article critically examine a meta-analysis frequently cited by policymakers supportive of these efforts. They argue that the study's conclusions--and the policy proposals--are unsupported by the data, which do not address efficacy impacts and extrapolate multi-switch safety despite a disproportionate reliance on single-switch studies. Rushing to dismantle proven standards based on these and other misconceptions, the authors argue, poses a potential risk to patient treatment stability and confidence in biosimilars. Preserving the quality standards that have defined the introduction of interchangeable biosimilars in the US, and the FDA's flexibility to seek additional data when needed, will help ensure that patient care remains personalized and the integrity of the patient--physician relationship is maintained. Keywords: biosimilarity, interchangeability, regulation, uptake