OBJECTIVES

Biosimilar uptake has been slow in the U.S. despite the potential to save the health system billions of dollars. This research focuses on the recent launches of three biosimilars, expanding on earlier studies by examining characteristics of physicians and patients that are correlated with early, late, and non-adoption of biosimilar medications. Understanding these characteristics can help policymakers and payers understand where to target interventions to increase the uptake of biosimilars.

METHODS

Using a 20% Medicare Part B file between 2014 and 2017 we identified all patients who were prescribed at least one medication in the Neupogen and Remicade drug classes. We compared physicians who never prescribed a biosimilar to early and later biosimilar adopters. We also compared patient characteristics between patients who never received a biosimilar to those who only received a biologic and separately between patients who never received a biosimilar to those who switched from a biologic to a biosimilar.

RESULTS

Across both drug classes, physicians who prescribed biosimilars relative to those who did not practiced in smaller groups on average (mean group size 131 vs 154 physicians for Neupogen and 95 vs 152 physicians for Remicaide, P=0.004 and <0.001) and were less likely to practice in the Northeast (9 vs 18% for Neupogen and 8% vs 16% for Remicade, P<0.001 for both). Few differences existed across patient categories. Patients who only received biologics had a similar number of chronic condition relative to those who only received biosimilars (P>0.05 for both drug classes).

CONCLUSIONS

Physician characteristics appear to be more important than patient characteristics in determining whether a patient receives a biosimilar or an originator biologic. Physicians in larger practices, who are likely to be better able to negotiate higher discounts off the list price for originator biologic medications, were less likely to prescribe biosimilars.