Patients Rising Asks: Why Are Rheumatologists Hesitant to Switch Patients to Biosimilars?

Results from an online survey ( of board-certified U.S. rheumatologists found reluctance to switch patients from a reference biologic therapy to a biosimilar. This was especially true if the patient was responding well to the existing treatment. The lack of confidence in biosimilars is regardless of the disease being treated and has been seen in several other studies.


biologics and biosimilars

Biosimilar products are highly similar to their reference product, without any clinically meaningful difference from the ‘reference’ drug. Detailed information on the definition of a biosimilar and their safety, efficacy, and substitution can be found in an e-book published by Patients Rising University.

While biosimilar products have seen widespread uptake in Europe, providers show a lack of confidence in biosimilars in the U.S., either due to:

  • physician or patient skepticism
  • lack of health insurance coverage of biosimilars
  • existing contracts between hospitals and reference product manufacturers


For the current study, self-identified rheumatologists who see patients for 75% of their working week completed an online survey. The physicians were required to have prescribed a TNF-α inhibitor (infliximab, adalimumab, or etanercept) for treating an autoimmune disease. The 19-question survey focused on the following:

  • Physician familiarity with a biosimilar
  • Knowledge of currently available biosimilars
  • Reasons for choosing a biosimilar over a reference product
  • Knowledge of, and attitude towards, these terms: interchangeability, switching, extrapolation, non-medical switching, and totality of evidence (definitions of these terms can be found in the e-book)
  • Their likelihood of switching a patient to a biosimilar

The 320 rheumatologists whose responses were included in the final analysis had at least ten years of rheumatology practice experience.

  • A majority of respondents were knowledgable about the FDA definition of a biosimilar and felt that an interchangeability designation was important on a biosimilar’s label
  • Only about half the respondents were familiar with non-medical switching
    • About half of those familiar with non-medical switching* had patients for whom the switch had been recommended. *Non-medical switching literally means switching for reasons other than medical ones: insurance or formulary change, step therapy, etc.
  • There was wide variability in physician knowledge on whether a biosimilar for a particular TNF-α inhibitor was FDA approved or was still being developed
    • This could potentially influence prescription of that biosimilar
  • Physicians used varying criteria when prescribing a biosimilar for their patient
    • A majority ranked effectiveness as most important
    • Just over half ranked physicochemical/functional characteristics of the biosimilar as least important
    • Biosimilar safety and switching data (switched from a reference to a biosimilar) was important for less than half of respondents


Importantly, while 73% of respondents said they were likely to initiate treatment with a biosimilar for patients with rheumatoid arthritis (RA) who had never received a biologic before, only 35% were likely to switch an RA patient to a biosimilar if he or she was responding well to a reference biologic.

This study identifies several patient access barriers to biosimilar rheumatology products.

Surabhi Dangi-Garimella, Ph.D.

Surabhi Dangi-Garimella, Ph.D. is a biologist with academic research experience, who brought her skills and knowledge to the health care communications world. She provides writing and strategic support to non-profit groups via her consultancy, SDG AdvoHealth, LLC.

From the Editor:

This article makes reference to an e-book about Biologics and Biosimilars published by Patients Rising. That e-book happens to be a part of an educational module that we present through our Patients Rising University. The role of the “University” is to give patients and caregivers the most reliable knowledge possible. They can then make more informed decisions, and more productive conversations with their doctors.

The Amercian Journal of Managed Care has a great article on how to instill confidence in biosimilars.

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