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Biosimilars: To Switch or Not to Switch? That Is The Question!

If you’re interested in new and emerging treatments for rheumatoid arthritis (RA), you’ve probably at least heard the term “biosimilars.” But what exactly are biosimilars? And what should you do if your doctor recommends one?

Back to basics: Biologics

To understand what biosimilars are, we have to start with biologics. A biologic medication is a large molecule medication made from living cells. These molecules are extremely complex, often 200 to 1,000 times the size of widely used small molecule drugs. The metaphor I’ve heard to help us understand the complexity of these molecules is that if an aspirin (acetaminophen) is as complicated as a log cabin, a biologic is as complicated as the Empire State Building. Biologic medications often require special handling, like refrigeration, and generally need to be administered via injection or infusion.

Small molecule drugs, like aspirin, are synthesized from chemicals in a consistent process, so manufactures can be sure that each pill has the same effect every time. That means that when the patent surrounding the drug’s formula expires, a generic can be created that is identical. But when the patent on a biologic expires, it isn’t quite so easy to create a copy because the molecules are so complex and made from living cells. So, unlike generic medications, biosimilars by definition are not exactly identical to their originator biologic. They are similar, but they might have slight variations in their structure.

So are biosimilars good or bad for patients? That was the focus of the Great Debate at the American College of Rheumatology (ACR) Annual Meeting in San Diego, California in November 2017. Dr. Jonathan Kay, Professor of Medicine at the University of Massachusetts, presented the “pro” argument on the usefulness of biosimilars. Dr. Roy Fleischmann, Clinical Professor at the University of Texas Southwester Medical Center, offered the “con” argument that the research surrounding biosimilars has not provided enough evidence that switching can be confidently allowed.

Pro: Biosimilars Are Safe, Effective, and Cost-Effective

Dr. Kay began his argument by explaining that originator biologics themselves are subject to variability. Because biologics are produced from living cells, one batch of a biologic may be every so slightly different from another batch of the same medication. Biologics are also subject to unintended alterations in the manufacturing process as well as deliberate process changes that could result in additional variability.

Dr. Kay’s point was that even commercial lots of the same biologic medication are not identical to one another, which he demonstrated by showing a slide that revealed the slight differences in U.S. and EU sourced batches of Remicade (infliximab). Because approved biosimilars have been shown to be highly similar to their reference product, Dr. Kay argued that an approved biosimilars is really no different from the reference molecule than the reference molecule may be from other batches of itself.

In addition to arguing that biosimilars are comparable to biologics in terms of safety and efficacy, Dr. Kay emphasized the potential cost benefits for patients. As biosimilars are developed market competition is introduced, which should affect not just the price of the originator biologic but also the price of the whole product class. Overall, Dr. Kay concluded that biosimilars create greater global access to effective treatment options at a lower cost.

Con: The Data on Biosimilars is Not Convincing

On the issue of safety and efficacy, Dr. Fleischmann argued that there isn’t yet sufficient convincing data to say that biosimilars are non-inferior to their originator biologics. He presented data from a study (NOR-SWITCH) where a clinically meaningful number of patients lost efficacy and developed adverse effects when switched from a biologic to the biosimilars. He concluded that we still need more safety data, for a longer period of time covering many more patients, to fully understand the safety and efficacy of biosimilars.

Dr. Fleischmann also emphasized that the main rationale for biosimilars is not only that they should be safe and effective but, more importantly, that they should be cheaper than biologics, giving more patients access to needed treatments. However, he argued that this isn’t necessarily the case, at least in the United States, because of our system of pharmacy benefit managers (PBMs). Dr. Fleischmann contended that even in instances where biosimilars would result in reduced prices, insurers and PBMS, rather than patients, would generally see these savings. And, without giving the patients access to cheaper treatment options, he reasoned that there is no value in using a biosimilars.


So what should you do if your doctor recommends trying a biosimilars? While I obviously can’t give you medical advice, I can advise you to ask a lot of questions. Why is your doctor recommending a biosimilars? Are you out of biologic options? Does he/she have reason to think the biosimilar might work better? Will it save you a lot of money? How long has the biosimilars been on the market and what do we know about it?

Data about biosimilars is still emerging – and clearly even the leading experts don’t necessarily agree on the answers to these questions. So when it comes to making decisions for your own treatment plan, make sure you get as much information as possible before you decide.

This article represents the opinions, thoughts, and experiences of the author; none of this content has been paid for by any advertiser. The team does not recommend or endorse any products or treatments discussed herein. Learn more about how we maintain editorial integrity here.


  • philjania
    2 years ago

    I have a bad experience with biosimilars. I was successfully controlled with Enbrel brand etanercept when I was ‘offered’ Benepali brand etanercept as the biosimilar product. By offered I mean I was given no choice at the time. The reasoning was that the Benepali brand was significantly less expensive. I was not given any background info, only instructions on how to use the new pen. Within one week of starting the Benepali, my symptoms were worsening. By the end of week 4, I was back to square one with pain and inflammation everywhere. I insisted that I get a review to get put back onto Enbrel. To be fair, the local NHS trust listened and reverted immediately to Enbrel. They insisted that they had no record of any such instances. I’ve been back on Enbrel now for 4 months and if anything I’m getting progressively worse. My consultant has suggested that I have developed a resistance through antibodies to the etanercept and it has therefore stopped working. My opinion is that Benepali ‘opened the door’ to my immune system and made the whole thing fail. I now have to wait to be reassessed to move onto the next line of biologics. My advice would be that if you are already on the reference drug then stay on it. Biosimilars should only be administered to those patients that are new to biologics.

  • Carla Kienast
    2 years ago

    Mariah: Great article with excellent points. Only patient experience will tell us what the benefits (effective treatment, financially more affordable) or concerns are. I’m just happy that more treatment options are available.

  • Lawrence 'rick' Phillips moderator
    2 years ago

    I watched this debate and came away with my mind changed. Biosimilars need to offer cost advantages before I will switch. Yes a few dollars mean a lot, or it mean nothing, for me I would rather make sure I am saving enough to risk a four month period with no relief if the biosimilar fails.

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