Prescribers differ among specialties
We should note that prescriber attitudes differ among clinical areas. Some specialties have seen quite a bit of biosimilar activity — for example, rheumatology and gastroenterology. But other areas, like dermatology and ophthalmology, are less experienced with these products.17
In a recent survey, 86% of gastroenterologists and 62% of rheumatologists said they are “very comfortable” prescribing biosimilars to their patients.18
But the same survey found that only 35% of dermatologists fell in to the "very comfortable" category. Interestingly, 56% of ophthalmologists said they would be willing to prescribe a biosimilar — but only if it had achieved the FDA interchangeability designation (see below).19
It is well known that the U.S. has one of the most complex health care systems in the world.20 And the clinical, financial and legal issues surrounding biosimilar drugs are correspondingly complex.
Consequently, the system is going to need to adopt new, streamlined processes in order to start realizing the benefits of biosimilars. These steps will include everything from patient and physician education to nitty gritty details like stocking and storing supplies of often temperature-sensitive medications.21 It’s going to take some time.
Biosimilar and biologic interchangeability
The basic concept of interchangeability should be familiar. Think of how almost any generic drug can be substituted at the pharmacy for a brand-name drug, without having to check with the doctor first (subject to state law).22
For biosimilars things are different, at least in the U.S. Broadly speaking, both U.S. and EU regulators must certify that biosimilars are as safe and effective as their reference products. Notably, EU regulators consider all their approved biosimilars to be interchangeable with their reference products without additional studies.23
The fact that no additional designation of interchangeability is required in the EU could be one reason for their highly successful biosimilar adoption rates.
But in the U.S., FDA rules have established a different category for biosimilars that have also been designated as interchangeable. An interchangeable biosimilar must meet additional requirements in order to be substituted for the reference product in the retail pharmacy setting.24
Switching among biosimilars
To be designated interchangeable, a biosimilar must undergo a "switching study." This is essentially an additional phase 3 trial, with all of the cost and time that entails. The goal is to make sure that clinical outcomes are the same even if patients are repeatedly switched between the reference product and the biosimilar.25
Some biosimilar manufacturers argue that establishing this new designation category could create needless doubts about non-designated biosimilars. In other words, Congress and the FDA may have unintentionally created the impression that designated interchangeables are somehow “better biosimilars.”26
Whether this will actually impede biosimilar acceptance into mainstream health care remains to be seen.27
One large distributor notes that, as biosimilars are moving into the pharmacy benefit, biosimilar makers will come to see interchangeability as a competitive advantage. That would make satisfying the extra regulatory requirements worthwhile.28
We can see this playing out with the Humira biosimilars that are currently approved, or pending approval. Of these, only one has the interchangeable designation (Cyltezo® — adalimumab-adbm). However, at least 5 other biosimilar competitors are currently seeking interchangeable status.29
This leads to an interesting question. If some Humira competitors are interchangeable, and some are not, will we see a difference in their uptake? This is worth watching.
Ensuring efficacy, safety and affordability
Bringing Humira biosimilars to the marketplace is one of the biggest opportunities in years to lower costs and increase accessibility for consumers. Along with including both Amjevita list price options, Optum Rx will be adding up to two more Humira biosimilars this year.
More broadly, this is an important moment for the health care system. As more biosimilars come to market, Optum Rx will continue to collaborate across the health care industry. Our goal is to ensure that these products are thoroughly evaluated, so that we can make informed decisions about whether they will be added to our formulary.
Critically, competition is vital to foster innovation and drive down the cost of prescription drugs. We encourage our colleagues across the health care sector to join us in supporting efforts to increase competition across the market.
This approach, as with all our formulary decisions across drug classes, is driven by our commitment to ensuring the clinical efficacy, safety and affordability of the drugs. Ultimately, this will offer greater affordability and choice for members with no disruption to treatment, while generating greater value within the health care system.