The question of whether a biosimilar is as comparably effective as its originator has largely been put to rest by clinical trials, real-world experience and a recent FDA guidance.

However, this has not made biosimilars more accessible or affordable.

“As with all things in the prescription drug space, there are a lot of complexities to this,” Alex Keeton, executive director of the Biosimilars Council and senior vice president of policy at the Association for Accessible Medicines (AAM), said in an interview.

In October 2025, the FDA issued a draft guidance that aimed to accelerate biosimilar development by nixing the requirement for comparative efficacy studies, which can take 1 to 3 years and cost $24 million to complete, the agency said in a press release.

That draft guidance was followed by another in March, in which the agency recommended streamlining “unnecessary clinical pharmacokinetic (PK) testing when scientifically justified.” That change could save biosimilar developers up to 50% of their PK study costs, or approximately $20 million, and help lower drug costs, the FDA said.

Preceding all of this was the 2024 FDA draft guidance removing requirements for switching studies to determine biosimilars’ interchangeability with reference products.

According to John R.P. Tesser, MD, FACP, MACR, of Arizona Arthritis & Rheumatology Associates and the University of Arizona College of Medicine, in Phoenix, these changes could address major hurdles that have historically stymied biosimilar access and uptake in the rheumatology space.

“For a biosimilar to get interchangeability approved, the FDA previously required a switch study, where patients would be switched from a bio-originator to a biosimilar, and back again, to determine safety and efficacy,” Tesser told Healio. “According to the FDA draft guidance, that type of study, or any other alternating study, will not be necessary for the approval of interchangeability for a biosimilar anymore.”

The hope, ultimately, is to save time and money.

“Once a biosimilar molecule has been developed, these switch studies could take an extra 6 to 12 months and another $200 million to complete,” Tesser said.

However, whether that savings translates to reduced costs for patients is another story.

According to Keeton, there is often a temptation to draw comparisons with generic medications, which have been on payer formularies for decades.

“Adding biosimilars to formularies and removing access barriers is critical for promoting health and affordability,” Keeton said. “However, biologics are a bit more complicated than generics in terms of manufacturing and uptake, and this can lead to confusion when it comes to coverage and reimbursement.”

The complications compound in patients with chronic diseases who are often on therapy for all or most of their lives. Sometimes the payer will alter the formulary to include a biosimilar without alerting the patient or provider. In other cases, the physician and patient will want to switch to a biosimilar to save money, but the payer will require another prior authorization. Often, multiple preapprovals are required, on a quarterly basis or more frequently, according to Keeton.

“There can be a push and pull,” he said.

Untangling these specific scenarios can take significant time for most rheumatology practices, but there is hope that the FDA’s proposed changes, and subsequent legislation, will mitigate some of these concerns.

For Tesser, the end of comparative efficacy studies for biosimilars comes as a welcome development.

“Ten or 12 years ago, I would have said we absolutely need those human switching studies,” Tesser said. “I am not sure we need them now, having seen so many of these molecules perform as well as the originator.”

However, Aaron Broadwell, MD, assistant professor at the Louisiana State University Health Sciences Center, sees it differently.

“I have concerns about moving away from comparative efficacy studies as a routine part of biosimilar development,” he said. “Biologics are large, complex molecules and are inherently more difficult to reproduce than traditional small-molecule drugs.

“I understand the argument that increasingly sophisticated analytical testing, pharmacokinetic studies and other methods may be able to establish biosimilarity without a comparative efficacy trial in some circumstances,” he added. “However, I believe biosimilars should continue to be held to a very high evidentiary standard before they are marketed in the United States, and I would want to be confident that eliminating a comparative efficacy study does not lower that standard.”

According to Tesser, another potential concern pertains to the state of the factories where these medications are produced.

“There may be concerns with factory readiness and the purity of the molecules being produced,” he said. “This came into play recently when Fresenius Kabi recalled a batch of Tyenne (tocilizumab-aazg) due to the presence of glass particles.”

The resulting “fear and anxiety” underscores patient concerns about biosimilars, Tesser added.

Meanwhile, the AAM and the Biosimilars Council, which devote a significant amount of time to advocacy within Capitol Hill and statehouses to address these topics, point to communication with legislators is often as important as communication with patients, according to Keeton.

“Legislators are concerned that they are doing the right thing,” he said. “We have to assure them of the seriousness of the conditions that biologics treat. We have to assure them that the science is sound, and that production of these molecules is not some fly-by-night operation.”

However, even when taking into account all of the above obstacles, Tesser said he does not predict any move away from biosimilars in the future. Rather, he predicted that biosimilars may soon become just as entrenched in medical care as generic medications are today.

“We are on a conveyor belt,” Tesser said. “Our entire society is dealing with these drugs and moving toward what happened with small molecules after the Hatch-Waxman Act.”

The Hatch-Waxman Act, known officially as the Drug Price Competition and Patent Term Restoration Act, was enacted in 1984 and established regulations for distribution of generic medications in the United States.

“We will get to the point where we order tocilizumab or adalimumab with a biologic name, analogous to a generic name for a small molecule, and the patient will get whatever version is on the formulary,” he said. “The pharmacy will then be able to make the change from biologic to biosimilar, or biosimilar to biosimilar, without notifying us. But we are not there yet.”

Federal legislation may help improve biosimilar access, according to Keeton. He highlighted the recent U.S. Senate committee markup of the Expedited Access to Biosimilars Act, which was first introduced in the Senate in 2025 by Sen. Rand Paul, R, Ky. The bill would formally eliminate the requirement for clinical efficacy studies for biosimilars, except in cases where the FDA determines such a study is necessary. It has been referred to the Senate Committee on Health, Education, Labor, and Pensions, and was placed on the legislative calendar in July.

The House also has shown activity on the Biosimilar Red Tape Elimination Act, which would automatically deem all biosimilars approved by the FDA as interchangeable with their reference products. That bill, introduced in the U.S. Senate by Sen. Mike Lee (R, Utah) in 2025, with Sens. Jon Ossoff (D, Georgia), Ben Lujan (D, N.M.), and Margaret Hassan (D, N.H.), among others, as cosponsors, was also placed on the legislative calendar in July.

“The aim is to codify the FDA draft guidance from last year,” he said. “Both pieces of legislation have broad bipartisan support and will be important steps to take to improving access to biosimilars.”

These bills are of particular importance, according to Keeton, as any previous FDA draft guidance can be undone by regulators in the future.

“This is why enacting legislation is so important,” he said. “It puts a period at the end of the sentence.”

As those bills navigate Capitol Hill, rheumatologists and their patients will need as much information as possible about the biosimilar landscape.

Cardinal Health recently published its 2026 Biosimilars Report, which surveyed practices about biosimilar use and uptake.

Topline findings show that more than 90 agents have been approved since 2015. More are expected to be approved and placed on formularies for myriad conditions in the wake of the FDA draft guidance.

“It’s essential for payers to put lower cost biosimilars on their formularies,” Keeton said. “It is important for patients to have access to those medications as soon as they are available. The question is whether the changes are benefitting patients.”

Although the Cardinal Health report suggests that biosimilars have led to “more than $56 billion in healthcare savings,” further data showed that 26% of respondents — a mix of physicians, advanced practice providers, pharmacists and administrators from oncology/hematology, rheumatology and ophthalmology practices — were very concerned that the cost of biosimilars will eventually outweigh reimbursement rates, and would consider discontinuation for that reason. Meanwhile, 56% were somewhat concerned about the same issue.

“I am always struck to see the reported savings in the billions for biosimilars,” Katie Taylor, CRH-C, CMPM, CRMS, practice manager at Carondelet Rheumatology, in Leawood, Kansas, told Healio. “In my experience, the buy and bill products are not acquired at significant savings compared to the originators. The reimbursement for many of the IV biosimilars is less than the acquisition cost of the medication, so they come at a cost to the practice, and commonly we are not seeing a significant drop in the patients’ out of pocket responsibility.”

Out-of-pocket costs are a significant concern for many rheumatology patients who are required to take medications for years on end, and possibly for their entire lives. Further data from the Cardinal Health report show that 94% of participating practices view a stable reimbursement rate as “somewhat important” to “very important.”

This stability is often disrupted when patients are forced to change treatments by payers who add a biosimilar to the formulary, according to Broadwell.

“Copay assistance from manufacturers for biosimilar products is either less generous than it is for the biologic product or non-existent,” he told Healio. “Every change can create another opportunity for prior authorization problems, prescription delays, missed doses, or confusion for the patient.”

Patients commonly report that they do not do as well after a switch, Broadwell added.

“This can be particularly concerning with drugs such as adalimumab when patients may be switched among multiple products over time,” he said. “From the patient perspective, I think the two biggest issues are continuity of care and access to adequate financial assistance.”

The Cardinal Health report drilled down on some of these issues. Other results showed that 84% of participating practices reported feeling “very supported” or “somewhat supported” with billing and reimbursement processes.

Taylor, who deals directly with formularies as part of her duties as a practice manager, said her experiences do not necessarily align with those who responded to the Cardinal Health survey.

“We are seeing formulary changes on the subcutaneous/self-administered side quarterly,” she said. “For the adalimumab products, we are prescribing all the way down to the specific NDC number.”

Taylor outlined the specific challenges administrators face.

“The problem is not only getting approval for a particular version of this medication, but also making sure that the specialty pharmacy can fulfill that order for the patient.”

The pharmacy benefit manager (PBM) provides practices with an established formulary, according to Taylor.

“However, we are seeing some cases where the only products actually available for dispensing and shipping are sometimes versions that are owned or manufactured by a company affiliated with the PBM,” she said. “In our experience, each of these various versions require a new prior authorization.”

Consequently, a “huge part” of Taylor’s workload is merely getting patients access to therapy, she said. The stresses are myriad, complex and can change from day to day.

“We have biosimilar manufacturers that get on the preferred formulary list, but then are unable to keep up with the product demand,” Taylor said. “Last month, I had a patient that was mandated to switch to a biosimilar, which is on allocation. My distributor was able to get me a one-time approval for this patient’s dose, with no long-term guarantee.”

Taylor noted that the patient needs to take the drug every 28 days and has been stable on it for 14 years.

“It is too much of a burden for me or my staff to beg for allocation on this, and it is not fair to the patient to potentially switch their medication every other treatment,” she said. “We petitioned the payer and we were granted a 90-day approval on the originator while the supply chain stabilizes.”

The difficulties reported by Taylor track with additional data from the Cardinal Health report, which showed that 74% of participating practices stated that they check average sales price quarterly or more often.

“Rheumatologists sometimes have to send new prescriptions on a quarterly basis because of changing formularies and preferred biosimilars,” Broadwell said. “It can be very difficult to determine up front which biosimilar a particular patient’s plan prefers. Rather than simply denying a prescription for the originator or a nonpreferred biosimilar, it would be much more helpful for the insurer or PBM to immediately tell the prescriber which biosimilar is preferred so that the prescription can be rewritten. That process should be as close to instantaneous as possible to minimize unnecessary delays in treatment.”

These system-level complications make it difficult to communicate with patients.

“We all want to educate and inform our patients ahead of time about these topics of biologics, biosimilars and interchangeability,” Tesser said. “We try to reassure them that it will be ok.”

Still, patients persistently have one key question in mind when they are switched to a biosimilar.

“Patients do seem to understand biosimilars and why they are around,” Taylor said. “But they ask whether it will still work. That is the most common question from patients. They mostly want confirmation that the change to a biosimilar will not have a negative impact on their health.”

Staying abreast of the market to track which agents are emerging, and likely to end up on formularies, is also critical for counseling patients, according to Taylor.

“Our providers and support staff watch the landscape and start counseling patients as soon as we know there is a biosimilar pursuing FDA approval, so there is no big shock or surprise to patients when they are ultimately switched,” she said. “We educate about the distinctions between a biosimilar, originator, and a generic product.”

Taylor’s group also informs patients that any individual’s response to any given agent may vary based on a wide variety of factors.

“But we assure them that we support the use of these products and trust the science behind them,” she said. “Patients want to hear that we support the change, and that our expectation is that these agents will work.”

To that end, Taylor encouraged rheumatologists to accept the reality of non-medical switching.

“We have not been very successful appealing the switch to a biosimilar,” she said. “For the few that insist that we challenge the biosimilar mandate, they get tired of waiting through the appeal processes and just want on therapy.”

Patients seldom pursue resources to help offset costs on their own behalf, according to Taylor.

“They often rely on the provider office for this work to be done,” she said. “Even the few patients who have joined the fight, paired with our efforts, are not always successful in overcoming the mandate.”

Meanwhile, the most optimistic players in the biosimilar space believe that FDA guidance, paried with ensuing legislation, may eliminate these daily operational challenges. The next few years will be pivotal to understanding the exact space biosimilars will occupy in the rheumatology treatment landscape, according to Keeton.

“We see some really exciting opportunities and developments in the biosimilar space,” he said. “Despite the concerns, what we hear from our members is that they are really excited about opportunities in the biosimilar space in the coming decade.”

For Tesser, the die has already been cast.

“It is a work in progress that is already started,” he said. “We are past the beginning of the beginning, and are probably entering the middle of the middle. The question is how much longer until we get to the place with biologics where we are with generics. It is not going to be within a year or 2, but it could be within 3 to 5.”

 Aaron Broadwell, MD, can be reached at rheumatology@healio.com.

Alex Keeton can be reached at Alex.Keeton@accessiblemeds.org.

Katie Taylor, CRH-C, CMPM, CRMS, can be reached at kltaylor@SignatureHealth.net.

John R.P. Tesser, MD, FACP, MACR, can be reached at John.Tesser@azarthritis.com.