SAN DIEGO (FRONTLINE MEDICAL NEWS) – If you perceive that the use of biosimilars for rheumatic diseases hasn’t gained the traction one would expect, you’re not alone. In the opinion of J. Eugene Huffstutter, MD, the expected risks of biosimilar products have clinicians concerned, especially when it comes to immunologic characteristics.

“We’ve all had patients on biologics for years: Everything’s fine, but then the patient has an infusion reaction,” Dr. Huffstutter said at the annual meeting of the American College of Rheumatology. “I’ve had it happen with the first infusion of a biologic and I’ve had it with the 20th infusion of that same biologic product. It’s impossible to predict.”

Dr. Huffstutter, a rheumatologist who is clinical assistant professor of medicine at the University of Tennessee, Chattanooga, went on to note that the potency differences between products are another concern. “One of them has to do with mechanical differences,” he said. “I notice that with various lots, some are easier to mix than others. You are going to get some comments from your infusion nurses depending on how easy or how difficult it may be.”

Other unforeseen risks of biosimilars include the impact on pharmacovigilance, manufacturing, and politics. “What if our government says we want to use this agent or that agent? Or, what if it advises everyone to use the bio-originator? Then there are coverage challenges,” he said. “How are the insurance companies going to look at this? Then there are corporate impacts. The companies that make biosimilars have invested a tremendous amount of resources to bring these to market. We have a huge market in the U.S., but the uptake has been very slow. So are they going to say, ‘We’re going to take our resources and do something else?’ ”

Practice protocols for using biosimilars vary depending on your practice environment. For example, if biosimilars are administered by a freestanding practice, “you have to depend a lot on your state laws in terms of what the pharmacist is able to do,” said Dr. Huffstutter, who is also the past president of the Tennessee Rheumatology Society. “What are the patient support programs available for that biosimilar compared with bio-originator? What do the insurance contracts say in terms of can you get this filled or not? What’s the formulary status? How well do physicians in your community accept biosimilars? More importantly, how do your patients feel about biosimilars? I think they’ve been left out of this whole discussion.”

Dr. Huffstutter disclosed that he has received research support from GlaxoSmithKline, Pfizer, and UCB. He is also a member of the speakers bureau and/or is an adviser to Janssen, Lilly, Pfizer, Genentech, Novartis, Regeneron, and UCB.