The Arthritis Advisory Committee to the Food and Drug Administration (FDA) voted 21 to 3 on Tuesday (Feb. 9) to recommend approval of CT-P13, a biosimilar version of Remicade (infliximab), which is used to treat inflammatory types of arthritis, including rheumatoid arthritis (RA), psoriatic arthritis (PsA) and ankylosking spondylitis (AS). CT-P13 is the first biosimilar to treat arthritis to reach this milestone.
Similar but not identical
A biosimilar is highly similar to, but not exactly the same as the existing, FDA-approved biologic, called the “reference” drug (in this case Remicade). People are familiar with generic versions of brand-name drugs, but biosimilars are not generic drugs. Generic versions of brand-name drugs are exact copies of chemically synthesized medicines. Biosimilars are not-quite-perfect copies of biologics – drugs derived from living cells that are impossible to replicate exactly.
That goes to the heart of some people’s concerns about biosimilars. Numerous biosimilars, including CT-P13 (which is sold as Remsima and Inflectra, depending on the country), have already been approved in Europe, Japan and elsewhere. But so far in the United States, only one biosimilar – a drug used during cancer treatment – has been approved. The first questions about these drugs concern safety and efficacy. Before submission to the FDA, a biosimilar has to go through rigorous comparative tests to show it’s as safe, pure and effective as the reference drug.
CT-P13 was tested in patients with RA and AS, but not the other conditions Remicade is indicated for (including psoriatic arthritis and inflammatory bowel disease). “Studies of patients with rheumatoid arthritis and ankylosing spondylitis show that [CT-P13] performs very much like Remicade, and we not only have safety data from those studies but also from the experience of countries outside the U.S.,” says advisory committee member Donald Miller, Pharm D, a professor of pharmacy at North Dakota State University, in Fargo.
Even if a biosimilar has not been tested on all the conditions the reference product is indicated for, the FDA previously decided that a biosimilar could be approved for all of those, too – as long as it works via the same mechanism in those diseases.
One anticipated benefit of biosimilars: They are expected to reduce health care spending overall, with potentially significant savings for individuals. Branded biologics – with price tags that can range anywhere between $20,000 and $50,000 a year and can carry high out-of-pocket costs for patients – are among the most expensive drugs. It’s not known what CT-P13 will cost, but Miller and other experts predict it will be about 20 to 30 percent less than Remicade.
“Biosimilars offer a good opportunity for patients to save money,” says Miller. “I suggest they have a serious conversation with their doctor as to whether a biosimilar might be appropriate for them.”
Miller predicts the FDA will approve the drug soon, perhaps within a couple of months. (The FDA doesn’t have to follow its advisory committee’s recommendations, but it usually does.) If so, that would make CT-P13 the first arthritis biosimilar in the U.S.
But even with FDA approval, CT-P13 may face an uphill battle getting to the marketplace. The makers of Remicade and CT-P13 are already engaged in legal skirmishes, potentially delaying its availability. Similarly, biosimilars for Humira (adalimumab) and Enbrel (etanercept), if eventually approved (both have already filed for FDA review), may get tied up in court as well.
Author: Linda Rath for the Arthritis Foundation