The U.S. Food and Drug Administration (FDA) has approvedInflectra– a so-called biosimilar version of the biologicRemicade(infliximab) – to treatrheumatoid arthritis(RA),ankylosing spondylitis(AS) andpsoriatic arthritis(PsA) as well as psoriasis and inflammatory bowel disease. It is the first biosimilar approved in the U.S. for autoimmune, inflammatory conditions, including RA, PsA and AS, and only the second biosimilar approved by the agency to date. (A drug used in cancer treatment, filgrastim-sndz, sold asZarxio2015年3月批准。)
“It is exciting to see more treatment options for people with RA and other inflammatory types of arthritis come to the market,” says Sandie Preiss, the Arthritis Foundation’s vice president of advocacy and access. “These medications are the difference between leading your life as a disabled person and being able to participate in the everyday activities of life.”
What’s a Biosimilar?
Many people are familiar with the concept of generic medication, but biosimilars are not the same as generics. Generics contain the exact chemical copy of the active ingredient in a branded medication, such as atorvastatin, which is genericLipitor, or omeprazole, which is genericPrilosec. A biosimilar is a not-quite-perfect copy of a biologic – a drug that is derived from living cells that are impossible to replicate exactly. Before it is FDA-approved, it must undergo rigorous comparative testing to show it is as safe and effective as the original drug (called reference product).
“A biosimilar that has been approved by a regulatory agency such as the FDA has undergone extensive and rigorous testing comparing it to the reference product, and has been shown to be highly similar structurally and to have not-clinically-meaningful differences from the reference product,” says Jonathan Kay, MD, a professor of medicine and director of clinical research in rheumatology at University of Massachusetts Memorial Medical Center in Worcester, Mass.
Because of that, even if a biosimilar has not been tested on all the conditions for which the reference product is indicated, 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.
The makers ofInflectra, for example, submitted to the FDA results from studies of patients with RA and AS, but not the other conditionsRemicadeis indicated for, including psoriatic arthritis and inflammatory bowel disease. “Studies of patients with rheumatoid arthritis and ankylosing spondylitis show that [Inflectra] performs very much likeRemicade, and we not only have safety data from those studies but also from the experience of countries outside the U.S.,” says Donald Miller, PharmD, a professor of pharmacy at North Dakota State University in Fargo and a member of the Arthritis Advisory Committee to the FDA. (The Arthritis Advisory Committee voted in February to recommend approval ofInflectra, then called CT-P13.)
Leonard Calabrese, DO, vice chair of rheumatic and immunologic diseases at Cleveland Clinic, who has written extensively on biosimilars, says that he is “very confident from the data I have seen that [Inflectrais] effective and appears to be safe.” He says he would have no problem starting patients on it or switching patients to it when it becomes available.
But other doctors may not be that quick to jump on the bandwagon– at least not without more education on the subject. According to one survey of 300 primary care doctors and specialists – conducted by QuantiaMD, a doctor platform and community –78% of the doctors surveyed said they were familiar with the term “biosimilar,” but only 17% of those deemed by QuantiaMD most-likely to prescribe biosimilars said they were “very likely” to do so. Another survey of 405 pharmacists and doctors, conducted by NACCME, a continuing medical education company, found that 75 percent of respondents felt that continuing education on biosimilars was important or very important to their practice.
Greater Access For Patients
Patients, doctors and patient-advocacy groups like the Arthritis Foundation hope that biosimilars will lower the cost of biologic medications by making them more accessible. Biologics are expensive, and many patients, even those who are insured, incur high out-of-pocket costs. Because biosimilar manufacturers don’t have the research and development costs associated with a new drug, the expectation is that they will be sold more cheaply. Experts predict that in the U.S. they will cost about one-third less than the originals, but no one knows for sure yet. Dr. Kay notes that in countries where pharmaceutical companies bid for contracts for hospital-administered drugs, the cost forInflectrais as much as 71 percent lower than the original cost forRemicade.
Competition from biosimilars may drive down the price of branded biologics, too, although that’s not a given, says Eric Matteson, MD, rheumatology chair at Mayo Clinic in Minnesota.
The price ofInflectra, manufactured by South Korea-based Celltrion, Inc. for Hospira (now part of Pfizer Inc.) has not yet been made public.
But biosimilars aren’t without controversy. They still face some outstanding issues, such as what to name the new drugs. In accordance with FDA draft guidance (which has not been finalized yet),Inflectrais known as infliximab-dyyb to differentiate it from the reference product infliximab (Remicade).The names need to be unique for ordering, prescribing and record-keeping purposes. Another issue is what information is contained in the package insert (the “label information”). The FDA released the draft guidance for biosimilar labeling earlier this month.
Biosimilar versions of biologics used for RA, AS and PsA are already in use in countries in Europe and Asia, as well as in Canada and Australia, among others. In the U.S., you can expect to see more biosimilars come to market in the coming years as drug patents for popular biologics expire. A few have already been submitted to the FDA for approval, including biosimilar versions of adalimumab (Humira) and etanercept (Enbrel).
Authors: Linda Rath, Mary Anne Dunkin & Andrea Kane
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