The U.S. Food and Drug Administration (FDA) on Friday approved the third biosimilar to treat inflammatory types of arthritis – but, like the two that were previously approved, this one will not be available to patients until patent disputes are resolved.
Adalimumab-atto (brand name Amjevita) is a biosimilar to the blockbuster drug adalimumab (Humira). It was approved to treat adults with rheumatoid arthritis (RA), ankylosing spondylitis (AS), psoriatic arthritis (PsA), psoriasis, Crohn’s disease and ulcerative colitis. It was also approved to treat children age 4 and older with polyarticular juvenile idiopathic arthritis (pJIA).
The approval of adalimumab-atto follows the August approval of etanercept-szzs (Erelzi), a biosimilar to etanercept (Enbrel), and the April approval of infliximab-dyyb (Inflectra), a biosimilar to infliximab (Remicade). Biosimilars, including those for inflammatory conditions like RA, are already on the market in countries in the European Union and several others, including Canada, Australia, Japan, South Korea. The first biosimilar approved in the United States was a drug that is used during cancer treatment. Unlike Inflectra, Erelzi and now Amjevita, it is available commercially to patients.
“I am glad that we have yet another biosimilar TNF inhibitor approved for the treatment of RA and other inflammatory diseases,” says Jonathan Kay, MD, a professor of medicine at University of Massachusetts Medical School and the director of clinical research in rheumatology at UMass Memorial Medical Center, both in Worcester, Mass.
Biosimilars are so-called copycat versions of biologic medications used to treat serious diseases such as cancer and rheumatoid arthritis. They are expected, much like generic drugs, to be less expensive than the original drug (called a “reference product”).
But they are not generics. Generics are exact copies of chemically synthesized medicines, such as aspirin or antacids. Biosimilars are not-quite-precise copies of biologics – drugs derived from living organisms (including cells from humans, animals, microorganisms or yeast) that are impossible to replicate exactly.
Because biosimilars are so complicated to manufacture, they have their own approval process (or pathway) within the FDA and their own naming convention. “The biosimilar pathway is still a new frontier and one that we expect will enhance access to treatment for patients with serious medical conditions,” says Janet Woodcock, MD, director of the FDA’s Center for Drug Evaluation and Research, in a press release.
Approval depends on rigorous comparative testing that demonstrates the biosimilar is “highly similar” to the reference product in terms of safety, purity and potency as well as possessing the same structural and functional characteristics.
“Biosimilars have the same amino acid sequence as biologics; the potency, dosing, route of administration and clinical effects are identical. The ways in which they differ aren’t significant,” explains Dr. Kay.
In accordance with FDA guidance, the name of a biosimilar needs to be unique for ordering, prescribing and record-keeping purposes. Amjevita is known as adalimumab-atto – the core name plus a unique four letter suffix – to differentiate it from the reference product adalimumab (Humira).
Even before FDA approval of Amjevita, Humira’s maker, AbbVie, sued Amgen, the biosimilar maker, for patent infringement. Legal challenges, like this one and the ones Erelzi and Inflectra face, can keep new products off the market, even after FDA approval, until the suit is resolved.
“If we care about our patients and we want effective medications available at affordable costs, the FDA approval process allows for marketing of these medications,” says Dr. Kay. “However if the manufacturer of the bio-originator [the reference product] chooses to try to defend their patent, this delays the commercial availability of the biosimilar until the courts rule.”
In August, a federal court in Boston invalidated a key patent on Johnson & Johnson drug’s infliximab (Remicade), increasing the odds that Pfizer can bring infliximab-dyyb (Inflectra) to market sooner rather than later. Johnson & Johnson said it would appeal.
Author: Andrea Kane for the Arthritis Foundation
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