What Are Biosimilars?
Reviewed by: HU Medical Review Board | Last reviewed: March 2022 | Last updated: November 2022
Biosimilars are a type of drug that may be an option for some people with rheumatoid arthritis (RA). They may be able to replace the biologics that are often used to treat RA.1
Biosimilars are safe and effective. Like all drugs, they must undergo rigorous testing in clinical trials before they receive approval from the U.S. Food and Drug Administration (FDA).1
What is a biosimilar?
Biosimilars are drugs that are a type of biologic therapy. Biosimilars are named for the fact that they are very similar to an already-approved biological product. You can think of biosimilars as a “copycat” of biologics. They are not exactly the same as the biologic. But they are similar enough to be approved for all the same uses as the biologic.1
Like biologics, biosimilars have bioengineered proteins. These proteins mimic certain functions in human genes or cells, and they are made from living cells. Biologics are used to reduce or better regulate the inflammatory response, which is overactive in conditions like RA.1,2
Below is a list of biosimilars for RA and their reference products.
Biosimilars to Humira® (adalimumab):3,4
Biosimilars to Enbrel® (etanercept):3,4
Biosimilars to Remicade® (infliximab):3,4
Biosimilars to Rituxan® (rituximab):3,4
The difference between a biologic and biosimilar
Biologics and biosimilars are not identical. But to be approved by the FDA, biosimilars need to produce no significant differences in safety and efficiency compared to the biologic. Biosimilars must have the same mechanism of action, route of administration, strength, and dosage form as their reference product. Biologics must also have no significant differences in purity and potency.1-3
If a biosimilar meets all of these requirements and produces the same clinical result as its reference product, it can be approved by the FDA.1-3
The difference between a biosimilar and a generic
Biosimilars are not the same as generics. Generics have the same chemical structure and are exact copies of a reference medicine. Biosimilars are not exactly like their reference biologics.2
Like generics, they are generally cheaper than the reference medicine. In many states, pharmacists can interchange a generic medicine for the reference drug without telling the prescribing doctor. This is not yet allowed for biosimilars.2
Things to know
One concern about biosimilars would arise if the FDA decides they are interchangeable with the branded biologic. If this happened, pharmacists could switch them out with biologics without informing doctors or the people taking them. This is not yet an issue. But some states are passing or considering laws concerning substitutions to prevent this problem.1
Another issue with biosimilars is that not all approved drugs are available in the United States. While the FDA has approved many biosimilars, most are not yet available to consumers. Many are tied up in lawsuits with the biologic companies.1,2
Biologics can be very expensive. A big benefit of biosimilars is that they cost a lot less than biologics. However, it is not certain that they will cost consumers less out of pocket. Any potential savings will depend on insurance companies’ policies.1,3
If you take a biologic and are interested in its biosimilar, talk with your doctor. Your doctor will be able to discuss the pros and cons with you and address any questions or concerns.1