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Biosimilars FAQs

Biologics and biosimilars can help patients with moderate to severe inflammatory bowel disease (IBD). But you might have questions about how these drugs work. AGA provides answers to frequently asked questions (FAQs) that you might have about biologics and biosimilars.
What are biologics?
Biologics are a type of drug used to treat disease. Most drugs are made using simple chemical processes. Biologics, on the other hand, are large and complex, are derived from living organisms, and are made by complicated manufacturing processes using cutting-edge technology.
What are biosimilars?
Biosimilars are highly similar to, but not exact copies of, existingbiologics.
How does a biosimilar differ from the original biologic?
A biosimilar differs very slightly from the original biologic, only because the way biologics and biosimilars are made is so complex. It is not possible to make an exact copy of a biologic. However, the biosimilar is given the same way and at the same strength and dose as the original biologic. And, the company that makes the biosimilar tests it in people (in clinical trials) to make sure it has no clinically meaningful differences from the original biologic.
Are biosimilars like generic drugs?
Biosimilars are not generics but they are alike in the sense that they: 1) are both versions of “brand name” drugs, 2) may cost less, and 3) become available after the original drug loses its exclusive patent. Biosimilars and generics are also both approved through shorter pathways that avoid duplicating costly clinical trials. Generics and biosimilars are different in that generics are exact copies of drugs with known chemical structures, while biosimilars—because they are large and complex proteins—may differ slightly in their structure from the biologics they are based on (but not in a way that affects their function).
How do we know biosimilars work? What standards are there and what kind of testing is done?
The U.S. Food and Drug Administration (FDA) requires many tests to show that a biosimilar is highly similar to the original biologic. Before a biosimilar is made available, it must clear these hurdles:
  • Studies must show it works the same as the original biologic — with no clinically meaningful differences in terms of how well it works and how safe it is.
  • It must be available in the same forms and doses as the original biologic.
  • It can only be used to treat the diseases that the original biologic is used for.
How long will it take before I know whether a biosimilar is working for me?
If you are starting a biosimilar without ever having tried the original biologic, ask your gastroenterologist about the timeframe he/she has in mind for looking at how this new treatment is working for you. If you’re switching from the original biologic to a biosimilar, there’s no reason to think that the biosimilar won’t work the same as the original biologic. But, let your doctor know if you have any concerns.
What is the difference in cost between the original biologic and a biosimilar?
For insurance companies, hospitals and people paying for their own medicines, there may be savings using a biosimilar instead of the original biologic. People with insurance may not see any difference.
What does interchangeability mean?
Interchangeability means that even though the original biologic and the biosimilar are not exactly the same, either can be used and the same results will be expected. A pharmacist can give a patient an interchangeable drug without asking the health care provider who wrote the prescription if it’s OK, though different states may have different rules about this. As of late 2019, FDA had not approved any biosimilars as interchangeable. In the future, some biosimilars may be called interchangeable after they pass through more testing. This would include clinical studies showing that switching multiple times between different biosimilars and the original biologic does not affect the safety or effectiveness of the products. All approved biosimilar drugs, whether or not they are designated interchangeable, meet the FDA’s high standards.
Is it OK to switch from the original biologic to a biosimilar?
Research says yes. You should be able to switch from the original biologic to a biosimilar without problems. Your disease signs and symptoms should still be controlled in the same way, and you should not have any new side effects from the biosimilar.
How does my doctor decide whether to prescribe the original biologic or a biosimilar?
Different doctors make different decisions—there is no one right answer or way to decide. Being familiar with biosimilars and the studies that support them may play a role in your doctor recommending one. Insurance coverage or health care network policy may also be looked at. Your preference will also be considered if you are willing to pay for a drug if insurance won’t cover it.
What happens if I don’t do well on a biosimilar?
Research suggests that if you do well on the original biologic, you will do well on a biosimilar. If that turns out not to be the case, it could be due to a disease flare or an infection unrelated to the biosimilar. Or, symptoms could be due to something called a “nocebo” effect, which means that if you are anxious that you might do poorly on a drug, that could come to pass. Your doctor can work with you to figure out if you are having a true flare, if your symptoms are due to some other medical reason, or if concerns about the biosimilar are behind what’s going on. If a biosimilar is your first biologic drug, your doctor will measure how well it works the same as he/she would with any other biologic.
Do biosimilars work as well as the original biologics?
Research says yes. There’s no reason to think they won’t work just as well.
Are biosimilars as safe as the original biologics?
Research says yes. There’s no reason to think they won’t be just as safe.
Are there any biosimilars available for my doctor to prescribe?
Yes. Several biosimilars are already available—and more are likely coming.
What does “reference” or “originator” biologic or product mean?
You may hear a biologic called the “reference” or “originator” biologic or product. That means it was the initial or original (first) biologic drug of its type approved by the FDA. These are the medicines that biosimilars are modeled after.
How often will I have to be treated with a biosimilar?
The frequency of treatment will be the same with the original biologic and the biosimilar.
Are there any benefits to being treated with a biosimilar?
Research shows there are no drawbacks, but there are likely also no added benefits. Biosimilars may cost less than biologics, but you may not see those savings. This activity was supported by an independent educational grant from Pfizer.

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