Biologic and Biosimilar Drugs
Reviewed by: HU Medical Review Board | Last reviewed: January 2023
Axial spondyloarthritis (axSpA) is a long-term condition with no cure. But treatments such as getting regular exercise and taking medicines can help you manage it.1
Biologic and biosimilar drugs are relatively new types of disease-modifying antirheumatic drugs (DMARDs). These drugs can help reduce inflammation, control pain, and slow the condition's progression. Biologic DMARDs are usually prescribed if other treatments have not helped or if your axSpA is very active.1
What are biologics and biosimilars?
Biologics are drugs made from living cells. These cells might come from blood, viruses, or other parts of the body. This makes biologics different from traditional drugs, which are made in a lab from chemicals instead of directly from living cells.2
Biosimilars are like biologic drugs, but they are made differently. Each biosimilar is highly similar to a biologic drug called its reference drug. Although there are differences, you can think of biosimilars basically as generic versions of biologic drugs.2
Biosimilar drugs must meet the US Food and Drug Administration (FDA) standards of a biologic. They must have the same effect, safety, and effectiveness as their reference drug.2
Biosimilars are usually cheaper than biologics. Because of their lower cost, biosimilars are often more accessible to people with axSpA. In some states, pharmacists can switch your prescription from a biologic to a biosimilar without a doctor's approval. This can be helpful if you cannot afford the more expensive biologic.2
How do biologics and biosimilars work?
Both biologics and biosimilars work on certain aspects of the immune system that affect inflammation. Each type of biologic and biosimilar drug works slightly differently. But most of these drugs work by blocking parts of the immune system to slow its attack on your joints and spine.3
These drugs are proteins, so they cannot be taken as tablets. They have to be injected into the skin.3
Examples of biologic and biosimilar drugs
Several biologics and biosimilars are approved in the United States to treat axSpA. They include:1,4
- Adalimumab (Humira®)
- Certolizumab pegol (Cimzia®)
- Etanercept (Enbrel®)
- Golimumab (Simponi® and Simponi Aria®)
- Infliximab (Remicade®)
- Infliximab-abda (Renflexis®)
- Infliximab-axxq (Avsola®)
- Infliximab-dyyb (Inflectra®)
- Ixekizumab (Taltz®)
- Secukinumab (Cosentyx®)
Some of these drugs are used only for axSpA that is visible on X-ray. This form of axSpA is known as radiographic axSpA or ankylosing spondylitis (AS). Talk to your doctor about which treatment is best for you.1
A few biosimilars have been approved by the FDA but are not yet available in the United States. Your doctor will be able to tell you which ones are available.1
What are the possible side effects?
Many people have little to no side effects from biologics and biosimilars. But all medicines have possible side effects. Side effects can vary depending on the specific drug you are taking. The most common side effects of biologics for axSpA include:5
- Injection site reactions, including redness, swelling, pain, or itching where the shot was given
Several biologic and biosimilar drugs used to treat axSpA have a boxed warning, the strictest warning from the FDA. They have this warning because they can increase your risk of serious infections and certain cancers.6
These are not all the possible side effects of biologics and biosimilars. Talk to your doctor about what to expect when taking these drugs. You also should call your doctor if you have any changes that concern you when taking them.
Other things to know
Before beginning treatment for axSpA, tell your doctor about all your health conditions and any other drugs, vitamins, or supplements you are taking. This includes over-the-counter drugs. Also tell them whether you are or plan to become pregnant.
Your doctor will do regular blood tests and checkups while you are taking a biologic or biosimilar drug. Keep your appointments with your doctor to ensure the drug works as intended.5
Some people may need to take these drugs over a long period of time. Not only do these drugs take time to start working, but it can take your body a while to get used to them.5
Do not stop taking a biologic or biosimilar without talking to your doctor first. Quitting can cause your axSpA symptoms to worsen.5
Biologics and biosimilars can be expensive. Talk with your doctor about any financial assistance programs that may be available.7
Finally, many of these drugs are available for you to take at home. Your doctor's office or nurse can show you how to safely and correctly take your dose.5