Biosimilar Drugs for Psoriatic Arthritis
One common treatment for psoriatic arthritis (PsA) is disease-modifying anti-rheumatic drugs (DMARDs). DMARDs reduce inflammation. They can also help prevent long-term joint damage, which can cause disability.
There are different types of DMARDs. These are:
- Traditional (or non-biologic)
Biologic DMARDs (or “biologics”) are often used in moderate-to-severe PsA. Biologics are also used when a person’s PsA has not improved with other treatment options. They can be used on their own or alongside other PsA treatments like phototherapy. Biosimilars are a type of biologic treatment.1,2
How do biologics work?
Biologics are drugs that have very specific targets in the body. They are proteins made in a lab from living cells. In PsA, biologics target parts of the immune system. Some target cytokines like tumor necrosis factor-alpha (TNF-alpha). Cytokines are proteins that play a role in inflammatory response. When they are blocked, inflammation may be slowed or stopped. This is helpful for autoimmune or inflammatory conditions like PsA. Decreasing inflammation can help improve symptoms and prevent further joint damage.1,2
What is a biosimilar?
Since biologics are made from living cells through a complicated process, they are hard to copy and expensive. Given the success of common biologics, other companies have started to make similar drugs. In these cases, a Food and Drug Administration-approved biologic can serve as a reference product. New biosimilars can be compared with the reference product for safety, efficacy, and clinical outcomes.3
Since it is impossible to perfectly copy living cells, the goal is to create something very close. For a new drug to be considered a biosimilar, it must be deemed “highly similar” by the FDA.3 The FDA compares the ingredients and structures of both drugs to look for any major differences. Also, a biosimilar must have “no clinically meaningful differences” from its reference product. This means the overall effectiveness of the biosimilar is the same as the reference product.1-3
Biosimilars can be evaluated further to be considered interchangeable products. This means the biosimilar and its reference product produce the same response in any given person. The ability to switch back and forth between interchangeable products is also studied. Interchangeable products can be substituted without a doctor’s approval.1,3
Are biosimilars the same as generics?
Biosimilars and generics are approved more quickly to provide cheaper options to those who need them. However, generics are true copies of their brand-name counterparts. Unlike biologics made from living cells, other drugs can be copied ingredient for ingredient. Biologics will always have some differences depending on how they are made. Because of this, biosimilars are not generics.1,3
Examples of biosimilars for PsA
Though all may not be available, a variety of biosimilars exist for PsA. These can be separated into groups based on their reference products. All listed examples target TNF-alpha, like their reference products.
Examples of biosimilars to Humira® (adalimumab) include:1
- Amjevita™ (adalimumuab-atto)
- Cyltezo® (adalimumab-adbm)
- Hadlima™ (adalimumab-bwwd)
- Hulio® (adalimumab-fkjp)
- Hyrimoz™ (adalimumab-adaz)
Examples of biosimilars to Enbrel® (etanercept) include:1
- Erelzi™ (etanercept-szzs)
- Eticovo™ (etanercept-ykro)
Examples of biosimilars to Remicade® (infliximab) include:1
- Inflectra® (infliximab-dyyb)
- Ixifi™ (infliximab-qbtx)
- Renflexis™ (infliximab-abda)
- Avsola™ (infliximab-axxq)
What are the possible side effects of biosimilars?
Side effects can vary depending on the biosimilar drug you are taking. Some of the most common side effects are:4-6
- Upper respiratory infection
- Sinus infection
- Sore throat
- Abdominal pain
- Infusion or injection site reactions (redness, itching, swelling)
These are not all the possible side effects of biosimilars for PsA. Talk to your doctor about what to expect or if you experience any changes that concern you during treatment.
Things to know about biosimilars
Because they reduce inflammation and immune system response, biosimilars can increase the risk of infection. Serious infections can be caused by fungi or bacteria and become life-threatening. Do not start taking a biosimilar for PsA if you have an active infection, pregnant or breastfeeding.
Before you start a biosimilar, your doctor may test you for tuberculosis (TB) and hepatitis B. Starting a biosimilar when you have TB or hepatitis B can lead to severe infection. If you are at high risk for infection on a biosimilar, you may need to take other drugs alongside it. If you get fevers, chills, muscle aches, or other symptoms of an infection, talk with your doctor right away.
In some cases, biosimilars for PsA may impact a person’s blood cell counts or increase the risk of cancer. Your doctor can tell you if your drug has those risks.
Before beginning treatment for PsA, tell your doctor about all your health conditions and any other drugs, vitamins, or supplements you are taking. This includes over-the-counter drugs, as many biosimilars can interact with other drugs. Although it is rare, serious allergic reactions can occur with biosimilars. Tell your doctor about any allergic reactions you have had to drugs in the past. Signs of an allergic reaction include hives, trouble breathing, abdominal pain, and swelling of the face, tongue, or lips.
Biosimilars can also impact a person’s ability to safely receive live vaccines. However, most vaccines are not live and can still be taken. Talk with your doctor before starting a biosimilar if you recently received or will soon receive a vaccine.4-6