Biosimilar Drugs for Psoriatic Arthritis

Disease-modifying antirheumatic drugs (DMARDs) are a common treatment for psoriatic arthritis (PsA). DMARDs reduce inflammation. They can also help prevent long-term joint damage, which can cause disability.^1,2

There are different types of DMARDs. These include:^1,2

• Traditional (or non-biologic)
• Biologics and biosimilars
• Target-specific

Biologic DMARDs (or “biologics”) are often used to treat 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 very similar to biologics, with the same clinical effectiveness, but less expensive.^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 people with PsA, biologics target parts of the immune system. Many of these drugs target cytokines like tumor necrosis factor-alpha (TNF-alpha).^1,2

Cytokines are proteins that play a role in the inflammatory response. When these proteins are blocked, inflammation may slow or stop. This is helpful for people with 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 and expensive to copy. Given the success of certain common biologics, other companies have started to make drugs that are similar to them. These drugs are called biosimilars.³

In these cases, a biologic that is already approved by the US Food and Drug Administration (FDA) serves as a reference product. Biosimilars are compared with the reference product for safety, efficacy, and clinical outcomes.³

Since it is impossible to perfectly copy living cells, the goal for a new biosimilar drug is to create something very close to its reference product. For a new drug to be considered a biosimilar, it must be deemed “highly similar” to its reference drug 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

Interchangeable products

With further evaluation, a biosimilar can become classified by the FDA as an interchangeable product. This means the biosimilar and its reference product produce the same response in any given person. Experts study people’s ability to switch back and forth between interchangeable products to make sure the drugs have the same effect.^1,3

Interchangeable products can be substituted for their reference product without a doctor’s approval in some states.^1,3

Are biosimilars the same as generics?

Biosimilars and generics are approved more quickly to provide cheaper options to people who need them. However, generics are chemical copies of their brand-name counterparts, while biosimilars are not an exact copy. However, biosimilars are highly similar to their reference biologics and have been proven to have the same effects.^1,3

Biosimilars will always have slight differences from their reference products, depending on how they are made. Because of this, biosimilars are not generics.^1,3

Examples of biosimilars for PsA

Though not all may be available, a variety of biosimilars exist for PsA. Below, examples are grouped based on their biologic reference product. All biosimilars listed below target TNF-alpha, except for Wezlana™. It instead targets the cytokines interleukin 12 (IL-12) and interleukin 23 (IL-23).^4-7

Examples of biosimilars to Humira® (adalimumab) include:⁴

• Abrilada™ (adalimumab-afzb)
• Amjevita™ (adalimumab-atto)
• Cyltezo® (adalimumab-adbm)
• Hadlima™ (adalimumab-bwwd)
• Hulio® (adalimumab-fkjp)
• Hyrimoz® (adalimumab-adaz)
• Idacio® (adalimumab-aacf)
• Yuflyma® (adalimumab-aaty)
• Yusimry™ (adalimumab-aqvh)

Examples of biosimilars to Enbrel® (etanercept) include:⁵

• Erelzi™ (etanercept-szzs)
• Eticovo™ (etanercept-ykro)

Examples of biosimilars to Remicade® (infliximab) include:⁶

• Inflectra® (infliximab-dyyb)
• Ixifi™ (infliximab-qbtx)
• Renflexis™ (infliximab-abda)
• Avsola® (infliximab-axxq)

Examples of biosimilars to Stelara® (ustekinumab) include:⁷

• Wezlana (ustekinumab-auub)

What are the possible side effects?

Side effects can vary depending on the biosimilar drug you are taking. Some of the most common side effects of biosimilars for PsA are:^8-11

• Upper respiratory infection
• Sinus infection
• Sore throat
• Headache
• Fatigue
• Abdominal pain
• Rash
• Infusion or injection site reactions (redness, itching, swelling)

Like their reference products, biosimilars to Humira, Remicade, and Enbrel each have a boxed warning, the strictest warning from the FDA. They have this warning because they may increase the risk of serious infections and certain cancers.

These are not all the possible side effects of biosimilars for PsA. Talk to your doctor about what to expect when taking biosimilar drugs. You should also call your doctor if you have any changes that concern you when taking a biosimilar.

Other things to know

Because they reduce inflammation and immune system response, biosimilars can increase your 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. If you are pregnant or breastfeeding, you should not take most biologics; your doctor can tell you which medications are safe for you.^8-11

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 have fevers, chills, muscle aches, or other symptoms of an infection, talk with your doctor right away.^8-11

In some cases, biosimilars for PsA may impact blood cell counts or increase the risk of heart failure or cancer. Your doctor can tell you if your drug has those risks.^8-11

While 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.^8-11

Biosimilars can also impact your 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.^8-11

Many biosimilars can interact with other drugs. 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.