This article takes the form of a Q&A with pharmacist Dr. Alan Carter. He answered some questions we had about using biologics to treat psoriatic arthritis (PsA).

Biologics are a type of medication that a doctor may prescribe to someone who has moderate-to-severe PsA. Biologics are very effective at reducing inflammation and its potential complications in people with this condition.

Multiple types of biologics can help treat PsA. Each type works in a different way. For example:

Tumor necrosis factor inhibitors

Tumor necrosis factor (TNF) inhibitors and biosimilar products block the inflammatory action of a protein called TNF.

Usually, the body naturally blocks any excess TNF. In people with PsA, however, the amount of TNF in the blood exceeds the body’s ability to block it.

Blocking TNF helps lower inflammation in the skin, joints, and gastrointestinal tract. This reduces pain and irritation, allowing for improved body function and movement.

Interleukin inhibitors

Interleukins (IL) are a class of proteins that help trigger immune responses, such as inflammation. IL-17A, IL-12, and IL-23 act on cells in the blood and joint fluids. They increase inflammatory reactions in the skin and joints.

IL inhibitors reduce the inflammatory effects of these proteins.

T cell inhibitors

T cells are a type of white blood cell. When they become activated, they stimulate an immune response that causes inflammation.

T cell inhibitors block their activation. This helps stop the inflammation that can lead to PsA.

The following sections describe the types of biologic available for PsA.

TNF inhibitors

The Food and Drug Administration (FDA) have approved several types of TNF inhibitor to treat PsA, including:

  • adalimumab (Humira)
  • certolizumab pegol (Cimzia)
  • etanercept (Enbrel)
  • golimumab (Simponi)
  • infliximab (Remicade)

The FDA have also approved several biosimilars of TNF inhibitors to treat PsA, including:

  • Biosimilars of adalimumab (Abrilada, Amjevita, Cyltezo, Hadlima, Hyrimoz): Due to legal action from manufacturers of biologics, these medications have been delayed for release in the United States until 2023.
  • Biosimilars of etanercept (Erelzi, Eticovo): Although they currently have approval, these medications are not available in the U.S. at this time.
  • Biosimilars of infliximab (Avsola, Inflectra, Ixifi, Renflexis): These medications are currently available.

Biosimilar products offer potential cost savings to people.

IL inhibitors

The FDA have approved two types of IL-17A inhibitor and one type of IL-12/23 inhibitor for treating PsA:

  • ixekizumab (Taltz), which targets IL-17A
  • secukinumab (Cosentyx), which targets IL-17A
  • ustekinumab (Stelara), which targets both IL-12 and IL-23

T cell inhibitors

The FDA have also approved one type of T cell inhibitor to treat this condition: abatacept (Orencia).

The section below lists some possible side effects of using biologics for PsA and explores how to manage them:

  • Nausea: To help reduce nausea, a person can eat a light snack and sip fluids slowly until their stomach settles and can tolerate larger amounts of food and liquid. Ginger tea may also help relieve nausea.
  • Pain and swelling at the injection site: To help prevent pain and swelling at the injection site, clean the area beforehand, rotate the injection sites, and numb the skin by applying an ice pack about 15 minutes before each injection. A person should let their healthcare provider know if redness or swelling develops or worsens over time.
  • An increased risk of infection: It is important for anyone who has tuberculosis (TB) or an active or recurrent infection to let their doctor know. To manage the risk of infection, it is vital to maintain a healthful diet and good personal hygiene habits.
  • A reduced ability to make new blood cells: A person should tell their healthcare provider if they experience increased fatigue or weakness. They may order some tests to check the person’s blood cell levels.
  • Liver damage: To monitor for changes in a person’s liver function, a healthcare provider may recommend periodic testing.

If a person is using a biologic for PsA and develops any symptoms of infection — such as a cough, fever, or other flu-like symptoms — they should contact a healthcare provider right away.

When weighing the potential advantages and disadvantages of using biologics to treat PsA, healthcare providers and their patients should consider:

  • the patient’s health history, including any history of TB, any viral illnesses they have, and the general status of their immune function
  • their ability to use an auto-injector to self-inject the biologic correctly, or the availability of someone who can help them inject it
  • the cost of the therapy, whether or not the patient has health insurance coverage for specific biologics, and whether or not the manufacturer offers any patient assistance programs

Some other potential treatment options for PsA include:

  • Nonsteroidal anti-inflammatory drugs (NSAIDs): These medications are the most common first step in treating mild symptoms of PsA. Due to the risk of side effects, however, people should avoid using NSAIDs long-term.
  • Corticosteroids: These medications can provide fast relief from inflammation. However, people should only use corticosteroids short-term, due to the risk of serious side effects associated with prolonged use. That said, they can help reduce symptoms during the time it takes for other treatments to take effect.
  • Nonbiologic disease-modifying antirheumatic drugs (DMARDS): Examples of these drugs include methotrexate, leflunomide, and sulfasalazine.
  • Tofacitinib (Xeljanz): This medication is part of a new class of drugs called janus kinase inhibitors. It is effective in adults with PsA, including those whose bodies cannot tolerate DMARDS.
  • Apremilast (Otezla): This is a phosphodiesterase-4 (PDE4) enzyme inhibitor that blocks the inflammatory effects of the PDE4 enzyme. This can reduce overactive inflammation in people with PsA.

To help manage PsA and promote good overall health, a person should:

  • Eat a diet that contains fruits, vegetables, and fermented foods such as yogurt: These foods contain natural antioxidants, beneficial bacteria, and other compounds helpful for reducing inflammation.
  • Try to get 7–9 hours of restful sleep per day: Good quality sleep helps improve physical function and healing.
  • Get regular exercise: Movement can help loosen the joints, while light weight training can help strengthen the muscles surrounding the joints.
  • Try to reduce stress: Stress can be a trigger for PsA flare-ups, which is why it is important to find time to focus on relaxation.

PsA causes inflammation throughout the body. This can potentially damage a person’s:

  • Bones and joints: Joint damage from PsA can be permanent and may require joint replacement to treat. Having osteoporosis as well as PsA can increase a person’s risk of breaking a bone and slow healing after a break, joint remodeling surgery, or joint replacement surgery.
  • Gastrointestinal tract: PsA involves an increased risk of inflammation in the intestinal tract, which can lead to the development of Crohn’s disease. Symptoms of Crohn’s disease include frequent diarrhea, cramping, pain, and bloody stools.
  • Heart: There is an increased risk of cardiovascular disease in people with PsA. This may be due to the chronic inflammation influencing high blood pressure, obesity, and heightened insulin resistance.
  • Eyes: Eye inflammation can occur in around 7% of people with PsA, with rates among children as high as 17%. If a person develops symptoms such as redness, irritation, pain, or blurred vision that last for longer than 2–3 days, they should consult an eye doctor and inform them that they have PsA.

Getting effective treatment for PsA can help reduce inflammation. This may help lower the risk of complications and provide relief from symptoms.


Alan Carter, Pharm.D., has served as principal investigator for two National Institutes of Health (NIH) drug development programs, directed business strategy and clinical services for a regional pharmacy chain, and conducted medical formulary development and medication therapy outcome evaluations. Dr. Carter has extensive background in both community and hospital clinical practice settings. He is the author of 20 peer reviewed medical publications as adjunct faculty at the University of Missouri-Kansas City (UMKC). Dr. Carter completed both his Bachelor of Science in Pharmacy and Doctor of Pharmacy degrees at UMKC, and he received the university’s 2019 Pharmacy Alumnus Career Achievement Award for biologic insulin research.