Which biologic is best for psoriatic arthritis?
Psoriatic arthritis (PsA) is a chronic autoimmune condition — it causes the immune system to attack joints and, sometimes, other tissues. PsA usually develops in people who already have the skin condition psoriasis.
“As we see newer epidemiology studies, we’re beginning to realize that the disease is more common than we thought, historically,” Dr. Philip Mease, a clinical professor at the University of Washington School of Medicine and the Director of Rheumatology Research at Swedish medical Center, in Seattle, told Medical News Today.
Biologics for psoriatic arthritis: Everything you need to know
“Psoriasis is a relatively common condition that occurs in up to about 3% of the population,” he continued, “and we think that PsA then occurs in up to about 30% of those patients.”
A person with PsA may develop inflammation in any joint. The inflammation may also occur where tendons or ligaments attach to bones, an issue that doctors call enthesitis. In addition, PsA can affect the skin, nails, or both.
To help reduce the disease activity and slow the progression of PsA, rheumatologists prescribe medications known as disease-modifying antirheumatic drugs (DMARDs).
Historically, methotrexate was often the DMARD of choice. It is a traditional drug that targets the entire immune system. In recent years, however, biologic DMARDs have played an increasing role in PsA treatment.
Biologics are a type of targeted drug made from genetically engineered proteins. They reduce inflammation by blocking the action of specific proteins or cells in the immune system.
This article provides an overview of the available biologics that can help treat PsA. It also describes the strategies that doctors may use to manage the risk of side effects.
What types of biologics can treat PsA?
The Food and Drug Administration (FDA) have approved several biologics to treat PsA. These medications fall into four categories:
- tumor necrosis factor (TNF) inhibitor
- interleukin-17 (IL-17) inhibitor
- interleukin-12/23 (IL-12/23) inhibitor
- T-cell blocker
A person with PsA may have to try multiple biologics to find the type that works best for them. If one drug is ineffective or causes any disruptive side effects, the doctor may prescribe another type of biologic or a nonbiologic DMARD.
“There is no single biologic agent that is best for everyone with PsA,” Dr. Brett Smith — a rheumatologist at Blount Memorial Physicians Group, in Maryville, TN, and the East Tennessee Children’s Hospital, in Knoxville, told MNT.
“I would encourage patients to speak with their rheumatologist about options for treatment and which drugs may be appropriate for them,” Dr. Smith continued.
Compared with conventional DMARDs, biologics are often “far superior,” in terms of reducing inflammation, swelling, and pain, Dr. Smith said. He added that many people find the side effects of biologics to be easier to tolerate than those of methotrexate.
In rare cases, however, biologics can cause severe side effects. Also, because they are relatively new forms of treatment, data regarding the safety of long-term use have been limited.
“We do not have very long-term data yet,” Dr. Rajat Bhatt, a rheumatologist at Prime Rheumatology, in Richmond, TX, explained. “There might be unknown risks.”
For most people with active PsA, TNF inhibitors are the first line of treatment recommended by the American College of Rheumatology and National Psoriasis Foundation.
The FDA have approved the following TNF inhibitors for treating PsA:
- adalimumab (Humira)
- certolizumab pegol (Cimzia)
- etanercept (Enbrel)
- golimumab (Simponi, Simponi Aria)
- infliximab (Remicade)
If a person is taking Remicade or Simponia Aria, they will visit their doctor’s office or an infusion clinic to receive the drug by intravenous infusion — an IV.
Other types of TNF inhibitors are injected under the skin.
How they work
In people with PsA, the body produces too much of a protein that drives inflammation — called TNF-alpha — in the skin or joints.
TNF inhibitors help block the production of this protein, which can thereby reduce inflammation.
According to a summary of evidence published in Expert Review of Clinical Pharmacology, clinical trials have shown that all five types of TNF inhibitors can limit the progression of PsA.
TNF inhibitors suppress the immune system. As a result, they raise the risk of infection, such as influenza or sinus infection.
Other potential side effects of TNF inhibitors include a rash, headaches, nausea, and pain and swelling at the injection site.
In rare cases, people taking TNF inhibitors have experienced more severe adverse effects, including:
- serious allergic reactions
- serious infections
- liver problems
- nervous system problems
- lupus-like syndrome
- a low blood count
- lymphoma and other types of cancer
- heart failure