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Psoriasis Patients Need to Weigh Infection Risk With Benefits of Biologics

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Key Takeaways

  • Biologic drugs suppress the immune system and are game-changing treatments for psoriasis and psoriatic arthritis.
  • However, these medications can lead to an increased risk of developing serious infections—a risk that is highest in the first year that a person uses a biologic.
  • A recent study in France found that the increased risk of an infection serious enough to require hospitalization varied by which biologic was used.

When biologic drugs used to treat psoriasis, an autoimmune disease that causes scaly, itchy patches on the skin, were first approved in the early 2000s it marked an important advancement for psoriasis patients. Now, new research is highlighting the risks associated with using some of these drugs.

For a July study, a team of researchers in France evaluated the risks associated with several biologic drugs that are used to treat psoriasis. They found that the risks of developing a serious infection— defined as an infection that required hospitalization—were higher with two biologics: adalimumab, and infliximab.

While biologics can reduce psoriasis symptoms, they also suppress the immune system. This puts psoriasis patients at an increased risk of developing infections—which can be serious or even life-threatening.

August is Psoriasis Action Month, a time when organizations raise awareness about the disease and its treatment options.

Infection Risks

For the study, researchers evaluated data from 44,239 people with psoriasis who were new users of biologics over a period of just over 10 years.

During that time, 1,656 patients developed an infection that was serious enough to require hospitalization. The most common type of infection was gastrointestinal infections, followed by skin infections and pulmonary infections.

The researchers, led by Laetitia Penso of Université Paris-Est Créteil, determined that the overall incidence rate for all serious infections was 25 per 1,000 person-years.

A person-year is the equivalent of one patient who takes a drug for one year; therefore, ten person-years could be one person who took the drug for ten years or ten people who took the drug for one year or a similar combination.

The infection rate varied between drugs evaluated. The researchers found that infection risk was lower for ustekinumab (brand named Stelara) but was similar for secukinumab (Cosentyx), ixekizumab (Taltz), brodalumab (Siliq), guselkumab (Tremfya), or apremilast (a nonbiologic drug brand named Otezla) versus etanercept (Enbrel).

Patients who were new users of adalimumab (Humira) or infliximab (Remicade) appeared to be at increased risk for serious infection compared to those using etanercept.

Two drugs—guselkumab (Tremfya) and apremilast—were not associated with an increased risk for serious infection unless the patient was also taking nonsteroidal anti-inflammatory drugs (NSAIDs) or systemic corticosteroids.

In a similar study published online in 2019, G. Caleb Alexander, MD, professor of epidemiology and medicine at the Johns Hopkins Bloomberg School of Health, and his colleagues evaluated the risk of infections that required hospitalization in patients who used biologics for the treatment of psoriasis or psoriatic arthritis.

The researchers compared the risks for two interleukin-17 inhibitors, an interleukin-12/23 inhibitor, and five different tumor necrosis factor inhibitors.

The research showed 190 serious infections in 9264 person-years of treatment—an incidence rate of about 2%. The most common infection was sepsis caused by unspecified organisms, followed by pneumonia, urinary tract infections, and skin infections.

It's important to note that the study by Penso and colleagues was done in France where biologics have slightly different indications or approved usages than they do in the United States. Joel Gelfand, MD, professor of dermatology and of epidemiology and director of the Psoriasis and Phototherapy Treatment Center at the University of Pennsylvania Perelman School of Medicine, tells Verywell that this could explain some of the differences in risk that were seen.

The Risks and Benefits of Biologics

Biologic drugs are very large, complex molecules or mixtures of molecules that are used to treat autoimmune diseases like psoriasis, rheumatoid arthritis, and other conditions. They are often produced using recombinant DNA technology and are usually very expensive.

Biologics can be hormones, cytokines, growth factors, vaccines, interferon, or monoclonal antibody (mAb) products. In treating psoriasis, biologics include tumor necrosis factor inhibitors and interleukin inhibitors.

Biologics work by suppressing the immune system and, as a result, make the body vulnerable to infections.

“One of the fundamental principles of the field I practice in, pharmaco-epidemiology, is that when it comes to selecting a medicine it's not just about risks or benefits, it's about risks and benefits. And about that balance,” Alexander tells Verywell.

“All medicines have risks. and most medicines have rare but serious risks. Biologic drugs are no different,” Alexander says. “It's vital that clinicians and patients are aware of these risks and understand them and include them in their appraisals of whether it's right to move up to one of these drugs."

While the drugs can be a game-changer autoimmune disease treatment, patients taking biologics need to regularly discuss the risks and benefits with their doctors.

“It's vital that clinicians and patients are aware of these risks and understand them and include them in their appraisals of whether it's right to move up to one of these drugs,” Alexander says. “At times, the risks of therapies can be overlooked at the expense of an almost exclusive focus on the potential benefits of treatment. I think we often fail to carefully consider and balance the risks with the benefits.”

According to Alexander, most of the serious infections that are linked to biologics and other drugs that suppress the immune system occur during the first several months of use. However, that does not mean that there is no risk after that—Alexander says that "the risk of serious infections is real, and it's ever-present.”

Gelfand adds that “as we have more biologic treatments to select from, patients and clinicians need better data to determine which options are best."

What This Means For You

Biologic drugs can provide many patients with relief from psoriasis, psoriatic arthritis, and other autoimmune diseases. However, these drugs do come with risks—especially related to a suppressed immune system. The risk of infections is always something that should be discussed by patients taking these medications and their doctors, but they are particularly important to consider amid the COVID pandemic.

Using Biologics During COVID-19

During the COVID-19 pandemic, many people taking immunosuppressant drugs have been concerned about what the treatment means for their chances of getting COVID, as well as how it might affect the effectiveness of the COVID vaccines.

Gelfand co-chairs The National Psoriasis Foundation COVID-19 task force and says that the organization "recommends that patients who are not infected with SARS-CoV-2 continue their biologic or oral therapies for psoriasis and/or psoriatic arthritis in most cases."

“The current data suggests that psoriasis treatments do not meaningfully increase the risk of developing severe COVID-19 illness,” Gelfand adds, echoing the findings of a study published by Alexander and colleagues in January.

Bottom line: Decisions on whether to start or continue with biologics for psoriasis and psoriatic arthritis during the pandemic should be between patients and their doctors.

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