As part of MDLinx’s Smartest Doc Rheumatology Challenge, we asked doctors, “What is the most common misconception about biologic therapies for psoriatic arthritis (PsA)?” Only 50% selected the correct answer: Biologics cause frequent serious infections. 

PsA patients and infection risk: Real-world results

There are many FDA-approved targeted biologic therapies for PsA on the market, including tumor necrosis factor-alpha (TNF) inhibitors, interleukin 12 and 23 (IL-12/23) inhibitors, IL-17 inhibitors, IL-23 inhibitors, IL-36 pathway inhibitors, and T-cell inhibitors.

Current Biologics on the Market for Psoriatic Disease. National Psoriasis Foundation. 2025.

For context, one 2018 study of 5,596 patients diagnosed with rheumatoid arthritis, axial spondyloarthritis, or PsA, infection-related hospitalizations occurred in 289 of the study participants—65 were PsA patients.

Quartuccio L, Zabotti A, Del Zotto S, et al. Risk of serious infection among patients receiving biologics for chronic inflammatory diseases: Usefulness of administrative data. Journal of Advanced Research. 2018;15:87–93.

The majority of these patients were taking TNF inhibitors, such as adalimumab and etanercept. Of the 65 patients, the majority (23) had respiratory (non-tuberculosis) and gastrointestinal infections. Event-free survival was nearly 90% among patients using biologics after 12 years of follow-up. 

Now, let’s look at another group of popular biologic agents: IL-23s, such as risankizumab. A 2022 study found that the most common adverse events with risankizumab included viral upper respiratory tract infection and headache.

Mease PJ, Kellner H, Morita A, et al. Long-Term Efficacy and Safety of Risankizumab in Patients with Active Psoriatic Arthritis: Results from a 72-Week Phase 2 Randomized Trial. Rheumatology and Therapy. 2022;9(5):1361–1375.

Out of 180 patients, only 2 experienced serious infections.

What the experts say

Other research supports the use of IL-17 inhibitors, In terms of both efficacy and safety, may be the most favourable option for PsA patients who are new to biologics.

Lin J, Ren Y. Different biologics for biological-naïve patients with psoriatic arthritis: a systematic review and network meta-analysis. Frontiers in Pharmacology. 2024;15:1279525.

Overall, the news looks good for PsA patients: A large and exhaustive French study from 2024—including more than 12,000 PsA patients treated with biologics—found only a 3% serious infection rate.

Cooper J. Targeted psoriatic arthritis therapies demonstrate low risk for serious infection. Healio. June 6, 2024.

According to Julius Birnbaum, MD, MHS, Associate Professor of Rheumatology at the University of Pittsburgh Medical Center and author of Living Well with Autoimmune Diseases, “[Biologics] overall have a high risk-to-benefit ratio, especially when the risk of certain opportunistic infections is mitigated by vaccinations.” 

Certain patients, however, may be more predisposed to infection than others, which means not every patient is at high risk. “There are patients who might be more predisposed to having a higher risk of opportunistic infections,” Dr. Birnbaum says. “Such patients might be frail, elderly, have poor nutrition, have more active autoimmune diseases, or have multiple wounds.”