When and why rheumatologists consider IL-23s for psoriatic arthritis treatment

By Lisa Marie Basile | Fact-checked by Davi Sherman

Published February 28, 2025

Key Takeaways

Industry Buzz

“IL-23 inhibitors offer high efficacy on skin and joint manifestations, good safety, and convenient dosing (four to six injections per year).” — Anca D. Askanase, MD, MPH
“Consider an IL-23 when a patient's quality of life or function is severely affected and involves joints, but not the spine, or [when] there is an inadequate response to conventional DMARDs like methotrexate or to biologics such as TNF inhibitors.” — Stella Bard, MD

Find more of your peers' perspectives and insights below.

Several biologics on the market are used to treat PsA. Over the last few years, physicians have turned to interleukin (IL)-23 inhibitors. IL-23 is a sort of “master switch,” which can reprogram immune cells by inducing and maintaining a highly pro-inflammatory state.^[] It’s associated with several immune-mediated inflammatory diseases, like psoriasis, PsA, and inflammatory bowel disease.

So, when and why should you treat with IL-23 vs another drug? Considerations for physicians include symptomology, severity, previous treatment failures, and use of administration.

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When rheums consider IL-23s

“There are no head-to-head studies comparing IL-23 inhibitors to IL-17 or TNF inhibitors,” says Anca D. Askanase, MD, MPH, Professor of Medicine in the Division of Rheumatology and Clinical Immunology at Columbia University Vagelos College of Physicians and Surgeons. That said, “IL-23 inhibitors offer high efficacy on skin and joint manifestations, good safety, and convenient dosing (four to six injections per year),” she says.

Dr. Askanase says she usually prescribes an IL-23 after patients fail conventional disease-modifying antirheumatic drugs (DMARDs) or if they’ve tried and failed an IL-17 or TNF inhibitor.

"Extensive skin disease and the use of administration are the best arguments for the early introduction of IL-23 inhibitors."

— Anca D. Askanase, MD, MPH

Stella Bard, MD, a board-certified rheumatologist who manages complex rheumatologic conditions, agrees, saying that she usually prescribes IL-23 “when a patient's quality of life or function is severely affected and involves joints, but not the spine.” She also administers an IL-23 “when a patient prefers injections—vs tablets—that only need to be administered quarterly,” as is the case with risankizumab (Skyrizi).

Dr. Bard also considers co-occurring disease when prescribing this class of drugs: “IL-23 is a safer option for concomitant inflammatory bowel disease [and] predominant skin involvement, and [it] treats both skin and joint symptoms. They are better-tolerated due to a better safety profile,” she says.

Clinical implications

IL-23 inhibitors are newer, but they have garnered interest for their efficacy and safety profile. A review published in Immunology Research looked at several biologics and found that IL-23s showed a “significantly higher” American College of Rheumatology 20 (ACR20) response rate than placebo at week 24, without an increase in adverse events.^[]

Immunology Research also reported that IL-23s may have better efficacy than TNF inhibitors when it comes to enthesitis remission rate. The researchers also noted that the IL-23 inhibitor guselkumab was more effective than TNF inhibitors in treating psoriatic skin. “IL-23 inhibitors effectively improved joint disease activity in PsA patients while also having a good safety profile,” the authors concluded.

According to Expert Opinion on Biological Therapy, IL-23s are ineffective in treating spondyloarthritis, such as ankylosing spondylitis, which primarily affects the spine.^[]