Which agent is an IL-23 inhibitor used in psoriatic arthritis?

Which agent is an IL-23 inhibitor used in psoriatic arthritis?

• A. Secukinumab
• B. Ixekizumab
• C. Guselkumab
• D. Ustekinumab

Answer: (C)

Blocking IL-23 with a p19-targeted antibody reduces the Th17-driven inflammation that underlies psoriatic arthritis. Guselkumab binds the p19 subunit of IL-23, preventing its signaling and lowering IL-17–mediated inflammation, which helps improve psoriatic arthritis symptoms. The other options target different parts of the inflammatory pathway: IL-17A inhibitors (secukinumab and ixekizumab) block the downstream effects of IL-17A itself, while ustekinumab blocks IL-12 and IL-23 by targeting the p40 subunit, making it not a pure IL-23 inhibitor. Thus, guselkumab is the IL-23 inhibitor used in psoriatic arthritis.

Blocking IL-23 with a p19-targeted antibody reduces the Th17-driven inflammation that underlies psoriatic arthritis. Guselkumab binds the p19 subunit of IL-23, preventing its signaling and lowering IL-17–mediated inflammation, which helps improve psoriatic arthritis symptoms. The other options target different parts of the inflammatory pathway: IL-17A inhibitors (secukinumab and ixekizumab) block the downstream effects of IL-17A itself, while ustekinumab blocks IL-12 and IL-23 by targeting the p40 subunit, making it not a pure IL-23 inhibitor. Thus, guselkumab is the IL-23 inhibitor used in psoriatic arthritis.