Which is NOT listed as an IL-23 inhibitor in the source?

Which is NOT listed as an IL-23 inhibitor in the source?

• A. Guselkumab
• B. Tidrakizumab
• C. Risankixumab
• D. Ustekinumab

Answer: (D)

IL-23 inhibitors block the p19 subunit specific to IL-23, cutting IL-23 signaling while largely preserving IL-12. Drugs like guselkumab, tildrakizumab, and risankizumab all target that p19 subunit, so they are IL-23–specific inhibitors. Ustekinumab, however, binds the p40 subunit shared by both IL-12 and IL-23, reducing activity of both cytokines rather than IL-23 alone. Because the question asks for the one not listed as an IL-23 inhibitor, the correct choice is ustekinumab.

IL-23 inhibitors block the p19 subunit specific to IL-23, cutting IL-23 signaling while largely preserving IL-12. Drugs like guselkumab, tildrakizumab, and risankizumab all target that p19 subunit, so they are IL-23–specific inhibitors. Ustekinumab, however, binds the p40 subunit shared by both IL-12 and IL-23, reducing activity of both cytokines rather than IL-23 alone. Because the question asks for the one not listed as an IL-23 inhibitor, the correct choice is ustekinumab.