Psoriasis — SCE Dermatology MCQ
Instant feedback + full explanation. One question, done properly.
Educational content. Not a substitute for clinical judgement or local policy.
Reveal the answer and explanation
Correct answer: C — Risankizumab selectively targets the p19 subunit of IL-23 only; Ustekinumab targets the shared p40 subunit blocking both IL-12 and IL-23
Risankizumab is a selective IL-23 inhibitor targeting the p19 subunit (shared only by IL-23, not IL-12). Ustekinumab targets the p40 subunit shared by both IL-12 and IL-23. By selectively blocking IL-23 (p19), Risankizumab inhibits the Th17 axis (the dominant pathway in psoriasis) while preserving IL-12-mediated Th1 immunity (important for anti-tumour and anti-infective responses). This selective approach may theoretically improve the safety profile. Risankizumab has demonstrated very high PASI 90/100 rates and sustained long-term efficacy with infrequent dosing (150 mg SC every 12 weeks after loading). Other selective IL-23 inhibitors include Guselkumab and Tildrakizumab.
Reference: NICE TA596 2019 Risankizumab; BAD 2020