IL-23 Inhibitor — Psoriasis / Crohn's Pregnancy: Avoid — limited data; IgG crosses placenta; effective contraception required during and for 21 weeks after last dose

Risankizumab

Brand names: Skyrizi

Adult dose

Dose: 150 mg SC (two 75 mg injections) at weeks 0, 4, then every 12 weeks

Route: SC injection

Frequency: Every 12 weeks (maintenance — after two loading doses)

Max: 150 mg every 12 weeks

Selective IL-23p19 inhibitor for moderate-to-severe plaque psoriasis, psoriatic arthritis, and Crohn's disease. 12-weekly maintenance is the most convenient dosing schedule among IL-23 inhibitors. High rates of complete skin clearance (PASI 100).

Paediatric dose

Dose: Seek specialist opinion mg/kg

Route: SC

Frequency: Every 12 weeks

Max: Not established in children

Not licensed in children — specialist paediatric dermatology use only

Dose adjustments

Renal

No dose adjustment required

Hepatic

No dose adjustment required

Paediatric weight-based calculator

Patient weight (kg)

Not licensed in children — specialist paediatric dermatology use only

Clinical pearls

IMMhance, IMMvent, IMMtrue trials: risankizumab achieved PASI 90 in ~75% and PASI 100 in ~36–56% at week 16 — among highest complete clearance rates of any biologic
IMMvent trial (head-to-head vs adalimumab): risankizumab superior in PASI 90 achievement at weeks 16 and 44
12-weekly maintenance is the most convenient schedule — only biologic requiring injections every 3 months; significant adherence advantage
Also approved for Crohn's disease (IV induction then SC maintenance) — unlike IL-17 inhibitors, no IBD risk
NICE TA596: risankizumab recommended for moderate-to-severe plaque psoriasis after failure of conventional systemic therapy
No signal for worsening IBD — may be preferred biologic for psoriasis patients with co-existing inflammatory bowel disease

Contraindications

Active infection (including active TB)
Hypersensitivity to risankizumab

Side effects

Nasopharyngitis
Upper respiratory tract infections
Injection site reactions
Headache
Fatigue
Tinea infections (rare — less than IL-17 inhibitors)

Interactions

Live vaccines — avoid during treatment
CYP450 normalisation — monitor narrow TI drugs

Monitoring

PASI/IGA at 16 weeks
Infection surveillance
TB and hepatitis B screening before initiating

Reference: BNFc; BNF 90; IMMvent Trial (Reich et al. Lancet 2019); NICE TA596; SPC Skyrizi. Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways