IL-23 Inhibitor — Psoriasis / Crohn's Pregnancy: There are no or limited data (fewer than 300 pregnancy outcomes) from use in pregnant women; animal studies do not indicate direct or indirect harmful effects with respect to reproductive toxicity. As a precautionary measure, it is preferable to avoid the use of risankizumab during pregnancy. Women of childbearing potential should use an effective method of contraception during treatment and for at least 21 weeks after treatment. Breast-feeding: it is unknown whether risankizumab is excreted in human milk; a risk to the breast-fed infant cannot be excluded in the first few days after birth.

Risankizumab

Brand names: Skyrizi

Risankizumab is a monoclonal antibody biologic given by subcutaneous injection for moderate-to-severe plaque psoriasis and for psoriatic arthritis.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: 150 mg — given either as two 75 mg pre-filled syringe injections or as one 150 mg pre-filled pen or pre-filled syringe injection

Route: Subcutaneous injection into the thigh or abdomen (administration in the upper, outer arm may only be performed by a healthcare professional or caregiver)

Frequency: Week 0, week 4, then every 12 weeks thereafter

Intended for use under the guidance and supervision of a physician experienced in the diagnosis and treatment of the conditions for which risankizumab is indicated. Consideration should be given to discontinuing treatment in patients who have shown no response after 16 weeks of treatment; some plaque psoriasis patients with an initial partial response may subsequently improve with continued treatment beyond 16 weeks. Missed dose: administer as soon as possible, then resume the regular schedule. Patients should not inject into areas where the skin is tender, bruised, erythematous, indurated or affected by psoriasis. Patients may self-inject after training in subcutaneous injection technique. Elderly (65 years and over): no dose adjustment required (limited information in subjects aged 65 and over). Overweight patients: no dose adjustment required. Paediatric (UK SPC): safety and efficacy in children and adolescents aged 5 to less than 18 years have NOT been established (no data available); there is no relevant use below 6 years for moderate to severe plaque psoriasis or below 5 years for psoriatic arthritis. NOTE — US labelling (Skyrizi, AbbVie) differs and does give weight-band paediatric dosing for patients 6 years of age and older with plaque psoriasis or psoriatic arthritis: less than 40 kg, 55 mg; 40 kg or greater, 150 mg, each at Week 0, Week 4 and every 12 weeks thereafter. This is a weight band, not a per-kg dose, and is not part of the UK SPC — verify paediatric use against a children's formulary. The US label also carries dosing for Crohn's disease and ulcerative colitis (intravenous induction then subcutaneous maintenance) which is outside this dermatology page's scope.

Dose adjustments

Renal

No specific studies were conducted to assess the effect of renal or hepatic impairment on the pharmacokinetics of risankizumab; these conditions are generally not expected to have any significant impact on the pharmacokinetics of monoclonal antibodies and no dose adjustments are considered necessary.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Hypersensitivity to the active substance or to any of the excipients
Clinically important active infections (e.g. active tuberculosis)

Side effects

Upper respiratory infections (very common)
Tinea infections (common)
Headache (common)
Pruritus, rash and eczema (common)
Fatigue and injection site reactions (common)
Rare: anaphylactic reactions

Interactions

Risankizumab is not expected to undergo metabolism by hepatic enzymes or renal elimination; interactions with inhibitors, inducers or substrates of medicinal product metabolising enzymes are not expected and no dose adjustment is needed
The safety and efficacy of risankizumab in combination with immunosuppressants, including biologics, or with phototherapy have not been evaluated
Live vaccines: wait at least 4 weeks after live vaccination before starting treatment; patients should not receive live vaccines during treatment and for at least 21 weeks after treatment

Clinical monograph

How it works

It selectively binds the p19 subunit of interleukin-23, inhibiting this cytokine and the downstream Th17 inflammatory pathway central to psoriatic plaque formation.

Prescribing in practice

Screen for latent tuberculosis and active infection before starting, and treat latent TB as appropriate before initiation.
Avoid live vaccines during treatment and ensure immunisations are up to date beforehand.
Given by subcutaneous injection with maintenance dosing every few months after loading doses.

Monitoring

Monitoring is clinical, assessing skin and joint response and reviewing for signs of infection during treatment.

Counselling the patient

After the initial doses, maintenance injections are needed only every few months.
Report symptoms of infection such as fever or persistent cough.
Tell healthcare staff you are on a biologic before having any vaccinations.

Evidence & guidelines

Risankizumab's efficacy in plaque psoriasis was shown in the UltIMMa phase 3 trials, and it is recommended by NICE within its licensed indications.

Reference: IMMvent Trial (Reich et al. Lancet 2019); NICE TA596; SPC Skyrizi; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways