IL-23 Inhibitor — Psoriasis Pregnancy: Avoid — limited data; IgG crosses placenta; use effective contraception during and for 12 weeks after last dose

Guselkumab

Brand names: Tremfya

Adult dose

Dose: 100 mg SC at weeks 0 and 4, then every 8 weeks

Route: SC injection

Frequency: Every 8 weeks (maintenance — after two loading doses)

Max: 100 mg every 8 weeks

Selective IL-23p19 inhibitor for moderate-to-severe plaque psoriasis and psoriatic arthritis. More selective than ustekinumab (IL-12/23) — targets only IL-23 pathway. 8-weekly maintenance dosing is convenient. Onset slower than IL-17 inhibitors but durable remission.

Paediatric dose

Dose: Seek specialist opinion mg/kg

Route: SC

Frequency: Every 8 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

VOYAGE-1 and VOYAGE-2 trials: guselkumab achieved PASI 90 in ~70–73% and PASI 100 in ~37% at week 16 — superior to adalimumab
HEAD-TO-HEAD trial (ECLIPSE): guselkumab non-inferior to secukinumab at 12 weeks but superior at week 48 — durable response advantage
Selectively inhibits IL-23 (p19 subunit) without affecting IL-12 — may preserve Th1 immunity better than ustekinumab
No IBD risk signal (unlike IL-17 inhibitors) — preferred choice in psoriasis patients with concurrent Crohn's disease
8-weekly maintenance is more convenient than 4-weekly (secukinumab, ixekizumab) — improves long-term adherence
NICE TA574: guselkumab recommended for severe plaque psoriasis after failure of conventional systemic therapy

Contraindications

Active infection (including active TB)
Hypersensitivity to guselkumab

Side effects

Nasopharyngitis
Upper respiratory tract infection
Injection site reactions
Headache
Arthralgia
Diarrhoea

Interactions

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

Monitoring

PASI/IGA at 16 weeks (NICE: ≥75% PASI reduction)
Infection surveillance
TB screening before initiating

Reference: BNFc; BNF 90; VOYAGE-2 Trial (Reich et al. JAAD 2017); ECLIPSE Trial (Langley et al. NEJM 2021); NICE TA574; SPC Tremfya. Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways