TREMFYA (guselkumab) is an IL-23 p19 antagonist for plaque psoriasis, PsA, UC, and CD. Typical dosing is 100 mg SC q8 weeks (after induction) or IV/SC induction for IBD. Monitor for infection and hepatotoxicity, screen for TB, avoid live vaccines, and educate patients on self-injection and storage.
Tuberculosis: evaluate for latent or active TB; treat latent TB prior to use; monitor throughout.
Liver Function: obtain ALT/AST and bilirubin prior to UC/CD therapy; for psoriasis/PsA if clinically indicated.
Vaccinations: complete all age-appropriate immunizations; avoid live vaccines during treatment.
Infection status: defer therapy if clinically important active infection is present.
Dosage Adjustment
Renal / Hepatic impairment: no formal adjustment data; monoclonal antibody clearance via catabolism—dose change not recommended, but monitor hepatic function closely.
Elderly: pharmacokinetics similar to younger adults—no adjustment required.
Body Weight: exposure increases with weight, but clinical data support fixed dose.
Intravenous Formulation Preparation
Vial: 200 mg / 20 mL (10 mg/mL)
Dilution (for UC/CD induction)
Remove 20 mL of 0.9% NaCl from a 250 mL bag.
Add 20 mL (200 mg) TREMFYA to bag → final conc ≈ 0.8 mg/mL.
Gently mix (do not shake); inspect for particulate matter / discoloration.
Infuse over ≥ 1 hour using sterile, low-protein-binding 0.2 µm filter.
Do not co-infuse with other IV products.
Use within 10 hours at ≤ 25 °C (77 °F); do not freeze; discard unused solution.
Hazardous / Reproductive Hazards
Hazardous Classification: monoclonal antibody — not listed as NTP/IARC carcinogen or NIOSH hazardous drug; use standard mAb handling precautions.
Pregnancy: human data insufficient; animal studies show no major malformations but neonatal deaths at high exposures; registry available ( MotherToBaby.org ).
Lactation: unknown if excreted in human milk; not detected in monkey milk.
Contraception: no specific requirement but discuss risks vs benefits in pregnancy.
Live Vaccines: contraindicated during treatment.
Clinical Pearls
Dual Induction Options: IV or SC induction for UC/CD offers flexibility between infusion center and home use transition.
Hepatotoxicity Monitoring: new PI (2025) emphasizes drug-induced liver injury reports — monitor LFTs for ≥16 weeks after start and periodically thereafter.
TB screening is mandatory, even in IBD where TNF failures may coexist.
Avoid live vaccines but inactive vaccines (e.g., influenza, COVID-19 mRNA) may be given.
Self-Injection Devices: One-Press injector and pen available; train patients to avoid psoriatic lesions or tender skin areas.
Storage: Refrigerate (2–8 °C), protect from light, allow 30 min to reach room temp before use.
Discontinue if serious infection or anaphylaxis occurs.
