Risankizumab

1. Indications

Guselkumab is an interleukin-23 (IL-23) antagonist indicated for the treatment of several immune-mediated diseases in adult patients. These include moderate-to-severe plaque psoriasis suitable for systemic therapy or phototherapy, active psoriatic arthritis, moderate-to-severe active Crohn's disease, and moderate-to-severe active ulcerative colitis.

2. Recommended Dosage and Administration

The dosing schedule varies by indication.

For plaque psoriasis and psoriatic arthritis, the recommended dose is 150 mg administered via subcutaneous injection at weeks 0 and 4, followed by maintenance every 12 weeks. In psoriatic arthritis, it may be used as monotherapy or in combination with non-biologic DMARDs.

For Crohn's disease, liver enzyme and bilirubin levels must be checked prior to initiation. The induction dose is 600 mg via intravenous infusion (over at least 1 hour) at weeks 0, 4, and 8. The maintenance dose is 180 mg or 360 mg subcutaneously every 8 weeks starting at week 12. Clinicians should use the lowest effective dose for maintenance.

For moderate-to-severe active ulcerative colitis, the induction dose is 1200 mg via intravenous infusion (over at least 1 hour) at weeks 0, 4, and 8. The maintenance dose is 180 mg or 360 mg subcutaneously every 8 weeks starting at week 12, using the lowest effective dose.

3. Safety and Adverse Reactions

Common adverse reactions vary by disease phase:

In plaque psoriasis and psoriatic arthritis (≥1%), the most frequent are upper respiratory infection, headache, fatigue, injection site reactions, and tinea infections.

In Crohn's disease (>3%): During induction, upper respiratory infection, headache, and arthralgia are common. During maintenance, arthralgia, abdominal pain, injection site reactions, anemia, pyrexia, back pain, arthropathy, and urinary tract infections are reported.

In ulcerative colitis (≥3%): Induction phase commonly sees arthralgia. Maintenance phase commonly sees arthralgia, pyrexia, injection site reactions, and rash.

4. Pharmacological Action

Guselkumab is a humanized IgG1 monoclonal antibody that selectively binds to the p19 subunit of human IL-23 cytokine, inhibiting its interaction with the IL-23 receptor. IL-23 is a naturally occurring cytokine involved in inflammatory and immune responses. By blocking this pathway, the drug inhibits the release of pro-inflammatory cytokines and chemokines.

5. Storage Conditions

Store refrigerated between 2°C and 8°C. Do not freeze or shake. Keep in the original package to protect from light. The packaging is not made with natural rubber latex.