What is infliximab (Remicade)?

What is Infliximab (Remicade)?

Infliximab is a chimeric IgG1κ monoclonal antibody that specifically targets and neutralizes tumor necrosis factor-alpha (TNF-α), a key pro-inflammatory cytokine involved in various inflammatory conditions. 1

Mechanism of Action

Infliximab works by:

• Binding with high affinity to both soluble and transmembrane forms of TNF-α
• Inhibiting TNF-α from binding to its receptors
• Neutralizing the biological activity of TNF-α
• Potentially causing lysis of cells expressing transmembrane TNF-α 1

These actions lead to:

• Reduction of pro-inflammatory cytokines (IL-1, IL-6)
• Decreased leukocyte migration
• Reduced expression of adhesion molecules
• Inhibition of tissue-degrading enzymes produced by synoviocytes and chondrocytes 1

Approved Indications

Infliximab is FDA-approved for multiple inflammatory conditions:

• Rheumatologic conditions:

  • Rheumatoid arthritis (with methotrexate)
  • Ankylosing spondylitis
  • Psoriatic arthritis 2

• Dermatologic conditions:

  • Moderate-to-severe plaque psoriasis 2

• Gastrointestinal conditions:

  • Moderately to severely active Crohn's disease
  • Fistulizing Crohn's disease
  • Ulcerative colitis 2, 3, 4

Dosing and Administration

Infliximab is administered intravenously with the following standard dosing regimen:

• Initial induction: 5 mg/kg at weeks 0,2, and 6
• Maintenance: 5 mg/kg every 8 weeks thereafter 2

In certain clinical scenarios:

• Doses may be increased up to 10 mg/kg
• Frequency may be increased to every 4-6 weeks in patients with inadequate response 2, 5

Efficacy

Infliximab has demonstrated significant efficacy across multiple conditions:

• Crohn's disease: Strongly recommended for induction and maintenance of fistula remission (strong recommendation, moderate certainty of evidence) 2

• Psoriasis: Recommended as monotherapy for moderate-to-severe plaque psoriasis with high efficacy rates (Strength of recommendation A) 2

• Psoriatic arthritis: Effective for both joint disease and skin manifestations 5

Important Considerations

Concomitant Medications

• Combining infliximab with methotrexate reduces immunogenicity and improves long-term efficacy 2, 5
• Using infliximab with antibiotics is recommended for induction of fistula remission in Crohn's disease 2

Safety Monitoring

• Pre-treatment screening:

  • Hepatitis serology (avoid if active viral hepatitis is present)
  • Tuberculosis screening 2

• Ongoing monitoring:

  • Watch for infections (most common adverse events)
  • Monitor for infusion reactions (can occur in up to 20% of patients)
  • Increased risk of opportunistic infections, particularly tuberculosis 2, 6
  • Higher risk of serious infections in elderly patients 1

Contraindications and Precautions

• Live vaccines should be avoided during treatment 2
• Use with caution in patients with history of malignancy
• Monitor for potential hepatotoxicity 6

Clinical Pearls

• Infliximab has a molecular weight of approximately 149.1 kilodaltons 1
• It's supplied as a sterile, white, lyophilized powder for intravenous infusion 1
• The addition of methotrexate should be strongly considered for all patients to reduce antibody formation against infliximab 2
• Patients should be monitored for fever and signs of infection during treatment 2