Infliximab
Chimeric (human constant part, murine variable part) monoclonal
antibody against TNFα.
Indications
Crohn's disease resistant to conventional treatment or with fistulae.
Rheumatoid arthritis unresponsive to methotrexate.
Has been tried in UC, but results not so impressive.
Method of administration
Slow intravenous infusion.
Single dose (severe Crohn's disease); three doses (Crohn's with fistulae);
Every 8/52 + methotrexate (rheumatoid arthritis).
Adverse effects
Usually none. Hypersensitivity reactions (urticaria, dyspnoea, hypotension),
serum sickness, prone to infection; lupus-like syndrome.
Benefits
Crohn's: reduces need for surgery by 15%. Clinical improvement seen in
up to 80% of patients.
Cost
£400 per 100 mg vial. 3 mg/kg for RhA is £800, 5 mg/kg for Crohn's is £1200 for
a 70 kg man.
Evidence
ATTRACT trial: double blind placebo controlled trial. Infliximab in
patients with RhA despite methotrexate. Halts radiographic progression,
response maintained at 2 y.