Infliximab is a monoclonal antibody that is administered intravenously to treat a number of chronic inflammatory conditions. Also known by the brand name Remicade, infliximab first received approval from the Food and Drug Administration in August 1998 for the treatment of Crohn’s disease.

In 2004, this approval was extended to rheumatoid arthritis and in 2005 to ulcerative colitis. The treatment also received approval for the treatment of pediatric Crohn’s in 2006 and pediatric ulcerative colitis in 2011.

Infliximab works by blocking the functional activity of a cell signalling protein (cytokine) called tumor necrosis factor alpha (TNF-α), a substance that plays a key role in inflammation. Using infliximab to inhibit TNF-α does not cure inflammatory disease, but it reduces the signs and symptoms of inflammation that arise in patients with such conditions.

In the UK, infliximab is approved for treatment of the following patients:

• Those with severe and active Crohn’s disease that has failed to respond to a full course of treatment with a corticosteroid and/or immunosuppressant and those who are intolerant to these therapies or have medical contraindications for them.

For these patients, infliximab is administered by intravenous infusion at a dosage of 5 mg per kg of body weight (5mg/kg) over a period of two hours. This is followed by a repeat infusion two weeks later. If symptoms do not improve after these two doses, no further treatment is administered and in cases where disease does respond, patients receive maintenance treatments of 5 mg/kg infusions 6 weeks after the first dose, with infusions then following every 8 weeks. For adults, dose escalation may be an option if disease stops responding.

• Those with active, fistulising Crohn’s disease that has failed to respond to a full course of conventional therapies such as drainage, antibiotics and an immunosuppressant.

For these patients, infliximab is infused at a dose of 5 mg/kg for 2 hours with repeat infusions two and six weeks later. In cases where disease fails to respond after these three doses, no further infliximab infusions are given. For those with disease that does respond, maintenance infusions of 5 mg/kg may be given every eight weeks or a re-administration treatment of 5 mg/kg may be given when symptoms recur, followed by the same infusion every 8 weeks. For adults, dose escalation may be considered if their disease has stopped responding.

• Those aged 6 to 17 years with severe and active Crohn’s disease that has failed to respond to conventional therapies including primary nutrition therapy, an immunomodulatory drug and a corticosteroid or who are intolerant or have medical contraindications for these therapies.

For these patients, intravenous infusions of 5 mg/kg are given followed by repeat infusions two and six weeks later, and then every 8 weeks.

The cost of a 100mg vial of infliximab is £419.62 excluding VAT. Since the dose is adjusted according to a person’s body weight, the cost of treatment varies between individuals. The cost for someone weighing 73 kg, for example, would be £1,678 because four 100 mg vials would be needed to administer a dose of 365 mg. With an assumed administration cost per infusion of £258, the cost of two infusions would be around £3,872. To continue therapy at the standard dose over a total of twelve months, the cost would be around £12,584.