Infliximab for the treatment of Crohn's disease: Review and indications for clinical use in Canada

Crohn's disease is a chronic inflammatory disorder of the gastrointestinal tract. It may affect any portion of the gastrointestinal tract from the mou th to the anus. Symptoms typically include cramping abdominal pain, diarrhe a (which may be bloody) and nausea. As the severity of the illness worsens, patients may experience constant abdominal pain, vomiting, weight loss and fever. From the perspective of the patient, disease symptoms significantly impair quality of life, and interfere with their work environment and acti vities of daily living. Unfortunately, there is no cure for Crohn's disease . Patients experience a chronic, relapsing course characterized by recurren t flares of their disease. Conventional medical treatment of Crohn's diseas e includes the use of nonspecific anti inflammatory drugs (5-aminosalicylic acid agents, prednisone, budesonide), immunosuppressives (6-mercaptopurine , azathioprine, methotrexate) and antibiotics. A variable onset of action, incomplete response rates and a significant risk of adverse effects charact erize current therapies. Although surgery is frequently used to treat compl ications or medically refractory disease, postoperative recurrence is a com mon problem. Infliximab, a murine chimeric monoclonal antibody directed tow ard tumour necrosis factor-alpha, is a highly effective treatment of active Crohn's disease. In randomized, placebo-controlled clinical trials, 33% of patients treated with infliximab 5 mg/kg achieved remission (Crohn's Disea se Activity Index score less than 150), compared with only 4% of those rece iving placebo (P <0.001). Additionally, infliximab is the only drug therapy shown to be effective for the treatment of fistulizing Crohn's disease. In studies done to date, infliximab appears to be well tolerated and has a fa vourable side effect profile.