Efficacy and safety of adalimumab in Crohn's disease.

Adalimumab (ADA) is a subcutaneously (SC) self-administered fully human Ig G1 monoclonal antibody directed against tumor necrosis factor alpha (TNFce). In the CLASSIC dose-ranging trial, ADA was superior to placebo for inducing remission in patients with moderate-to-severe Crohn's disease (CD) naive to TNFa inhibitor therapy. In CLASSIC II, patients in remission following CLASSIC I maintained remission for up to 56 weeks while on ADA. In CHARM, approximately 40% of the 499 patients with moderate-to-severe CD who responded to ADA, maintained remission at 26 and 52 weeks, thus confirming long-term efficacy. ADA demonstrated steroid-sparing properties, beneficial effects in patients with perianal fistulas, and decreases in rates of hospitalization and surgery. Sub-group analyses demonstrated similar remission rates irrespective of concomitant immunosuppressive use or previous exposure to other TNFa inhibitor therapy. In the GAIN trial, 325 patients who had either lost response or become intolerant to infliximab (IFX) were randomized to recieve ADA induction therapy or placebo. In this difficult-to-treat patient population, 21% achieved remission and half demonstrated clinical benefit from ADA induction therapy. Injection site reactions may occur with SC ADA (2-5% of patients), which are generally less dramatic in nature than infusion reactions experienced with intravenous IFX. Immunogenicity occurs with all monoclonal antibodies; however, in the CD development program anti-ADA antibodies were detected at low rates (0.7 and 2.6% of patients in the CLASSIC I and CLASSIC II studies, respectively). Based on robust short- and long-term efficacy data from large randomized controlled trials and a favorable safety signal, ADA has become a key addition to the therapeutic armamentarium in the treatment of moderate-to-severe CD.