New biologic therapeutics for ulcerative colitis and Crohn's disease.

INTRODUCTION: Some inflammatory bowel disease (IBD) patients especially those with refractory Crohn's disease (CD) or relapsing ulcerative colitis (UC) do not respond to current therapies. The newly introduced biological drugs have got some interest due to their specificity and selectivity in modulation of inflammatory elements. AREAS COVERED: In 46 included randomized, placebo-controlled clinical trials, the efficacy and safety of different biologic drugs have been evaluated in moderately to severely active CD or UC patients. Current investigated drugs include new anti-TNF drugs (adalimumab, certolizumab pegol, etanercept, onercept and golimumab), anti-CD20 (rituximab), T-cell inhibitors (abatacept) and anti-α4 integrins (natalizumab and vedolizumab). Adalimumab, certolizumab, and golimumab showed significant efficacy in induction of remission and maintenance in CD and UC patients with a rate of adverse events similar to placebo in the major trials. Natalizumab and vedolizumab were effective in the treatment of moderately to severely active CD and UC patients. However, vedolizumab caused less adverse effects than natalizumab. onercept, etanercept, rituximab and abatacept were all well tolerated but were not effective in CD or UC patients. EXPERT OPINION: Anti-TNF drugs, except for onercept and etanercept, and anti-α4 integrins exhibit beneficial therapeutic effects. Although they were all well tolerated, the incidence of progressive multifocal leukoencephalopathy associated with natalizumab should not be missed.