Lack of effectiveness of the platelet-activating factor antagonist SR27417A in patients with active ulcerative colitis: a randomized controlled trial. The Platelet Activating Factor Antagonist Study Group in Ulcerative Colitis.

Platelet-activating factor (PAF) is increased during relapse of ulcerative colitis. In animal models of experimental colitis, specific inhibition of PAF has reduced inflammation. The aim of this study was to evaluate the efficacy and safety of the PAF antagonist SR27417A in moderately active UC. A double-blind multicenter trial was conducted during a 28-day period in hospital outpatients with an exacerbation of ulcerative colitis. Patients were randomized to receive 10 mg/day SR27417A or placebo, and both groups were also given 2.4 g mesalazine. Patient classification at the end of the treatment period was based on sigmoidoscopy and clinical scores. One hundred fifty-one subjects entered the study (75 placebo and 76 SR27417A). The remission rate between placebo- and SR27417A-treated patients at 28 days was not significantly different (29.0% and 35.6% respectively; P = 0.44). Similarly, 49.2% treated with SR27417A had a definite or possible improvement of their symptom score compared with 48.3% of those treated with placebo (P = 0.43). Four subjects in the placebo group and 5 subjects in the SR27417A group discontinued the drug treatment because of adverse events. No significant adverse events were thought to be caused by SR27417A. Although the specific PAF antagonist SR27417A is safe in humans, there is no evidence of efficacy in the treatment of acute ulcerative colitis.