A placebo-controlled trial of cyclosporine enemas for mildly to moderately active left-sided ulcerative colitis

Background/Aims: Uncontrolled studies suggest that cyclosporine administered as an enema may be of benefit for left-sided ulcerative colitis and safer than intravenous or oral administration. The efficacy and safety of cyclosporine enemas for left-sided ulcerative colitis in a placebo-controlled trial was assessed. Methods: Steroid and mesalamine enemas were withdrawn before the study. Forty patients were assigned to 1 of 4 strata: no concomitant therapy, oral steroids, oral salicylates, or oral steroids and salicylates. After stratification, patients were randomized to nightly treatment with 350 mg cyclosporine (n = 20) or placebo (n = 20) enemas. Clinical response was determined at baseline and 4 weeks by endoscopy, physician assessment, and a patient diary of daily symptoms. Trough blood cyclosporine levels were measured by high-performance liquid chromatography. Results: At 4 weeks, 8 of 20 patients (40%) who received cyclosporine showed clinical improvement compared with 9 of 20 patients (45%) who received placebo. One patient receiving cyclosporine had reversible neutropenia attributable to sulfasalazine, and another patient receiving cyclosporine was unable to tolerate the enema vehicle. No other toxicity was noted during the trial. Blood cyclosporine levels were detectable in only two patients. Conclusions: Cyclosporine enemas administered in a dosage of 350 mg/day for 4 weeks are not efficacious in mildly to moderately active left-sided ulcerative colitis.