Objective: This open-label study was conducted as a preliminary assessment of rifaximin (200 mg TID for 16 weeks) for the treatment of active Crohn's disease in patients (n = 29) with symptoms for at least 3 months before screening and a Crohn's Disease Activity Index (CDAI) score > 220 and < 400.
Results: At the end of month 4, mean +/- CDAI score was reduced by 43% compared with baseline in the intent-to-treat population (n = 29; baseline = 278 +/- 51; month 4 = 159 +/- 102; p < 0.0001 month 4 versus baseline). A similar pattern of results was observed in the per-protocol population (i.e., patients at least 70% compliant with the treatment regimen and having no protocol violations thought to affect efficacy results; n = 16), in which mean CDAI scores at month 4 were reduced by 41% from a baseline of 262.9 +/- 38.2 to 155.6 +/- 104.5 (p = 0.0009 month 4 versus baseline). Fifty-nine percent of patients (59%) had a > or = 70-point improvement in CDAI score beginning with the first assessment at the end of month 1. By the end of the treatment period, 78% of patients had a > or = 70-point improvement in CDAI score. Clinical remission, defined as CDAI score < 150, was observed at the end of treatment months 1, 2, 3, and 4 in 41%, 56%, 56%, and 59% of patients, respectively. Twenty-three (23) patients completed the 4-month course of rifaximin therapy, and 6 prematurely withdrew. The most common adverse events were abdominal pain, fatigue, and headache.
Conclusion: These data, which are consistent with the possibility that rifaximin may be useful for active Crohn's disease, warrant confirmation in a randomized, double-blind, placebo-controlled trial.