IBS-D antibiotic Xifaxan shows promise in severe Crohn’s disease

LAS VEGAS — Patients with moderate-to-severe Crohn’s disease achieved clinical response with Xifaxan, an antibiotic with limited systemic absorption approved for the treatment of diarrhea-predominant irritable bowel syndrome, according to new research presented at the Crohn’s & Colitis Congress.

Investigators reported a fourfold greater response with Xifaxan (rifaximin; Salix) compared with placebo, and that response was achieved even among patients with significant disease burden and prior exposure to biologics.

“These results offer renewed hope for the use of antibiotics in treating Crohn’s disease,” according to a media release from the Crohn’s and Colitis Foundation and the American Gastroenterological Association.

Prior studies have shown varying results in treating Crohn’s disease with antibiotics, and studies of rifaximin have shown promise in mild-to-moderate Crohn’s. However, studies of rifaximin in moderate-to-severe luminal Crohn’s disease are lacking.

Therefore, Scott D. Lee, MD, of University of Washington Medicine, and colleagues performed a double-blind randomized controlled crossover trial in which they assigned 24 patients with moderate-to-severe Crohn’s to receive 550 mg rifaximin by mouth twice daily (n = 13) or placebo (n = 11) for 8 weeks, after which placebo non-responders received open-label rifaximin for another 8 weeks.

Among the treatment group, 7.1% of patients had stricturing disease, 30.8% had penetrating disease, and 76.9% had been previously exposed to a biologic.

After the first 8-week treatment period, 38.5% of those who received rifaximin achieved clinical response based on the Crohn’s Disease Activity Index vs. 9.1% of controls (P = .055).

Five of 10 participants with non-response to placebo completed the open-label study, while four stopped early due to lack of efficacy and one withdrew consent. After 8 weeks, one participant achieved clinical response, and none achieved remission.

The investigators noted improvements in quality of life and biochemical assessments — including C-reactive protein and erythrocyte sedimentation rate — among patients treated with rifaximin, but these did not reach statistical significance. Additionally, both study groups showed comparable adverse events, and no new safety concerns emerged.

Lee and colleagues concluded that rifaximin showed “a moderate impact on clinical disease activity” in this patient population. – by Adam Leitenberger

Reference:

Lee S, et al. P142. Presented at: Crohn’s & Colitis Congress; Jan. 19-20, 2018; Las Vegas, NV.

Disclosures: Lee reports financial relationships with Pfizer, Atlantic Pharmaceuticals, Gilead Sciences, Tetherex Pharmaceuticals, Arena Pharmaceuticals, Shield Therapeutics, UCB Pharma, Mesoblast, Cornerstones, Salix Pharmaceuticals, Takeda Pharmaceuticals, Eli Lilly and Company, Celltrion Healthcare, AbbVie, Janssen and Celgene. Please see the full abstract for all authors’ relevant financial disclosures.