Randomized, Double-Blind, Placebo-Controlled Study of Anti-Mycobacterial Therapy (RHB-104) in Active Crohn’s Disease

• Published in: Antibiotics
• Main Authors: David Y. Graham, Saleh A. Naser, Thomas Borody, Zbigniew Hebzda, Harry Sarles, Scott Levenson, Robert Hardi, Tomasz Arłukowicz, Petar Svorcan, Reza Fathi, Aida Bibliowicz, Patricia Anderson, Patrick McLean, Clara Fehrmann, M. Scott Harris, Shuhong Zhao, Ira N. Kalfus
• Format: Article
• Language: English
• Published: MDPI AG 2024-07-01
• Subjects: RHB-104; Crohn’s disease; <i>Mycobacterium avium</i> subspecies <i>paratuberculosis</i>; clinical trial; clarithromycin; rifabutin
• Online Access: https://www.mdpi.com/2079-6382/13/8/694

This study, conducted between 4 October 2013, and 30 November 2018, tested the hypothesis that triple antimicrobial therapy, targeting <i>Mycobacterium avium</i> subspecies <i>paratuberculosis</i> (MAP), long considered a putative cause, would favorably affect Crohn’s disease. A double-blind multicenter study of adults with active Crohn’s disease, (i.e., Crohn’s Disease Activity Index [CDAI] 220–450 plus C-reactive protein ≥ 1.0 mg/dL, fecal calprotectin (FCP) >162.9 µg/g stool, or recent endoscopic or radiographic confirmation of active disease) receiving concomitant standard-of-care Crohn’s disease treatment (Clinicaltrials.gov: NCT01951326) were stratified by anti-tumor necrosis factor use and randomized (1:1) to anti-MAP RHB-104 (clarithromycin 95 mg, rifabutin 45 mg, and clofazimine 10 mg per capsule) (n = 166), resulting in clarithromycin 950 mg/day, rifabutin 450 mg/day, and clofazimine 100 mg/day, or placebo (n = 165) for up to 52 weeks. A greater proportion of RHB-104 versus placebo-treated patients met the primary endpoint—remission (i.e., CDAI < 150)—at week 26 (36.7% [61/166] vs. 22.4% [37/165], respectively; 95% CI for difference: 4.6, 24.0, <i>p</i> = 0.0048; chi-square test). Clinical response (reduction of CDAI by ≥100 points from baseline) at week 26 (first secondary endpoint) was also higher among the patients treated with RHB-104 (73/166 [44.0%]) compared with placebo (50/165 [30.3%]; 95% CI for difference: 3.4, 24.0, <i>p</i> = 0.0116), and it remained higher at week 52 among the patients treated with RHB-104 (59/166 [35.5%] vs. (35/165 [21.2%] for placebo; 95% CI for difference: 4.7, 23.9, <i>p</i> = 0.0042). A statistically significantly greater decline in FCP (another prospective efficacy endpoint) was also observed in RHB-104-treated patients, compared with placebo, at weeks 12, 26, and 52. The rates of serious adverse events were similar between groups (RHB-104: 18.7%; placebo: 18.8%). No patient died during the study. Antimicrobial therapy directed against MAP resulted in significantly greater improvement in clinical and laboratory (FCP) measures of active Crohn’s disease.