Rifaximin for Microscopic Colitis

Overseen By Eugene Yen, MD

Age: 18+

Sex: Any

Trial Phase: Phase 2

Sponsor: Eugene F Yen, MD

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Prior Safety Data This treatment has passed at least one previous human trial

Approved in 6 Jurisdictions This treatment is already approved in other countries

Compensation: Varies

Number of Visits: Unknown

Duration: 4 weeks

10 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests whether the drug rifaximin can treat microscopic colitis, a condition causing frequent diarrhea due to colon inflammation. The study aims to evaluate the effectiveness and safety of rifaximin for individuals with either collagenous colitis or lymphocytic colitis. Participants must have a diagnosis of one of these colitis types through colon biopsies and currently experience frequent loose stools. Those with these symptoms and a diagnosis of microscopic colitis may find this trial suitable. As a Phase 2 trial, the research focuses on assessing the treatment's effectiveness in an initial, smaller group of participants.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications. It's best to discuss this with the trial coordinators or your doctor.

Is there any evidence suggesting that rifaximin is likely to be safe for humans?

Research has shown that rifaximin is generally safe and well-tolerated. In studies, some patients took rifaximin for over a year without serious problems. Minor side effects like nausea and headaches can occur, but they are uncommon.

The FDA has already approved rifaximin for treating conditions like traveler's diarrhea and a liver-related brain disorder, indicating it has passed safety checks for those uses. Although it is now being tested for a new condition, its previous approvals suggest it is likely safe for most people. ^{1 2 3 4 5}

Why do researchers think this study treatment might be promising for colitis?

Unlike the standard treatments for microscopic colitis, which typically include corticosteroids and anti-inflammatory medications, rifaximin offers a unique approach. Rifaximin is an antibiotic that primarily stays in the gut, which means it can target inflammation locally without significant absorption into the bloodstream, potentially reducing side effects. Researchers are excited about rifaximin because it could offer a safer and well-tolerated alternative that specifically targets gut bacteria, potentially leading to better management of symptoms with fewer systemic effects.

What evidence suggests that rifaximin might be an effective treatment for microscopic colitis?

Research has shown that rifaximin, which participants in this trial will receive, effectively treats irritable bowel syndrome with diarrhea (IBS-D), a condition with symptoms similar to microscopic colitis. Studies indicate that rifaximin can significantly reduce stomach pain and diarrhea, with more than two-thirds of patients experiencing improvement. About 80% of those who initially feel better continue to experience relief. These findings suggest that rifaximin might help manage microscopic colitis symptoms by reducing inflammation and improving gut health. ^{6 7 8 9 10}

Who Is on the Research Team?

Eugene Yen, MD

Principal Investigator

Endeavor Health

Are You a Good Fit for This Trial?

Inclusion Criteria

Collagenous colitis (CC) or lymphocytic colitis (LC) diagnosed on colon biopsies reviewed by 2 separate pathologists

CC will be defined histologically to be the following: thickness of the collagenous subepithelial table >10 micrometer using an ocular micrometer, inflammation in the lamina propria consisting of mainly lymphocytes and plasma cells, lack of crypt architectural distortion, and regenerative-appearing changes in the surface and/or crypt epithelium

LC will be defined histologically to be the following: intraepithelial lymphocytes >20 per 100 epithelial cells in the subjective area of highest lymphocyte density, inflammation in the lamina propria consisting of mainly lymphocytes and plasma cells, and regenerative-appearing changes in the surface and/or crypt epithelium

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive open-label rifaximin 550mg three times per day for 4 weeks

4 weeks

Follow-up

Participants are monitored for safety and effectiveness after treatment

2 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Rifaximin

How Is the Trial Designed?

Group I: Drug Experimental Treatment 1 Intervention

Patients will receive open-label rifaximin 550mg tid x 4 weeks.

Rifaximin is already approved in United States, Canada, European Union, India for the following indications:

Approved in United States as Xifaxan for:

• Traveler's diarrhea
• Irritable bowel syndrome with diarrhea
• Hepatic encephalopathy

Approved in Canada as Zaxine for:

• Traveler's diarrhea
• Irritable bowel syndrome with diarrhea
• Hepatic encephalopathy

Approved in European Union as Xifaxan for:

• Traveler's diarrhea
• Irritable bowel syndrome with diarrhea
• Hepatic encephalopathy

Approved in India as Ciboz and Xifapill for:

• Traveler's diarrhea
• Irritable bowel syndrome with diarrhea
• Hepatic encephalopathy

Who Is Running the Clinical Trial?

Eugene F Yen, MD

Lead Sponsor

Trials

1

Recruited

10+

Published Research Related to This Trial

In a study involving 43 patients with liver cirrhosis, both low-dose (800 mg/day) and high-dose (1200 mg/day) rifaximin significantly reduced serum endotoxin levels after 2 weeks, indicating effective management of endotoxemia.

The effects of high-dose rifaximin persisted for at least 4 weeks after treatment cessation, and the safety profile was similar across all groups, suggesting that lower doses may be just as effective without increasing risk.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Does low-dose rifaximin ameliorate endotoxemia in patients with liver cirrhosis: a prospective study. Zeng, X., Tang, XJ., Sheng, X., et al.[2018]

Rifaximin is effective in treating travelers' diarrhea caused by Escherichia coli, showing similar efficacy to ciprofloxacin, but it does not work against Campylobacter jejuni infections.

Beyond travelers' diarrhea, rifaximin has potential uses in treating various gastrointestinal disorders, including hepatic encephalopathy and Crohn's disease, due to its broad spectrum of activity and poor absorption in the gastrointestinal tract.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Rifaximin: a nonabsorbed oral antibiotic. Baker, DE.[2018]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC10558962/

Effectiveness of Rifaximin on the Outcomes of Irritable ... The results of our meta-analysis support the use of rifaximin in the treatment of IBS, owing to its safety and effectiveness.

2. xifaxan.com xifaxan.com/hcp/ibsd/efficacy/

Efficacy Data for Adults with IBS-D In adults with IBS-D. 2 weeks of XIFAXAN provided significant relief of abdominal pain and diarrhea1,2,*. Percentage of composite efficacy responders in ...

3. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC5299503/

Systematic review with meta‐analysis: rifaximin is effective ... Symptoms improved or disappeared in more than two‐thirds of patients (67.7%). However, the sample size was relatively small (205 patients overall) and there was ...

4. aafp.org aafp.org/pubs/afp/issues/2017/0215/p258.html

Rifaximin (Xifaxan) for Irritable Bowel Syndrome Relief of IBS symptoms is sustained for at least 10 weeks following treatment in about 80% of patients who initially responded. If symptoms ...

5. sciencedirect.com sciencedirect.com/science/article/pii/S0149291823000309

Rifaximin Treatment for Individual and Multiple Symptoms ... Rifaximin significantly improved multiple, concurrent IBS-D symptoms, using clinically relevant definitions of treatment response.

6. mayoclinic.org mayoclinic.org/drugs-supplements/rifaximin-oral-route/description/drg-20065817

Rifaximin (oral route) - Side effects & dosage Rifaximin is used to treat traveler's diarrhea that is caused by a bacteria called Escherichia coli. It is also used to prevent hepatic encephalopathy.

7. accessdata.fda.gov accessdata.fda.gov/drugsatfda_docs/label/2017/021361s023lbl.pdf

XIFAXAN® (rifaximin) tablets, for oral use - accessdata.fda.gov The safety of XIFAXAN for the treatment of IBS-D was evaluated in 3 placebo-controlled studies in which 952 patients were randomized to XIFAXAN 550 mg three ...

8. cdn.caymanchem.com cdn.caymanchem.com/cdn/msds/16131m.pdf

Safety Data Sheet 80621-81-4 Rifaximin. · Identification number(s). · EC number: 617-130-4. 4 First-aid measures. · Description of first aid measures. · General ...

9. pubmed.ncbi.nlm.nih.gov pubmed.ncbi.nlm.nih.gov/24365449/

Rifaximin is safe and well tolerated for long-term maintenance ... Results: In the all-rifaximin population, the median exposure to rifaximin was 427.0 days (range, 2-1427 d), with 510.5 person-years of exposure.

10. reference.medscape.com reference.medscape.com/drug/xifaxan-rifaximin-342685

Xifaxan (rifaximin) dosing, indications, interactions, ... rifaximin decreases effects of microbiota oral by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Microbiota oral contains bacterial spores.