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Rifaximin in Patients With Monoclonal Gammopathy

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details. Identifier: NCT03820817
Recruitment Status : Recruiting
First Posted : January 29, 2019
Last Update Posted : October 19, 2021
The Leukemia and Lymphoma Society
Information provided by (Responsible Party):
Madhav Dhodapkar, Emory University

Brief Summary:
This trial studies how well rifaximin works in treating patients with monoclonal gammopathy. Antibiotics, such as rifaximin, may help to kill bacteria in the intestines and reduce the abnormal protein or cells in patients with monoclonal gammopathy.

Condition or disease Intervention/treatment Phase
IgA Monoclonal Gammopathy IgG Monoclonal Gammopathy IgM Monoclonal Gammopathy Light Chain Deposition Disease Monoclonal Gammopathy Smoldering Waldenstrom Macroglobulinemia Waldenstrom Macroglobulinemia Gammopathy, Monoclonal Gammopathy Igg Drug: Rifaximin Phase 1

Detailed Description:


I. To evaluate the effect of a 2-week course of rifaximin on clonal immunoglobulin (Ig) in patients with monoclonal gammopathy.


I. To evaluate safety and tolerability of a 2-week course of rifaximin.

II. To evaluate changes in stool microbiota by 16S ribosomal ribonucleic acid (rRNA) gene (16S) sequencing.

III. To evaluate changes in gammopathy as assessed by changes in clonal Ig and/or plasma cells.


Patients receive rifaximin orally (PO) thrice daily (TID) on days 1-14 in the absence of disease progression or unacceptable toxicity.

After completion of study treatment, patients are followed for 8 weeks.

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 48 participants
Allocation: N/A
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Pilot Study of Oral Rifaximin in Patients With Monoclonal Gammopathy
Actual Study Start Date : May 15, 2019
Estimated Primary Completion Date : November 30, 2022
Estimated Study Completion Date : November 30, 2022

Arm Intervention/treatment
Experimental: Treatment (rifaximin)
Patients receive rifaximin PO TID on days 1-14 in the absence of disease progression or unacceptable toxicity.
Drug: Rifaximin
Given PO
Other Name: Xifaxan

Primary Outcome Measures :
  1. Clinical response rate defined as a reduction in clonal immunoglobulin (Ig) by > 25% [ Time Frame: Up to 2 weeks after study start ]
    Clinical response rate will be calculated as proportion (responders/total patients).

Secondary Outcome Measures :
  1. Incidence of adverse events graded according to Common Terminology Criteria for Adverse Events (CTCAE) version 4.0 [ Time Frame: Up to 12 weeks after study start ]
    Incidence of adverse events (AEs) occurring during the study will be summarized by system organ class and preferred term. Adverse events will also be summarized by causality and grade. Serious adverse events will be listed separately.

  2. Changes in stool microbiota [ Time Frame: Up to 12 weeks after study start ]
    16S sequencing will be used to compare changes in stool microbiota.

  3. Changes in gammopathy [ Time Frame: Up to 12 weeks after study start ]
    Changes in clonal Ig will be used to assess changes in gammopathy.

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Clinical diagnosis of monoclonal gammopathy of undetermined significance based on International Myeloma Working Group (IMWG) criteria
  • Patients will be enrolled into one of 3 cohorts:

    • Cohort A: IgA gammopathy
    • Cohort B: IgG gammopathy / or light chain gammopathy
    • Cohort C: IgM gammopathy / asymptomatic macroglobulinemia
  • Ability to understand and the willingness to sign a written informed consent document

Exclusion Criteria:

  • Patients who have received antibiotics within last 3 weeks
  • Patients who are receiving any other investigational agents for gammopathy. Patients with clinical myeloma requiring anti-myeloma therapy are also excluded
  • History of allergic reactions or intolerance attributed to rifaximin or compounds of similar chemical or biologic composition to antibiotic under study
  • The effects of rifaximin on the developing human fetus are unknown. For this reason, women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation. Should a woman become pregnant or suspect she is pregnant while she or her partner is participating in this study, she should inform her treating physician immediately. Men treated or enrolled on this protocol must also agree to use adequate contraception prior to the study, for the duration of study participation, and 4 months after completion of rifaximin administration

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT03820817

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Contact: Madhav Dhodapkar, MD 404-778-4191

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United States, Georgia
Emory University Hospital/Winship Cancer Institute Recruiting
Atlanta, Georgia, United States, 30322
Contact: Shondolyn Richburg    404-778-3612   
Contact: Eduardo Sanabria    404-778-2164   
Sponsors and Collaborators
Emory University
The Leukemia and Lymphoma Society
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Principal Investigator: Madhav Dhodapkar, MD Emory University
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Responsible Party: Madhav Dhodapkar, Principal Investigator, Emory University Identifier: NCT03820817    
Other Study ID Numbers: IRB00106380
NCI-2018-02106 ( Registry Identifier: CTRP (Clinical Trial Reporting Program) )
Winship4480-18 ( Other Identifier: Emory University Hospital/Winship Cancer Institute )
First Posted: January 29, 2019    Key Record Dates
Last Update Posted: October 19, 2021
Last Verified: October 2021
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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Studies a U.S. FDA-regulated Drug Product: Yes
Studies a U.S. FDA-regulated Device Product: No
Additional relevant MeSH terms:
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Waldenstrom Macroglobulinemia
Monoclonal Gammopathy of Undetermined Significance
Neoplasms, Plasma Cell
Neoplasms by Histologic Type
Hemostatic Disorders
Vascular Diseases
Cardiovascular Diseases
Blood Protein Disorders
Hematologic Diseases
Hemorrhagic Disorders
Lymphoproliferative Disorders
Lymphatic Diseases
Immunoproliferative Disorders
Immune System Diseases
Anti-Bacterial Agents
Anti-Infective Agents
Gastrointestinal Agents