Fred Hutch/University of Washington Cancer Consortium
Seattle, Washington, 98109, United States
Location status: Recruiting
Location contact
Madhav Dhodapkar, MBBS
CONTACT
Madhav Dhodapkar, MBBS
PRINCIPAL_INVESTIGATOR
Recruiting
NCT Number: NCT07209371
Rifaximin Versus No Intervention for the Treatment of IgA Monoclonal Gammopathy of Undetermined Significance
This phase II trial compares the effect of rifaximin to no intervention for the treatment of IgA monoclonal gammopathy of undetermined significance (MGUS). Rifaximin is a type of antibiotic that is only used in cancer chemotherapy (antineoplastic antibiotic). It works by damaging the cell's DNA and may kill cancer cells or precancerous cells like those found with MGUS. Giving rifaximin may kill more precancerous cells in patients with IgA MGUS.
Recruiting
Interested in participating?
Request InfoKey information
Age range
18 year and older
Sex eligibility
All sexes
Study type
Interventional
Phase
Phase 2
Primary location
About this study
OUTLINE: Patients are randomized to 1 of 2 arms.
ARM A: Patients receive rifaximin orally (PO) three times daily (TID) for 14 days in the absence of disease progression or unacceptable toxicity. Patients undergo blood sample collection throughout the study.
ARM B: Patients undergo blood sample collection throughout the study.
After completion of study intervention, patients are followed up at 90 days.
Who can participate
Healthy volunteers accepted: No
Only the study team can determine whether someone qualifies for participation.
Inclusion criteria
- Age ≥ 18 years
- Ability to understand and willingness to sign a written informed consent document. Legally authorized representatives may sign and give informed consent on behalf of potential study participants
- Clinical diagnosis of IgA monoclonal gammopathy of undetermined significance (MGUS) based on International Myeloma Working Group (IMWG)-2014 criteria (Rajkumar et al, Lancet Oncology, 2014)
- Agree to use adequate contraception
- For women of child-bearing potential: prior to study entry and for the duration of study participation
- For men: prior to study entry, for the duration of study participation, and one month after completion of rifaximin administration (for men)
- No antibiotic use in the preceding 2 weeks
Exclusion criteria
- Participants who are receiving other investigational agents
- Pregnant women
- Known hypersensitivity to rifaximin
Treatment and study plan
Rifaximin
DrugGiven PO
Other names: Xifaxan
Biospecimen Collection
ProcedureUndergo blood sample collection
Other names: Biological Sample Collection, Biospecimen Collected, Specimen Collection
Primary outcomes
-
Overall response rate
Time frame: From the start of therapy, up to 90 days
Defined as the proportion of patients with > 25% decline in clonal Ig at any point within 90 days after the initiation of drug or no intervention. Logistic regression will be conducted to evaluate the association between endpoint of interest and treatment (Arm A versus [vs] B).
Secondary outcomes
-
Proportion of patients experiencing > grade 2 adverse events
Time frame: From the start of therapy, up to 90 days
Logistic regression will be conducted to evaluate the association between endpoint of interest and treatment (Arm A vs B).
Study contacts
Contact information is provided by the study sponsor or research team.
Sponsors and collaborators
Lead sponsor
Fred Hutchinson Cancer Center
Other
Collaborators
- Rising Tide Foundation
Registry information
Official study title
Rifaximin Versus No Intervention in Patients With IgA Monoclonal Gammopathy of Undetermined Significance
Important dates
- Study start
- 2026
- Primary completion
- 2028
- Study completion
- 2028
- First posted
- Oct 7, 2025
- Registry last updated
- Apr 20, 2026
OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.
View the official ClinicalTrials.gov record (opens in a new tab)This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.