Rifaximin Versus No Intervention for the Treatment of IgA Monoclonal Gammopathy of Undetermined Significance

Not Applicable

Not yet recruiting

• Conditions: IgA Monoclonal Gammopathy of Undetermined Significance
• Interventions: Drug: Rifaximin; Procedure: Biospecimen Collection

• Registration Number: NCT07209371
• Lead Sponsor: Fred Hutchinson Cancer Center

Brief Summary

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.

Detailed Description

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.

Study Timeline

• Status Verified: 2025-10
• Study First Submitted: 2025-10-01
• Study First Submitted QC: 2025-10-01
• Last Update Submitted: 2025-10-01
• Study First Posted: 2025-10-07
• Last Update Posted: 2025-10-07
• Study Start: 2026-03-01
• Primary Completion: 2028-05-01
• Study Completion: 2028-05-01

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: All
• Target Recruitment: 50

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Arm A (Rifaximin)	Rifaximin	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 A (Rifaximin)	Biospecimen Collection	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 (No intervention)	Biospecimen Collection	Patients undergo blood sample collection throughout the study.

Primary Outcome Measures

Name	Time	Method
Overall response rate	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 Outcome Measures

Name	Time	Method
Proportion of patients experiencing > grade 2 adverse events	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).

Trial Locations

Locations (1)

Fred Hutch/University of Washington Cancer Consortium; 🇺🇸 Seattle, Washington, United States