The Effect of Rifabutin in Mycobacterium Abscessus With Inducible Clarithromycin Resistance

June 8, 2026 updated by: National Taiwan University Hospital

The Effect of Rifabutin in Mycobacterium Abscessus With Inducible Clarithromycin Resistance: a Randomized Study

Background: Mycobacterium abscessus, one of the most common species of nontuberculous mycobacterium (NTM), poses a significant clinical challenge due to its natural resistance to antibiotics and high treatment failure rates, particularly in lung diseases. Among its subspecies, M. abscessus subspecies abscessus is especially prone to developing inducible resistance to Clarithromycin. This resistance mechanism is primarily due to the activation of the erm(41) gene,which inhibits Clarithromycin from effectively binding to the bacterial ribosome, diminishing its bactericidal efficacy. Rifabutin, an antibiotic widely used in treating tuberculosis and certain NTM infections, has been shown to inhibit the activation of the erm(41) gene by suppressing the whiB7 protein in M. abscessus, suggesting potential efficacy against inducible resistance. However,current evidence primarily stems from in vitro susceptibility studies and case reports, with a notable lack of systematic clinical trials.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Specific Aims: The primary aim of this study is to evaluate the efficacy and safety of Rifabutin in treating M. abscessus lung disease with inducible Clarithromycin resistance. Specific objectives include:

  • Assessing sputum culture conversion rates and clinical improvement when Rifabutin is added to the standard treatment regimen.
  • Investigating the effect of Rifabutin on progression-free survival (PFS).
  • Evaluating patient tolerance and adverse events throughout treatment.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
60

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Taiwan
      • Taipei, Taiwan
        • Recruiting
        • National Taiwan University Hospital
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Adults aged ≥ 18 years
  • Diagnosis of pulmonary disease caused by Mycobacterium abscessus confirmed by clinical evaluation and laboratory results
  • Antimicrobial susceptibility testing indicating inducible resistance to clarithromycin
  • Clinically stable and suitable for antibiotic treatment
  • Radiographic evidence of active pulmonary infection
  • Willing and able to provide informed consent

Exclusion Criteria:

  • Known hypersensitivity to rifabutin or intolerance to other study medications
  • Pregnant or breastfeeding women

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Treatment Group
Standard Rifabutin dose group: Oral administration once daily, with dosage adjusted based on the patient's body weight and hepatic/renal function; typically 300 mg, combined with standard therapy.
Drug: Rifabutin
The treatment group (received standard treatment plus Rifabutin, with the dosage adjusted according to weight and renal function)
Experimental: Control Group
Standard therapy: Amikacin, Imipenem, Tigecycline, Linezolid, and Clarithromycin or Azithromycin.
Drug: No Rifabutin
the control group (received standard treatment only).

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
In the study period, we have screened 286 patients with kidney transplant and enrolled 50 participants who were KTR and had LTBI.
Time Frame: 2years
In the study period, we have screened 286 patients with kidney transplant and enrolled 50 participants who were KTR and had LTBI. Among them, 24 received 9H regimen, 10 had 3HR, one underwent 3HP, one used 4R, and the remaining 14 declined LTBI treatment. Finally, there were 36 patients received LTBI treatment. Regarding ADRs, there was no severe ADR, but 3 of 3HR group had mild (Grade 1) non-specific reaction of malaise, which was borderline higher than 9H group (25% vs 0%, p=0.025). The effect on FK506 by rifamycin was all adjustable except one using 3HP regimen. There was no kidney injury found. The dosage of FK506 needed to titrated up to around two-fold. Only one of 9H group had interrupted LTBI treatment course due to other cause. The incompletion rate was insignificant difference between 9H and 3HR groups (4% vs 0%, p=667). 3HR regimen cost less and patients had lower clinic return times compared with 9H group.
2years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
National Taiwan University Hospital

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 1, 2026

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
March 1, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
June 18, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
March 20, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 31, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
April 7, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
June 10, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 8, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
January 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 202411007MINA

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Cookie Settings

We use cookies to ensure that we give you the best experience on our website. For more details carefully read our Privacy and Cookies Policy. ...>>>You can change your preferences or withdraw your consent at any time by deleting the cookies from your website or computer as described in the policy. Please accept it and choose your preferences by ticking the corresponding boxes in the "Manage Settings" section below. Please carefully read our Terms of Service before you proceed with using any part of this website.
«Manage Settings