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Comparison of Two- Versus Three-antibiotic Therapy for Pulmonary Mycobacterium Avium Complex Disease

Comparison of Two- Versus Three-antibiotic Therapy for Pulmonary Mycobacterium Avium Complex Disease

Status
Completed
Phases
Phase 2Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT03672630
Acronym
MAC2v3
Enrollment
474
Registered
2018-09-14
Start date
2019-02-22
Completion date
2026-01-08
Last updated
2026-02-02

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Mycobacterium Avium Complex, Nontuberculous Mycobacterium Infection

Keywords

NTM, MAC, mycobacteria, nontuberculous mycobacteria, azithromycin, ethambutol, rifampin

Brief summary

NTM therapy consists of a multi-drug macrolide based regimen for 18-24 months. Treated patients frequently experience debilitating side effects, and many patients delay the start of antibiotic treatment due to these risks. Common side effects include nausea, diarrhea, and fatigue, and rare but serious toxicities include ocular toxicity, hearing loss, and hematologic toxicity. To date, most of the evidence underlying the current treatment recommendations has come from observational studies in which either a macrolide has been combined with rifampin and ethambutol, or in some cases combined with ethambutol alone. The proposed study will answer whether a third drug is necessary or whether taking two drugs can increase tolerability without a substantial loss of efficacy.

Detailed description

Mycobacterium avium complex (MAC) are a subset of nontuberculous mycobacteria (NTM), environmental bacteria that can cause chronic, debilitating pulmonary disease, primarily affecting those over age 60. The goals of treatment are to improve symptoms, stop disease progression, and clear the infection. We propose to address a longstanding controversy in the therapy of pulmonary MAC disease, whether patients must take three antibiotics concomitantly, or if two are sufficient. The study is a multicenter randomized pragmatic clinical trial to compare azithromycin + ethambutol (2-drug therapy) vs. azithromycin + ethambutol + rifampin (3-drug therapy) for non-cavitary pulmonary MAC disease. All clinical outcomes will be considered standard of care and abstracted from clinical records. Therapy changes and adverse events will be recorded at routine visits. Health-related quality of life (HRQoL) and self-reported toxicity will be captured centrally in a web-based database, and CT scans will be read centrally. Co-primary outcomes are culture conversion and tolerability of treatment. The primary analysis for culture conversion will be conducted as a per-protocol non-inferiority analysis, and the primary analysis for tolerability will be conducted as an intention-to-treat superiority analysis.

Interventions

DRUGAzithromycin

Azithromycin 500 MG Oral Tablet \[ZITHROMAX\]

DRUGEthambutol

Ethambutol 25 mg/kg \[MYAMBUTOL\]

DRUGRifampin

Rifampin 600 MG \[RIFADIN\]

Sponsors

Kevin Winthrop
Lead SponsorOTHER
Patient-Centered Outcomes Research Institute
CollaboratorOTHER
National Jewish Health
CollaboratorOTHER
The University of Texas Health Science Center at Tyler
CollaboratorOTHER
University Health Network, Toronto
CollaboratorOTHER
New York University
CollaboratorOTHER
Medical University of South Carolina
CollaboratorOTHER
Mayo Clinic
CollaboratorOTHER
Louisiana State University Health Sciences Center in New Orleans
CollaboratorOTHER
University of California, San Diego
CollaboratorOTHER
Stanford University
CollaboratorOTHER
University of Kansas
CollaboratorOTHER
Vancouver Clinic
CollaboratorUNKNOWN
University of California, San Francisco
CollaboratorOTHER
University of Washington
CollaboratorOTHER
Johns Hopkins University
CollaboratorOTHER
University of Miami
CollaboratorOTHER
Emory University
CollaboratorOTHER
University of Iowa
CollaboratorOTHER
University of North Carolina
CollaboratorOTHER
Temple University
CollaboratorOTHER
Loma Linda University
CollaboratorOTHER
Columbia University
CollaboratorOTHER
University of Wisconsin, Madison
CollaboratorOTHER
Northwell Health
CollaboratorOTHER
Kaiser Permanente
CollaboratorOTHER
James A. Haley Veterans Administration Hospital
CollaboratorFED

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* Culture positive pulmonary MAC meeting ATS/IDSA disease criteria * Age over 18 years * Ability to provide informed consent

Exclusion criteria

* Fibrocavitary disease * Planned surgery for MAC disease * Patients who have cumulatively taken 6 weeks or more of multi-drug antimicrobial treatment for MAC * Patients who are currently taking or have taken multi-drug antimicrobial treatment for NTM within the prior 30 days * Diagnosis of Cystic fibrosis * Diagnosis of HIV * History of solid organ or hematologic transplant * Significant drug-drug interaction not clinically manageable in the opinion of the investigator * Contraindication to any component of the study treatment regimen

Design outcomes

Primary

MeasureTime frameDescription
Acid-fast bacilli (AFB) culture negativity12 months post randomizationTwo consecutive negative AFB cultures by 12 months post randomization without reversion to positive
Therapy completion12 months post randomizationThe proportion of patients who complete 12 months of therapy on their assigned regimen with "satisfactory adherence". "Satisfactory adherence" is defined as taking 80% of their prescribed doses/not missing more than 75 days of treatment.

Secondary

MeasureTime frameDescription
QOL-B Respiratory Symptoms Score12 months post randomizationQuality of Life-Bronchiectasis (QOL-B) with NTM module The QOL-B is a self-administered questionnaire that has been validated in patients with bronchiectasis. The questionnaire measures 8 separate domains: Physical Functioning, Role Functioning, Vitality, Emotional Functioning, Social Functioning, Treatment Burden, Health Perceptions, and Respiratory Symptoms.
NTM Symptoms Score12 months post randomizationQuality of Life-Bronchiectasis (QOL-B) with NTM module The QOL-B is a self-administered questionnaire that has been validated in patients with bronchiectasis. The NTM module includes 4 additional domains: Eating Problems, Body Image, Digestive Symptoms, and NTM Symptoms. No total score is calculated.
PROMIS Fatigue 7a short form score12 months post randomizationPROMIS Fatigue 7a short form score The PROMIS Fatigue item banks assess a range of self-reported symptoms over the past seven days, from mild subjective feelings of tiredness to an overwhelming, debilitating, and sustained sense of exhaustion that likely decreases one's ability to execute daily activities and function normally in family or social roles. Fatigue is divided into the experience of fatigue (frequency, duration, and intensity) and the impact of fatigue on physical, mental, and social activities. Each question has five response options ranging in value from one to five. To find the total raw score for a short form with all questions answered, sum the values of the response to each question. The lowest possible raw score (indicating the highest subjective level of fatigue) is 7; and the highest possible raw score (indicating the lowest subjective level of fatigue) is 35.
Fatigue AE proportionCumulative to 12 monthsSelf-report, Moderate or worse
Gastrointestinal AE proportionup to 12 monthsSelf-report, Moderate or worse: Nausea, diarrhea, decreased appetite, OR abdominal pain
Liver AE proportionup to 12 monthsLaboratory grade 2 or higher abnormality
Macrolide resistance12 months post randomizationSusceptibility at last positive culture

Countries

Canada, United States

Contacts

STUDY_DIRECTOREmily Henkle, PhD, MPH

Oregon Health and Science University

PRINCIPAL_INVESTIGATORKevin L Winthrop, MD, MPH

Oregon Health and Science University

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 12, 2026