Efficacy of Antibiotic Treatment for Patients With Chronic Low Back Pain and Modic Type I Changes - Randomized Placebo-controlled Trial (ABBA)

August 5, 2025 updated by: Bart Koes

The goal of this clinical trial is to learn if antibiotics (amoxicillin) work to treat chronic low back pain in adults. In some patients, this type of back pain may be caused by bacteria in the vertebrae, resulting in a condition known as "Modic type I change."

The main questions the trial aims to answer are:

  • What is the efficacy (primary objective) of antibiotic treatment for patients with chronic low back pain and Modic type I changes?
  • What is the cost-effectiveness (secondary objective) of antibiotic treatment for patients with chronic low back pain and Modic type I changes?

Researchers will compare amoxicillin to a placebo (a look-alike substance that contains no active drug) to see if amoxicillin works to treat chronic low back pain.

Participants in the trial will:

  • Be invited for an MRI scan to determine if they have a Modic type I change; those who do will be included in the study.
  • Take either amoxicillin or a placebo daily for 100 days.
  • Take probiotics daily for 100 days to reduce the occurrence and impact of any side effects from the antibiotics.
  • Attend clinic visits at baseline (the start), 4 weeks, 3 months, and 12 months for checkups and tests.
  • Complete questionnaires at baseline, 3 months, 6 months, and 12 months.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

204

Phase

  • Phase 3

Contacts and Locations

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

Study Contact

Study Locations

  • Netherlands
    • Zuid-Holland
      • Rotterdam, Zuid-Holland, Netherlands, 3015 GD
        • Recruiting
        • Erasmus Medical Center
        • 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

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Aged 18-65 years.
  • Chronic low back pain (i.e. duration >6 months) after a previous (MRI confirmed) disc herniation within the past 6 months to 2 years.

  • At least 2 of the following questions should be answered with "Yes":

    • Does training and/or exercise increase your pain?
    • Is your sleep during the night disturbed due to your back pain?
    • Is it painful to turn over in bed at night?
    • Do you suffer from morning pain?
  • The mean pain intensity should be at least 5 points on a 0-10 NRS-scale, calculated as the mean pain intensity of 3 indices: current pain, worst pain within the preceding two weeks, and the usual mean pain within the preceding two weeks.
  • Modic Type I changes visible on the MRI-scan in the vertebrae adjacent to the previous herniated disc.

Exclusion Criteria:

  • Received antibiotic treatment in the past month.
  • Current pregnancy, lactation or pregnancy-wish.
  • Severe physical or psychiatric co-morbidities.
  • LBP resulting from a specific cause such as a tumor or fracture.
  • Surgery or epidural injection in the past 6 months.
  • Previous antibiotic course of 100 days.
  • Contra-indication for amoxicillin use: allergy to penicillins/amoxicillin, cephalosporin or carbapenem; mononucleosis; leukemia; phenylketonuria (PKU)
  • Contra-indication for MRI.
  • Current use of any of the following medications: allopurinol, methotrexate, phenylbutazone or probenecid.
  • Hepatic or renal (eGFR≤30) impairment.
  • Inability to swallow capsules.

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: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Antibiotic treatment (amoxicillin)
A dose of 1000 mg (3 times a day) for a period of 100 days
Drug: Amoxicillin
Antibiotic treatment (amoxicillin) with a dosage of 1000 mg (3 times a day) for a period of 100 days
Placebo Comparator: Placebo
A dose of 1000 mg (3 times a day) for a period of 100 days
Other: Placebo
Placebo with a dose of 1000 mg (3 times a day) for a period of 100 days

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Roland Morris Disability Questionnaire (RMDQ)
Time Frame: The measurements are scheduled at baseline and at 3, 6 and 12 months follow-up.
The primary outcome is pain and disability measured with the Roland Morris Disability Questionnaire (RMDQ). The scale ranges from 0-24 in which a higher score indicates higher disability. The RMDQ was also the primary outcome in the previous trials, and it is a recommended core outcome measure for trials in LBP.
The measurements are scheduled at baseline and at 3, 6 and 12 months follow-up.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
LBP-intensity (0-10 NRS-scale)
Time Frame: Measured at baseline, 3 months, 6 months and 12 months
In the form of a questionnaire
Measured at baseline, 3 months, 6 months and 12 months
Leg pain intensity (0-10 NRS-scale)
Time Frame: Measured at baseline, 3 months, 6 months and 12 months
In the form of a questionnaire
Measured at baseline, 3 months, 6 months and 12 months
Health-related quality of life (PROMIS-GH-10)
Time Frame: Measured at baseline, 3 months, 6 months and 12 months
In the form of a questionnaire
Measured at baseline, 3 months, 6 months and 12 months
Health-related quality of life (EQ-5D-5L)
Time Frame: Measured at baseline, 3 months, 6 months and 12 months
In the form of a questionnaire
Measured at baseline, 3 months, 6 months and 12 months
Self-reported number of days with sick leave
Time Frame: Measured at baseline, 3 months, 6 months and 12 months
In the form of a questionnaire
Measured at baseline, 3 months, 6 months and 12 months
Co-interventions (pharmacological and non-pharmacological)
Time Frame: Measured at baseline, 3 months and 12 months
In the form of a questionnaire
Measured at baseline, 3 months and 12 months
Global perceived effect (7-point Likert scale)
Time Frame: Measured at 3 months, 6 months and 12 months
In the form of a questionnaire
Measured at 3 months, 6 months and 12 months
Patients' satisfaction with treatment (7-point Likert scale)
Time Frame: Measured at baseline, 3 months and 12 months
In the form of a questionnaire
Measured at baseline, 3 months and 12 months
Success of blinding
Time Frame: Measured at 3 months and 12 months
In the form of a questionnaire
Measured at 3 months and 12 months
Compliance
Time Frame: Measured at 3 months
A pill count will be conducted
Measured at 3 months
Pain self-efficacy (Pain Self-Efficacy Questionnaire)
Time Frame: Measured at baseline, 3 months, 6 months and 12 months
In the form of a questionnaire
Measured at baseline, 3 months, 6 months and 12 months
Sleep questionnaire (Pittsburgh Sleep Quality Index)
Time Frame: Measured at baseline, 3 months, 6 months and 12 months
In the form of a questionnaire
Measured at baseline, 3 months, 6 months and 12 months
Neuropathic pain (PainDETECT)
Time Frame: Measured at baseline, 3 months, 6 months and 12 months
In the form of a questionnaire
Measured at baseline, 3 months, 6 months and 12 months
Cost questionnaires (Medical Consumption Questionnaire)
Time Frame: Measured at 3 months, 6 months and 12 months
In the form of a questionnaire
Measured at 3 months, 6 months and 12 months
Cost questionnaires (Productivity Cost Questionnaire)
Time Frame: Measured at 3 months, 6 months and 12 months
In the form of a questionnaire
Measured at 3 months, 6 months and 12 months
Gut microbiome composition
Time Frame: Measured at baseline, 3 months, and 12 months

The possible collateral impact of antibiotics on the microbiome would be investigated by comparing the abundance and diversity of microbial and resistome composition between patients in amoxicillin and placebo groups. They would be characterized using whole shotgun and functional metagenomic sequencing data (Dhariwal et al. Gut Microbes, 2023).

In short, stools of the patients will be collected at baseline, 3 months, and 12 months. From these samples, the microbial DNA will be extracted using a commercial kit. Libraries for shotgun metagenomic sequencing would be prepared using Ilumina sequencing platform. Low quality and adapter sequences from paired-end reads will be filtered, and human DNA contaminant sequences will be discarded. The high-quality reads will be subjected to taxonomic classification. CARD antimicrobial resistance database will be used to annotate metagenomic reads.
Measured at baseline, 3 months, and 12 months

Collaborators and Investigators

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

Sponsor

Bart Koes

Collaborators

Erasmus University Rotterdam

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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)

April 2, 2025

Primary Completion (Estimated)

August 1, 2027

Study Completion (Estimated)

August 1, 2027

Study Registration Dates

First Submitted

November 21, 2024

First Submitted That Met QC Criteria

January 10, 2025

First Posted (Actual)

January 13, 2025

Study Record Updates

Last Update Posted (Actual)

August 6, 2025

Last Update Submitted That Met QC Criteria

August 5, 2025

Last Verified

August 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2024-515824-35
  • 2024-515824-35-01 (Ctis)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

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.

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