Intradiscal rhGDF-6 for the Treatment of Lumbar Disc Degeneration (CBT005)

June 21, 2026 updated by: Cartago Biotech Pty Ltd

A Phase I/II, Open-label, Single Administration Clinical Trial to Evaluate the Safety, Tolerability and Preliminary Efficacy of Intradiscal rhGDF-6 for the Treatment of Lumbar Disc Degeneration

The goal of this clinical trial is to find out if a new medicine can help people who have long-lasting back pain caused by damaged spinal discs. The study will also check if the medicine is safe to use.

The main questions this study aims to answer are:

Is the medicine safe, and what amount works best? Can it reduce long-term back pain?

Researchers will test a medicine called CBT005, which contains a healing protein, by injecting it into the spinal discs. They will watch closely to see how people respond to the treatment.

Participants will:

Receive one study injection into the spinal disc Visit the clinic in person during the first 12 months for checkups Receive phone calls at 24 and 36 months to see how they are doing Still be able to get other pain treatments in the future, including surgery, if needed

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet 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.

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 2
  • Phase 1

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 Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • Australia
    • New South Wales
      • Kogarah, New South Wales, Australia, 2217
        • Spine & Scoliosis Service
        • 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

  1. Persistent low back pain, with at least 3 months of non-surgical therapy, at one symptomatic disc or two symptomatic lumbar disc levels (from L2 to S1).
  2. MRI scans show Pfirrmann disc degeneration grade 2 to 4 or High Intensity Zone (HIZ) signal change with or without Modic endplate changes.
  3. Symptoms are a fair bit or a lot bothersome, which require medication or other types of treatments or very disrupting (in response to question*).
  4. Preoperative Oswestry Disability Index (ODI) score greater than or equal to 30%
  5. Visual Analog Score for back pain ≥40 mm.
  6. Any gender, 18 years of age or older
  7. Clinician diagnosed discogenic pain
  8. A signed HREC-approved Informed Consent Form
  9. Able to meet the protocol follow-up schedule and activities
  10. Females of childbearing potential must have a negative urine/serum pregnancy test at screening (Baseline Visit) and on the day of administration prior to injection *Question defined in full protocol

Exclusion Criteria

  1. People unable to have an MRI
  2. Abnormal neurological exam at baseline (e.g., chronic radiculopathy)
  3. Active radicular pain due to anatomical compression such as stenosis or disc herniation
  4. Symptomatic facet joints and/or severe facet degeneration at the index level or adjacent segments
  5. Symptomatic Sacro-iliac joint
  6. MRI findings demonstrate any of the following: Suspected disc appears normal or >50% decrease in disc height or Presence of symptomatic osteophytes
  7. Any prior lumbar spinal surgeries at suspected symptomatic level; prior surgery at the adjacent levels is acceptable including fusion or arthroplasty, provided the said adjacent level is not independently symptomatic.
  8. Presence of spondylolisthesis (anterolisthesis, retrolisthesis is acceptable)
  9. Symptomatic disc degeneration at more than 2 lumbar levels (multi-level disc degeneration based on MRI findings is acceptable with up to two symptomatic level. Only the symptomatic levels will be treated)
  10. Evidence of active infection
  11. Immunosuppressive therapy within 3 months prior to investigational product administration
  12. Either continuous or cumulative use of more than 2 months use in the past 6 months of an oral or systemic steroid. Inhaled steroids are acceptable
  13. Tumor in the spine
  14. People with any current and previous cancer. An exemption to this is previous BCCs which have been successfully removed.
  15. Non-contained herniated nucleus pulposus
  16. Any prior intradiscal therapies (chemonucleolysis, IDET, intradiscal steroid injection) at the same level being treated, other than rhGDF-6.
  17. Any non-intradiscal steroid injection less than 2 months prior to administration. Does not include isolated joint injections outside the lumbar region.
  18. Nerve block injection less than 2 months prior to injection of study medication.
  19. Known autoimmune disease
  20. Type 1 Insulin-dependent diabetes mellitus (Type II, non-insulin dependent diabetes mellitus is allowed)
  21. Pregnant or lactating, or wishes to become pregnant within the first 12 months of the study
  22. Involved in pending litigation of the spine (including workers compensation cases)
  23. Demonstrates signs of non-organic pain (e.g., Waddell's Signs)
  24. Based on clinical history, physical examination and participant presentation, participant has, or is suspected to have, a history of alcohol and/or drug abuse that would preclude participants from providing adequate consent and/or complying with study requirements
  25. Prisoner
  26. Morbid Obesity, defined as Body Mass Index (BMI) ≥40
  27. Life expectancy less than 2 years
  28. Any significant psychological disturbance past or present, that could impair the consent process or ability to complete participant self-report questionnaires
  29. Any reason not cited above that, in the opinion of the Principal Investigator, would pose a risk to either the participant or to the integrity of the clinical trial

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.
Active Comparator: Low dose
2mg dose of Growth differentiation factor 6
Biological: Low Dose
Low dose: 2mg dose of Growth differentiation factor 6
Active Comparator: High dose
4mg dose of Growth differentiation factor 6
Biological: High Dose
High Dose: 4 mg dose of Growth differentiation factor 6

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
Neurological Status
Time Frame: From enrollment through to 12 months
Safety will be evaluated by assessing neurologic status and the type, frequency, and severity of adverse events through 12 months.
From enrollment through to 12 months
Oswestry Disability Index (ODI)
Time Frame: Enrollment through to 12 months
The Oswestry Disability Index (ODI) assesses functional limitations in activities of daily living related to back pain. The ODI consists of 10 questions, each addressing a specific aspect of daily living affected by back pain, such as pain intensity, personal care, lifting, walking, sitting, standing, sleeping, sexual activity, social life, and travel. Each question has six statements that correlate to a score of 0 to 5. The patient chooses the statement that best describes their current condition, with higher scores indicating greater disability. The total score is calculated by summing the individual question scores and then dividing by the total possible score (which is 50) and multiplying by 100 to get a percentage disability.
Enrollment through to 12 months

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Visual Analog Scale
Time Frame: From enrollment through to 12 months
VAS will be meausred on a millimeter (mm) scale. It is a 100-mm continuous line used to measure subjective experiences like pain, fatigue, or quality of life. Scores will be calculated by measuring the distance in millimeters from the left anchor (usually "no symptom") to the patient's mark.
From enrollment through to 12 months
EQ5D-5L
Time Frame: From enrollment through to 12 months
The EQ-5D-5L is a widely used generic health-related quality of life instrument developed in the 1980s by the EuroQol Group to assess and compare health status across different diseases and populations. An EQ-5D 5L health state is converted into a utility score by subtracting the weighted values assigned to the selected levels in each of the five health dimensions from a baseline of 1. The weights assigned to each level within the health dimensions reflect the relative impact of those health problems on overall quality of life.
From enrollment through to 12 months

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.
Cartago Biotech Pty Ltd

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 (Estimated)

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.
July 4, 2026

Primary Completion (Estimated)

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.
August 31, 2028

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.
December 1, 2030

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).
June 1, 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.
June 21, 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.
June 25, 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 25, 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 21, 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.
June 1, 2026

More Information

Terms related to this study

Keywords

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.
  • 001-CBT-005 Intradiscal rhGDF6

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

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.

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