Efficacy and Safety of Rexlemestrocel-L Combined With HA* in Participants With Moderate to Severe Chronic Low Back Pain (HyaluronicAcid)

January 23, 2026 updated by: Mesoblast, Ltd.

A Prospective, Multicenter, Randomized, Double-blind, Controlled Study to Evaluate the Efficacy and Safety of a Single Injection of Rexlemestrocel-L Combined With HA in Subjects With Moderate to Severe Chronic Low Back Pain

The primary purpose of this study is to evaluate the efficacy of rexlemestrocel-L+HA compared to control in reducing low back pain at 12 months post-treatment and safety of a single injection of rexlemestrocel-L+HA injected into a lumbar intervertebral disc compared to control through 12 months post-treatment.

Study Overview

Status

Recruiting

Study Type

Interventional

Enrollment (Estimated)

300

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

    • Arizona
      • Phoenix, Arizona, United States, 85085
        • Recruiting
        • Axsendo Clinical Research/Summa Pain Care
        • Contact:
          • Paul Pannozzo, MD
        • Principal Investigator:
          • Paul Pannozzo, MD
      • Tucson, Arizona, United States, 85710
        • Recruiting
        • Pain Institute of Southern Arizona
        • Contact:
          • Efrain Cubillo, MD
        • Principal Investigator:
          • Efrain Cubillo, MD
    • California
      • Chula Vista, California, United States, 91910
        • Recruiting
        • TriWest Research Associates
        • Contact:
          • Arthur R Mabaquiao, MD
        • Principal Investigator:
          • Arthur Mabaquiao, MD
      • Concord, California, United States, 94520
        • Recruiting
        • Boomerang Health Care
        • Principal Investigator:
          • Kasra Amirdelfan, MD
        • Contact:
          • Kasra Amirdelfan, MD
      • Long Beach, California, United States, 90806
        • Recruiting
        • Memorial Orthopaedic Surgical Group
        • Contact:
          • Philip S Yuan, MD
        • Principal Investigator:
          • Philip S Yuan, MD
      • Newport Beach, California, United States, 92660
        • Recruiting
        • Newport Therapeutics
        • Contact:
          • Rick Paicius, MD
        • Principal Investigator:
          • Rick Paicius, MD
      • Sacramento, California, United States, 95816
        • Recruiting
        • University of California-Davis Spine Center
        • Principal Investigator:
          • Kee Kim, MD
        • Contact:
          • Kee Kim, MD
      • San Diego, California, United States, 92111
        • Recruiting
        • Innovative Pain Treatment Solutions
        • Principal Investigator:
          • Krishnan Chakravarthy, MD, PhD
        • Contact:
          • Krishnan Chakravarthy, MD, PhD
      • San Francisco, California, United States, 94143
        • Recruiting
        • University of California-San Francisco
        • Principal Investigator:
          • conor O'Neill, MD
        • Contact:
          • Conor O'Neill, MD
      • Santa Monica, California, United States, 90403
        • Recruiting
        • Source Healthcare
        • Principal Investigator:
          • Timothy Davis, MD
        • Contact:
          • Timothy Davis, MD
    • Colorado
      • Greenwood, Colorado, United States, 80111
        • Recruiting
        • Colorado Spine Partners/The Denver Spine and Pain Institute
        • Contact:
          • Gary Ghiselli, MD
        • Principal Investigator:
          • Gary Ghiselli, MD
        • Sub-Investigator:
          • Scott Bainbridge, MD
    • Florida
      • Coral Gables, Florida, United States, 33134
        • Recruiting
        • Prime Medical Research
        • Contact:
          • Miguel Telleria, MD, MBA
        • Principal Investigator:
          • Miguel Telleria, MD, MBA
      • Fort Lauderdale, Florida, United States, 33306
        • Recruiting
        • Cantor Spine Center at the Paley Orthopedic & Spine Institute
        • Contact:
          • Anthony Giuffrida, MD
        • Principal Investigator:
          • Anthony Giuffrida, MD
      • Hialeah, Florida, United States, 33012
        • Recruiting
        • New Life Medical Research Center
        • Contact:
          • Raul Falero, MD
        • Principal Investigator:
          • Raul Falero, MD
      • Jacksonville, Florida, United States, 32224
        • Recruiting
        • Bold City Clinical Research
        • Contact:
          • Ferdinand Formoso, DO
        • Principal Investigator:
          • Ferdinand Formoso, MD
      • Miami Beach, Florida, United States, 33140
        • Recruiting
        • OSSO Health, Inc.
        • Contact:
          • Amir Mahajer, DO
        • Principal Investigator:
          • Amir Mahajer, DO
      • The Villages, Florida, United States, 32162
        • Recruiting
        • Interventional Pain Institute
        • Contact:
          • Brent Compton, MD, DC
        • Principal Investigator:
          • Brent Compton, MD, DC
      • Winter Park, Florida, United States, 32789
        • Recruiting
        • Conquest Research LLC
        • Principal Investigator:
          • Anand Patel, MD
        • Contact:
          • Anand Patel, MD
    • Georgia
      • Dunwoody, Georgia, United States, 30338
        • Recruiting
        • Emory Healthcare
        • Contact:
          • Oluseun Olufade, MD
        • Principal Investigator:
          • Oluseun Olufade, MD
      • Newnan, Georgia, United States, 30265
        • Recruiting
        • Vista Clinical Research
        • Principal Investigator:
          • Sandeep Vaid, MD
        • Contact:
          • Sandeep Vaid, MD
    • Hawaii
      • Kailua, Hawaii, United States, 96734
        • Recruiting
        • Hawaii Pain & Spine
        • Contact:
          • Jon Carlson, MD
        • Principal Investigator:
          • Jon Carlson, MD
    • Kansas
      • Kansas City, Kansas, United States, 66160
        • Recruiting
        • University of Kansas Medical Center
        • Contact:
          • Dawood Sayed, MD
        • Principal Investigator:
          • Dawood Sayed, MD
    • Kentucky
      • Edgewood, Kentucky, United States, 41017
        • Recruiting
        • Iqra Research
        • Contact:
          • Zeeshan Tayeb, MD
        • Principal Investigator:
          • Zeeshan Tayeb, MD
    • Louisiana
      • Slidell, Louisiana, United States, 70458
        • Recruiting
        • Paradigm Health System
        • Principal Investigator:
          • Thomas Myers, MD
        • Contact:
          • Thomas Myers, MD
    • Maryland
      • Annapolis, Maryland, United States, 21401
        • Recruiting
        • The Kahan Center
        • Contact:
          • Brian Kahan, DO
        • Principal Investigator:
          • Brian Kahan, DO
    • Nevada
      • Reno, Nevada, United States, 89511
        • Recruiting
        • Reno Tahoe Pain Associates
        • Principal Investigator:
          • Ali Nairizi, MD
        • Contact:
          • Ali Nairizi, MD
    • New York
      • Rochester, New York, United States, 14611
        • Recruiting
        • University of Rochester
        • Contact:
          • Ben LaPlante, DO
        • Principal Investigator:
          • Ben LaPlante, DO
    • North Carolina
      • Durham, North Carolina, United States, 27704
        • Recruiting
        • Eximia EquiHealth Research LLC/Emerge Ortho
        • Contact:
          • David B Musante, MD
        • Principal Investigator:
          • David B Musante, MD
      • Hendersonville, North Carolina, United States, 28792
        • Recruiting
        • AdventHealth Hendersonville
        • Contact:
          • William "Jeremy" Beckworth, MD
        • Principal Investigator:
          • William "Jeremy" Beckworth, MD
    • Ohio
      • Dayton, Ohio, United States, 45432
        • Recruiting
        • META Medical Research Institute, LLC
        • Principal Investigator:
          • Priyesh Mehta, DO
        • Contact:
          • Priyesh Mehta, DO
    • Oklahoma
      • Edmond, Oklahoma, United States, 73034
        • Recruiting
        • Clinical Investigations, LLC
        • Contact:
          • Douglas P Beall, MD
        • Principal Investigator:
          • Douglas P Beall, MD
    • Oregon
      • Portland, Oregon, United States, 97201
        • Recruiting
        • Axsendo Clinical Research/Compass Pain and Wellness
        • Contact:
          • Carl Balog, MD
        • Principal Investigator:
          • Carl Balog, MD
    • Pennsylvania
      • York, Pennsylvania, United States, 17402
        • Recruiting
        • OSS Health
        • Contact:
          • Michael B Furman, MD
        • Principal Investigator:
          • Michael B Furman, MD
    • Rhode Island
      • Providence, Rhode Island, United States, 02903
        • Recruiting
        • Rhode Island Hospital
        • Contact:
          • Alexios Carayannopoulos, DO, MPH
        • Principal Investigator:
          • Alexios Carayannopoulos, DO, MPH
    • South Carolina
      • Charleston, South Carolina, United States, 29406
        • Recruiting
        • Clinical Trials of South Carolina
        • Contact:
          • Edward M. Tavel Jr., MD
        • Principal Investigator:
          • Edward M. Tavel Jr., MD
    • Texas
      • Corpus Christi, Texas, United States, 78414
        • Recruiting
        • Institute of Precision Pain Medicine
        • Principal Investigator:
          • Mitchell Engle, MD, PhD
        • Contact:
          • Mitchell Engle, MD, PhD
      • Houston, Texas, United States, 77030
        • Recruiting
        • Paradigm Research Center/Houston Scoliosis and Spine Institute
        • Contact:
          • Ra'Kerry Rahman, MD
        • Principal Investigator:
          • Ra'Kerry Rahman, MD
      • Pearland, Texas, United States, 77584
        • Recruiting
        • Axsendo Clinical Research/Texas Institute of Pain and Spine
        • Contact:
          • Lance LaFleur, MD, MBA
        • Principal Investigator:
          • Lance LaFleur, MD, MBA
    • Virginia
      • Richmond, Virginia, United States, 23238
        • Recruiting
        • VA iSpine Physicians
        • Principal Investigator:
          • Michael J DePalma, MD
        • Contact:
          • Michael J DePalma, MD

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:

  • Participants with moderate to severe low back pain for a duration of at least six months who have failed at least 3 months of conservative care.
  • Participants who have moderate radiographic degeneration of an intervertebral disc from L1 to S1, with a single disc suspected of causing chronic lower back pain (CLBP).

Exclusion Criteria:

  • Participants who have been a recipient of prior allogeneic stem cell/progenitor cell therapy for any indication or autologous stem cell/progenitor cell therapy or other biological intervention to repair the index intervertebral disc.
  • Participants with low back pain duration of less than 6 months or greater than 60 months.
  • Participants who have not received at least 3 months of conservative treatment for back pain without adequate pain relief.
  • Participants taking systemic immunosuppressants.
  • Participants with osteoporosis.
  • Participants with alcohol or substance abuse problems.
  • Participants with severe depression or anxiety.
  • Participants with cauda equina syndrome; fibromyalgia, symptomatic central vertebral canal stenosis, lumbar spondylitis or other undifferentiated spondyloarthropathy affecting the index disc.
  • Participants having undergone a surgical procedure affecting the structure/biomechanics of the disc (e.g., discectomy, intradiscal electrothermal therapy, intradiscal radiofrequency, artificial disc replacement, interbody fusion, laminectomy, etc.) at the index or adjacent levels.
  • Participants who have received any lumbar intradiscal injection into the index disc or adjacent discs within three months prior to the start of screening, other than injection of contrast medium for discography.
  • Participants who received an epidural steroid injection within 6 weeks prior to informed consent.
  • Participants with evidence of neurologic deficit on any component of the lumbar neurological exam at baseline.
  • Participants with sacroiliac (SI) joint pain, as determined by a targeted physical exam, or SI joint injection.
  • Participants with facet joint pain, as determined by a medial branch block.
  • Participants with more than a single painful level.
  • Participants with a full thickness annular tear observed on magnetic resonance imaging (MRI) or discography.
  • Participants with low back pain that is less than moderate in severity.
  • Participants with extreme low back pain.
  • Participants who lack moderate to extreme functional limitations/disability.

Note: Other exclusion criteria may apply.

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: Rexlemestrocel-L + HA
Participants will receive rexlemestrocel-L 2.0 mL injection of approximately 6 million rexlemestrocel-L cells in freeze media mixed in a 1:1 by-volume ratio with hyaluronic acid (HA) solution on Day 0.
Rexlemestrocel-L will be combined in 1:1 by-volume ratio with HA solution and the resulting mixture will be administered as intradiscal injection.
Sham Comparator: Control Group
Participants will receive saline solution as a sham procedure to simulate the active treatment injection on Day 0.
Saline solution injection adjacent to the index disc.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Mean Change From Baseline in Daily Average Low Back Pain at 12 Months Post-treatment Based on Visual Analog Scale (VAS) Score
Time Frame: Baseline and Month 12
Low back pain intensity will be measured using a VAS ranging from 0-100 millimeter (mm). A score of 0 represents no pain and 100 represents worst possible pain.
Baseline and Month 12
Number of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs)
Time Frame: Up to Month 24
Up to Month 24

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Percentage of 30% VAS Pain Responders at 12 Months Post-treatment
Time Frame: Month 12
Responders are defined as participants who have at least a 30% decrease from baseline in daily average low back pain VAS score (measured as the average VAS score over 7 days). VAS score ranges from 0 (no pain) to 100 (worst possible pain).
Month 12
Mean Change From Baseline in Quality of Life Measured by Euroqol-5D (EQ-5D) Index Score at 12 Months Post-treatment
Time Frame: Baseline and Month 12
The EQ-5D is a generic instrument that consists of 5 dimensions: Mobility, selfcare, usual activities, pain/discomfort, and anxiety/depression, rated over five levels of severity ranging from no issues to extreme issues and the responses can be converted into a single number called an index score. The index scores are calculated ranging from 0 (worst quality of life) to 1 (perfect quality of life).
Baseline and Month 12
Percentage of Minimal Pain Responders at 12 Months Post-treatment
Time Frame: Month 12
Minimal pain responders are defined as participants who have a low back pain daily average VAS score (measured as the average VAS score over 7 days) of 20 mm or less. VAS score ranges from 0 (no pain) to 100 (worst possible pain).
Month 12
Mean Change From Baseline in Function as Measured by Oswestry Disability Index (ODI) Questionnaire Score at 12 Months Post-treatment
Time Frame: Baseline and Month 12
ODI scores ten aspects of the participant's home and work life and analgesic use in a range of 0 (least amount of disability) to 5 (severe disability). The disability index is then calculated by summing the scores for all questions answered, then multiplied by two and reported in a 0 to 100% range where higher numbers indicate a higher level of disability.
Baseline and Month 12
Percentage of Participants With 30% VAS and 10-point ODI Treatment Success at 12 Months Post-treatment
Time Frame: Month 12
Treatment success based on the percentage of participants who have at least a 30% reduction from baseline in daily average low back pain VAS score (measured as the average VAS score over 7 days) with at least a 10-point decrease from baseline ODI score will be reported.
Month 12
Percentage of Participants Who Ceased Opioid Usage at 24 Months Post-treatment
Time Frame: Month 24
Month 24

Collaborators and Investigators

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

Sponsor

Investigators

  • Study Director: Roger D Brown, Mesoblast, Ltd.

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)

July 3, 2024

Primary Completion (Estimated)

October 1, 2026

Study Completion (Estimated)

October 1, 2027

Study Registration Dates

First Submitted

March 15, 2024

First Submitted That Met QC Criteria

March 15, 2024

First Posted (Actual)

March 22, 2024

Study Record Updates

Last Update Posted (Actual)

January 27, 2026

Last Update Submitted That Met QC Criteria

January 23, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

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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