M640 for Acute Low Back and Leg Pain

This study is looking at whether a modified version of metaxalone 640 mg, a medication for muscle discomfort, can help reduce acute (newly occurring) low back and leg pain. You might be able to join if you are between 18 and 80 years old, have new back or leg pain, and your pain level is 6 or higher on a Numeric Pain Scale. The study will compare metaxalone 640 mg to a look-alike substance without active medicine. Success will be measured by changes in your pain from Day 1 to Day 7. The current recruitment status is unclear.

Study design
This is a double-blind, randomized, placebo-controlled study, meaning neither you nor your doctor will know if you are receiving the active drug or a placebo (inactive substance). About 50 participants are planned for this initial study.
What's involved
You will answer questions about your pain, physical activity, and sleep on Day 1 before treatment, and again 7 days after treatment.
Compensation
Not stated in the trial record.
Follow-up
Your pain will be measured from Day 1 to Day 7 after treatment.

AI-generated from the public study record. Only the study team can confirm whether you're eligible — confirm details with them before making decisions.

NCT06157177

Efficacy of M640 in Acute Lumbosacral Musculoskeletal Conditions.

Recruiting
PHASE4Ages 18–80InterventionalTreatment
Primus Pharmaceuticals
~50 participants
Updated 2026-05-12 on ClinicalTrials.gov
What's tested:Metaxalone 640 mg Oral Tablet

At a glance

Recruiting sites
8 of 24 listed sites are recruiting right now
RecruitingSuspended, closed, or not yet open
What they're measuring
Change of Numeric Pain Scale
Measured over Day 1 to Day 7
Sciatica Acute
Lumbar Spinal Stenosis
24 sites across 11 states
Florida11
Texas4
Alabama1
California1
Georgia1
Michigan1
New Mexico1
North Carolina1
  • S Sodhi · STUDY_DIRECTOR · Illumination Health

Opens a ready-to-send draft in your own email app — review before sending.

Do you actually qualify for this trial?

Add a private profile and we'll compare every criterion below against your situation — and tell you which ones are met, uncertain, or excluding.

Check eligibility for this trial ~2 min · HIPAA-protected · delete anytime
Eligibility criteria

Inclusion

No clinically significant conditions impacting quality or quantity of pain
Baseline Numeric Pain Scale ≥ 6
Capable of answering text or email survey reminders
Low back pain with or without sciatica

Exclusion

Current use of other skeletal relaxants
Current use of other pain relievers
Current use of cimetidine or monoamine oxidase inhibitors
  • Change of Numeric Pain ScaleDay 1 to Day 7

    Change from Baseline in low back pain and leg pain as measured by the Numeric Pain Rating Scale (NPRS) at Day 7