A Study of Retatrutide (LY3437943) in Participants Who Have Obesity or Overweight and Chronic Low Back Pain

What Was Tested

In this phase 3 trial, researchers set out to test Retatrutide for chronic pain: fibromyalgia & crps.

Participation in the study will last about 80 weeks.

It had two arms (groups): Retatrutide (experimental) and Placebo (placebo comparator).

Participants will receive Retatrutide subcutaneously (SC).

Participants will receive Placebo SC.

The registry classes the interventions as drug.

Who Took Part

586 planned participants were the target.

It was open to people of any sex aged from 18 years with no upper age limit.

Healthy volunteers were not accepted; participants needed the condition being studied.

Examples of who could join: Have a history of axial-predominant low back pain. Have pain that is restricted to the low back or with a referral pattern limited to the proximal legs. Have a body mass index (BMI) ≥27 kilograms per square meter (kg/m2) at screening. Have a history of at least 1 self-reported unsuccessful dietary effort to lose body weight.

The full record lists 4 inclusion and 7 exclusion criteria; among the exclusions: have a non-axial origin low back pain; have had botulinum or steroid injections to the spine within 1 year of screening; have had trigger point injection to the spine within 6 months of screening.

How the Study Was Run

Design: randomized, parallel-group and double-blind.

Because people in this Retatrutide study were split into groups at random, differences between the groups are less likely to reflect who happened to join each one.

Groups ran in parallel: each of the chronic pain: fibromyalgia & crps participants stayed in one arm throughout.

As a double-blind Retatrutide study, the assignments were hidden from both participants and investigators until the end.

Those kept unaware of assignments: participant and investigator.

It started in 2025-05-29 with completion listed for 2027-09.

It ran at 40 sites in United States (25), Argentina (9), Canada (5) and Poland (1).

Its stated primary purpose is treatment.

What Was Measured

The main thing measured (primary outcome): Change from Baseline in Pain Intensity Per Numeric Rating Scale (time frame: Baseline, up to 72 weeks). Percent Change from Baseline in Body Weight (time frame: Baseline, up to 72 weeks).

It also tracked 12 secondary outcomes, for example Change in Physical Function as Measured by Patient-Reported Outcomes Measurement Information Systems (PROMIS), Change in Pain Interference as Measured by PROMIS, Change in Sleep as Measured by PROMIS, Change in Patient Reported Health Outcomes as Measured by Medical Outcomes Study 36-item Short Form Health Survey version 2 (SF-36v2), Change in Waist Circumference and Change in Biomarkers of Inflammation as Measured by Blood Test.

What This Means in Plain Language

Put simply, this is a phase 3, randomized trial of Retatrutide in 586 people with chronic pain: fibromyalgia & crps.

With 586 participants it is a large trial for this field.

Its status is active not recruiting; no results are posted to the registry yet, so nothing here describes outcomes.

More context: the Retatrutide compound page, Chronic pain: fibromyalgia & CRPS research.