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RecruitingNCT07100782Updated Feb 18, 2026

Estradiol-mediated Inflammation and Central Sensitization in the Pathophysiology of Endometriosis-associated Pelvic Pain

A Phase 3 interventional study of Relugolix CT in Endometriosis and Pelvic Pain, sponsored by University of Michigan. Recruiting at 1 site in United States. Open to female participants aged 18 Years to 49 Years. Per ClinicalTrials.gov, last updated 2026-02-18.

Sponsored by University of Michigan · Phase 3, Interventional, and Treatment

From the registry’s dates

  • Started Dec 2025; still recruiting 9 months later.
Phase
Phase 3
Study type
Interventional
Enrollment
130
Allocation
Not applicable
Ages
18 Years to 49 Years
Sex
Female
01

Study summary

The purpose of this study is to better understand how hormone suppression with Relugolix Combination-Therapy (CT) affects pelvic pain, inflammation, and pain sensitivity in women with moderate-to-severe endometriosis associated pelvic pain.

Read the detailed description

All clinical activities will be performed at University of Michigan (note that recruitment may occur at locations outside of University of Michigan, such as Trinity Health, Ann Arbor, MI and Henry Ford, Detroit, MI and via social media and regional patient support groups). Endometrial biopsies will be sent via overnight courier to Dr. Jie Yu's laboratory at The University of Buffalo for analysis.

02

Conditions studied

  • Endometriosis
  • Pelvic Pain

Keywords

  • Relugolix Combination Therapy
  • Endo-EPIC (Alternative study acronym/title)
03

In context

Endometriosis

901 studies on the registry are indexed under Endometriosis; 259 are open to participants now.

This study's planned enrollment of 130 is above the median of 64 across 525 interventional studies indexed under Endometriosis.

Browse Endometriosis studies →

Lead sponsor

University of Michigan is the lead sponsor of 1,475 studies on the registry; 196 are open to participants now.

Of its 162 completed or terminated interventional studies of FDA-regulated products, 128 (79%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 49 Years
Sexes eligible
Female
Accepts healthy volunteers
No

Inclusion criteria

  • Premenopausal woman between age 18 and 49 years (inclusive) at the time of consent. Menopause is defined as amenorrhea >1 year unrelated to hormonal suppression.
  • History of endometriosis diagnosed by surgery (visual or biopsy confirmed), ultrasound, or MRI within 10 years of study entry
  • History of self-reported moderate to severe pelvic pain for ≥ 6 months' duration at time of screening visit.
  • Willingness to participate in a relugolix CT drug intervention trial
  • Has not used an injectable hormone therapy in the past 6 months (e.g. DepoProvera®, DepoLupron®).
  • Willingness to 30-60 day washout interval of oral, vaginal, transdermal, intrauterine hormonal therapies prior to study initiation if applicable
  • Willingness to use 2 forms of non-hormonal contraception during the entire duration of the study period or has had a history of a bilateral tubal occlusion procedure at least 3 months prior to screening (tubal ligation or hysteroscopic occlusion method)
  • Willing to undergo quantitative sensory testing (QST), fMRI and other study procedures
  • Ability to read and speak English to allow for written informed consent, phenotyping, and patient-reported outcomes measures
  • Meet criteria to participate in QST and fMRI. These include:
  • Normal visual acuity or correctable (with corrective lenses- glasses or contacts) to at least 20/40 for reading instructions in the MRI and visual sensitivity testing
  • No contraindications to MRI (e.g., metal implants, claustrophobia)
  • Willingness to refrain from pain medications such as NSAIDs, acetaminophen, and opioids for 12 hours prior to neuroimaging and QST
  • Willingness to refrain from alcohol and nicotine on day of QST and neuroimaging (alcohol and nicotine consumption is allowed after testing is completed)
  • Willingness to refrain from physical activity or exercise that would cause muscle and/or joint soreness for 48 hours prior to testing (routine exercise or activity that does not lead to soreness is acceptable)
  • Able to lie still on their back for 1 hour during MRI
  • Weigh 300 pounds or less.

Additional inclusion criteria to proceed with Study Visit 2 and clinical trial:

  • >60% complete entries in daily electronic diary (end-of-day pain, bleeding, fatigue scores)
  • Minimum of two menstrual flows separated by a minimum of 21 days (d1 bleed to next d1 bleed) during the washout/screening period
  • Moderate-severe non-menstrual pain and dysmenorrhea confirmed with daily electronic diary in the washout/screening period.

Exclusion criteria

Exclusion Criteria:

  • Contraindication to the use of relugolix CT (high risk of arterial or venous thrombotic, or thromboembolic disorder, known osteoporosis, current or history of breast cancer or other hormone sensitive malignancy, known hepatic impairment or disease, undiagnosed abnormal uterine bleeding, known hypersensitivity to components of relugolix CT).
  • Concurrent participation in other therapeutic trials
  • Pregnant, lactating, less than 6 months postpartum, or planning a pregnancy within next 12 months
  • Planning pelvic or abdominal surgery during study period
  • Prior major surgery in the past 4 months that involves incisions on the abdomen, chest, head, other than a skin biopsy (hysteroscopy, endometrial biopsy is ok to include).
  • Planning to initiate a new adjunctive pain treatment during study treatment (e.g. cognitive behavioral therapy, physical therapy, acupuncture). Participants may be enrolled if these treatments are completed prior to trial or using stable therapies.
  • History of hysterectomy and/or bilateral oophorectomy
  • Clinically significant gynecologic condition such as significant endometrial pathology (e.g. endometrial hyperplasia), persistent ovarian cyst larger than 5 cm, largest uterine dimension >15 centimeters and not planning an additional intervention or treatment for endometriosis, or another uterine or ovarian condition during the study period. Patients may be enrolled in this study if they were previously successfully treated for these conditions. Patients must have undergone pelvic ultrasound or MRI in the past 6 months, and provide results (or release of records to obtain results)
  • History or current evidence of psychosis, current suicide risk or attempt within 2 years of study (note: participants with mood disorders such as depression or anxiety will not be excluded)
  • Chronic opioid, alcohol, and/or illicit drug use
  • History of substance abuse within past one year
  • Unable or unwilling to discontinue opioids analgesics within 48 hours of the dense phenotyping study visits
  • Medical conditions that may significantly interfere with relugolix CT efficacy, ability to fully comply or would make it unsafe for participants to take part in the study, including but not limited to: morbid obesity with Body Mass Index > 45, uncontrolled autoimmune/inflammatory diseases, significant cardiopulmonary disease (e.g., angina, congestive heart failure, uncontrolled hypertension, severe cardiac valvular disease, Chronic Obstructive Pulmonary Disease (COPD), chronic asthma), renal or liver disease (e.g. cirrhosis, hepatitis), uncontrolled endocrine or allergic disorders (e.g., hypothyroidism, diabetes, allergic rhinitis), neurologic conditions (e.g., multiple sclerosis, prior stroke, neurological tumor), severe physical impairment (e.g., blindness, deafness, paraplegia); and active malignancy (any malignancy except for localized dermatologic cancer).
  • Any impairment, activity or situation that in the judgment of the Study Coordinator or Principal Investigator would prevent safe or satisfactory completion of the study protocol.
  • Individuals receiving or applying for compensation or disability and other aspects associated with potential secondary gain per self-report;
  • Additional exclusion that prevent participation in QST and fMRI:

    1. Severe claustrophobia precluding MRI and evoked pain testing during scanning;
    2. Diagnosed peripheral neuropathy
    3. Diagnosed epilepsy
    4. Diagnosed or self-reported visual-evoked migraines can participate in study, but will not participate in the visual testing procedures.
    5. Weigh >300 pounds
05

Study design

Phase
Phase 3
Primary purpose
Treatment
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrollment
130 participants (estimated)

Study arms

  • Experimental
    Relugolix CT

    All participants will have the same intervention, but approximately half of those enrolled will have widespread pain and half will not. Approximately 65 participants with widespread pain will receive relugolix CT (relugolix 40mg, estradiol 1 mg, norethindrone acetate 0.5 mg once daily) daily for 24 weeks, and 65 participants without widespread pain will receive relugolix CT for 24 weeks.

    Drug: Relugolix CT

Interventions

  • DrugRelugolix CT

    Study medication will be provided by Sumitomo in pill bottles containing an 84-day supply of relugolix 40mg, estradiol 1mg, norethindrone acetate 0.5mg (Relugolix Combination therapy).

    Also known as: Myfembree

06

What researchers measure

Primary outcomes

  1. Change score in lipopolysaccharide (LPS)-stimulated Macrophage inflammatory protein-1 alpha (MIP1-α) levels

    LPS-stimulated MIP1-α levels measured from whole blood

    Time frame: baseline and week 12 visit

  2. Change score for functional magnetic resonance imaging (fMRI) connectivity of the somatosensory cortices to the default-mode network

    Assessed using a functional connectivity MRI (fcMRI) at rest and applied pain

    Time frame: baseline and week 12 visit

Secondary outcomes

  1. Change scores for pelvic pain interference

    Pain interference assessed using the Patient-Reported Outcomes Measurement Information System (PROMIS) 29+2 Profile v2.1 pain interference domain. Each domain ranges in score from 4-20 and the higher the score indicates greater pain interference in the past 7 days.

    Time frame: baseline and week 12 visit

  2. Change score for temporal summation at the forearm

    Temporal summation is calculated as the mean difference in pain ratings evoked by the single stimuli and the trains of stimuli using a 0-100 NRS.

    Time frame: baseline and week 12 visit

07

Study locations

1 of 1 sites recruiting
  • University of Michigan
    Ann Arbor, Michigan 48109, United States
    • Kathy Scott · Contact · jrsj@med.umich.edu · 734-998-7022
    • Sawsan As-Sanie, MD, MPH · Principal investigator
    Recruiting
08

References and documents

Individual participant data

Plan to share: Yes — De-identified datasets including participant self-report data will be uploaded into a NIH compliant data repository (NIMH Data Archive and National Institute of Child Health and Human Development (NICHD) DASH)

Supporting information: Study protocol, Icf

No publications or documents are linked to this record.

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Feb 18, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT07100782
Lead sponsor
University of Michigan
Collaborators
Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
Responsible party
Sawsan As-Sanie (Professor of Obstetrics and Gynecology, University of Michigan) — Principal investigator
First posted
Aug 3, 2025
Start date
Dec 8, 2025
Primary completion
Aug 2028 (estimated)
Completion
Sep 2028 (estimated)
Last update
Feb 18, 2026

Study contacts

Kathy Scott
Contact
jrsj@med.umich.edu
734-998-7022
Sawsan As-Sanie, MD, MPH
principal investigator · University of Michigan
Andrew Schrepf, PhD
principal investigator · University of Michigan

Oversight

FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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