Insights in Endocervical Mucus Secretion

Single arm interventional study looking at biological outcomes at 4 time points throughout the cycle before and after taking an oral gonadotropin-releasing hormone antagonist (gnRH). Samples of whole blood, endocervical mucus, endocervical biopsy, and vaginal swab will be collected.

Study Overview

• Status: Recruiting
• Conditions: Cervical Mucus
• Intervention / Treatment: Drug: Gonadotropin Releasing Hormone Antagonists Relugolix

Detailed Description

This study will enroll participants and obtain biological samples at 4 time points. The study will begin on the first day of menstruation following enrollment. Patients will monitor for peri-ovulation using an ovulation test that monitors for urinary metabolites for luteinizing hormone (LH). At the midluteal time point for sampling (days 6-9 after "high fertility" on ovulation test) subjects will begin taking an oral gonadotropin-releasing hormone antagonist (gnRH) (relugolix) for 10 days. Samples of whole blood, endocervical mucus, endocervical biopsy, and vaginal swab will be collected during the early follicular phase (3-5 days following the start of menstruation), peri-ovulation (9-14 days following the start of menstruation based on estriol glucuronide (E3G) urinary metabolite), mid-luteal (6-9 days following mid-cycle draw), and upon stoppage of relugolix (9-11 days following relugolix initiation).

• Study Type: Interventional
• Enrollment (Estimated): 15
• Phase: Phase 4

Contacts and Locations

• Study Contact: Name: Women's Health Research Unit Recruitment Line; Phone Number: 503-494-3666; Email: whru@ohsu.edu

Study Locations

• United States
  • Oregon
    • Portland, Oregon, United States, 97239
      • Recruiting
      • Oregon Health & Science University
      • Contact: Leo Han, MD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Normal menstrual cycles of 25-35 days in length for at least the previous 3 cycles
• BMI >18 and <35
• Serum p4 >= 3 ng/ml on single sample collected between days 18-25 of self-reported menstrual cycle
• Flexible schedule allowing blood draws on less than 48 hour notice
• In good general health
• Commit to using non-hormonal contraceptive methods without spermicide during study period except those prescribed in the experimental protocol
• No objections to taking study drugs
• No objections to refraining from intercourse the night before any sampling and willing to use condoms during vaginal intercourse

Exclusion Criteria:

• Oral contraceptive use or other hormone supplement within the preceding 2 months
• Current cervical infection
• Evidence of abnormal cervical cytology
• Use of any IUD for contraception
• Long-acting hormonal contraceptive use in the past 12 months (e.g., Depo-Provera)
• Contraindications to study drugs
• Current or past pregnancy within the previous 6 months or currently trying to conceive
• Desiring to conceive in the next 8 months
• Breastfeeding in the past 2 months
• Diagnosed diabetes or metabolic syndrome
• Diagnosed Polycystic Ovary Syndrome
• History of, or self-reported, substance abuse
• Smoker
• Previous infertility treatment excluding male factor issues
• Use of an investigational drug within the past 2 months
• History of excisional or ablative treatment procedure on cervix (i.e., LEEP, Cryotherapy, Cold Knife Cone)
• Current treatment for a vaginal infection such as bacterial vaginosis
• History of venous thromboembolism (VTE) or inherited thrombophilias

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Relugolix; Participants will take Reugolix for 10 days starting at the midluteal time point (6-9 days after "high fertility" based on ovulation test)	Drug: Gonadotropin Releasing Hormone Antagonists Relugolix; Gonadotropin releasing hormone antagonist (gnRH) taken for 10 days starting during the midluteal phase.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cervical mucus scores	Average cervical mucus scores at each study time point	Cervical mucus will be collected and compared across 4 time points during the menstrual cycle (follicular [3-5 days following start of menses], ovulatory, luteal, ovarian suppression [9-11 days following Relugolix initiation])
Single cell transcriptome analysis	Single cell transcriptome analysis comparing changes across menstrual time points	Measured and compared across 4 time points during the menstrual cycle (follicular [3-5 days following start of menses], ovulatory, luteal, ovarian suppression [9-11 days following Relugolix initiation])
Proteomic analysis	Proteomic analysis of mucus including Mucin concentration	Measured and compared across 4 time points during the menstrual cycle (follicular [3-5 days following start of menses], ovulatory, luteal, ovarian suppression [9-11 days following Relugolix initiation])

Collaborators and Investigators

• Sponsor: Oregon Health and Science University
• Collaborators: Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD); National Institutes of Health (NIH)
• Investigators: Principal Investigator: Leo Han, MD, Oregon Health and Science University

Study record dates

Study Major Dates

• Study Start (Actual): January 2, 2026
• Primary Completion (Estimated): August 1, 2027
• Study Completion (Estimated): August 1, 2027

Study Registration Dates

• First Submitted: July 28, 2025
• First Submitted That Met QC Criteria: August 6, 2025
• First Posted (Actual): August 8, 2025

Study Record Updates

• Last Update Posted (Actual): January 8, 2026
• Last Update Submitted That Met QC Criteria: January 6, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Hormones, Hormone Substitutes, and Hormone Antagonists; Androgen Antagonists; relugolix
• Other Study ID Numbers: STUDY00028821; R01HD115770-01A1 (U.S. NIH Grant/Contract)

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