MYFEMBREE®: A Retrospective Cohort Study Using an Administrative Healthcare Database to Assess Pregnancy Outcomes in Women Treated With Relugolix Combination Therapy

This is a retrospective cohort study that will be conducted using secondary de-identified electronic healthcare data (EHD) that originally were collected for the purposes of health insurance billing and/or routine patient care from healthcare providers (HCPs). The study is designed to evaluate the association between relugolix combination therapy (relugolix 40 mg, estradiol 1 mg, and norethindrone acetate 0.5 mg) exposure during pregnancy and subsequent fetal and infant outcomes.

Study Overview

• Status: Active, not recruiting
• Conditions: Pregnancy Complications; Pregnancy Related; Pregnancy, High Risk
• Intervention / Treatment: Drug: Relugolix + Estradiol + Norethindrone Acetate

Detailed Description

The study will identify pregnant women exposed to relugolix combination therapy during pregnancy from a United States (US) administrative claims database. The primary outcome measure is major congenital malformations (MCMs) among linked live births. Secondary outcome measures include spontaneous abortion (SAB), stillbirth, small size for gestational age (SGA), and preterm birth. Infants of pregnancies with linked live birth outcomes will be followed up to 12 months of age for identification of MCMs. Anticipated enrollment is 530 live births.

• Study Type: Observational
• Enrollment (Estimated): 530

Contacts and Locations

Study Locations

• United States
  • Massachusetts
    • Marlborough, Massachusetts, United States, 01752
      • SMPA

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 50 years (Adult)
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

The study population will include 2 cohorts: The exposed cohort will include pregnant women with conditions for which relugolix combination therapy is prescribed and who are exposed to relugolix combination therapy at any time during pregnancy. The unexposed cohort will include pregnant women with conditions for which relugolix combination therapy could be prescribed and who are not exposed to relugolix combination therapy at any time during pregnancy.

Description

Inclusion Criteria:

• Woman ≥ 18 and ≤ 50 years of age at time of conception
• Diagnosis of a condition for which relugolix combination therapy is prescribed (diagnosis captured at any time prior to the estimated date of conception)

Cohort 1

• Exposure to relugolix combination therapy at any time during pregnancy

Cohort 2

• No exposure to relugolix combination therapy at any time after the estimated date of conception (during pregnancy)

Exclusion Criteria:

• Exposure to known teratogens during pregnancy
• < 6 months of continuous healthcare coverage immediately prior to date of conception

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Exposed Cohort; Pregnant women with conditions for which relugolix combination therapy is prescribed, who are exposed to relugolix combination therapy at any time during pregnancy	Drug: Relugolix + Estradiol + Norethindrone Acetate; Relugolix combination therapy (relugolix 40 mg; estradiol 1 mg; norethindrone 0.5 mg); Other Names: MVT-601; MVT-601A; MYFEMBREE
Unexposed Cohort; Pregnant women with conditions for which relugolix combination therapy could be prescribed, who are not exposed to relugolix combination therapy at any time during pregnancy

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Major Congenital Malformation (MCM)	Comparison of rate of MCM between cohorts	Up to 5 years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Spontaneous abortion (SAB)	Comparison of rate of SABs between cohorts	Up to 5 years
Stillbirth	Comparison of rate of stillbirths between cohorts	Up to 5 years
Preterm birth	Comparison of rate of preterm births between cohorts	Up to 5 years
Small for gestational age (SGA)	Comparison of rate of SGA between cohorts	Up to 5 years

Collaborators and Investigators

• Sponsor: Sumitomo Pharma Switzerland GmbH

Study record dates

Study Major Dates

• Study Start (Actual): April 30, 2025
• Primary Completion (Estimated): May 1, 2027
• Study Completion (Estimated): May 1, 2027

Study Registration Dates

• First Submitted: February 13, 2023
• First Submitted That Met QC Criteria: February 13, 2023
• First Posted (Actual): February 22, 2023

Study Record Updates

• Last Update Posted (Actual): August 1, 2025
• Last Update Submitted That Met QC Criteria: July 30, 2025
• Last Verified: July 1, 2025

More Information

Terms related to this study

• Keywords: Pregnancy; Endometriosis; Uterine Fibroids; Relugolix
• Additional Relevant MeSH Terms: Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Pregnancy Complications; Contraceptive Agents, Hormonal; Physiological Effects of Drugs; Hormones; Hormones, Hormone Substitutes, and Hormone Antagonists; Reproductive Control Agents; Hormone Antagonists; Contraceptive Agents, Female; Contraceptive Agents; Androgen Antagonists; Estrogens; Contraceptives, Oral; Contraceptives, Oral, Hormonal; Contraceptives, Oral, Synthetic; Norethindrone Acetate; Relugolix; Estradiol; Norethindrone
• Other Study ID Numbers: MVT-601A-003

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.: Yes