Phase 3
Completed N=1,164
Study of the Safety and Contraceptive Efficacy of Relugolix Combination Therapy in Women With Uterine Fibroids or Endometriosis Who Are at Risk for Pregnancy
Source: ClinicalTrials.gov NCT04756037 ↗Enrolled (actual)
1,164
Serious AEs
2.0%
Results posted
May 2026
Primary outcomePrimary: Contraceptive Efficacy of Relugolix Combination Therapy as Assessed by the At-Risk Pearl Index (PI) — 1.27 Pregnancies per 100 woman-years
◆ Published Evidence
Emerging
11citations · ~4 / year
Oral Gonadotropin-Releasing Hormone Antagonists for the Treatment of Uterine Leiomyomas.
Summary
The purpose of this study is to assess the contraceptive efficacy of relugolix combination therapy.
Linked Publications
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Oral Gonadotropin-Releasing Hormone Antagonists for the Treatment of Uterine Leiomyomas.
Outcome Measures
| Outcome | Result | p-value |
|---|---|---|
| PRIMARY Contraceptive Efficacy of Relugolix Combination Therapy as Assessed by the At-Risk Pearl Index (PI) |
1.27 | — |
| SECONDARY Contraceptive Efficacy of Relugolix Combination Therapy as Assessed by the Modified At-Risk PI |
1.10 | — |
| SECONDARY Contraceptive Efficacy of Relugolix Combination Therapy as Assessed by the Gross PI |
1.04 | — |
| SECONDARY Contraceptive Efficacy of Relugolix Combination Therapy as Assessed by the Method Failure PI |
0.64 | — |
| SECONDARY Contraceptive Efficacy of Relugolix Combination Therapy as Assessed by the Cumulative 1-Year Pregnancy Rates |
1.2 | — |
| SECONDARY Number of Participants Who Do Not Complete 13 Treatment Cycles |
667 | — |
| SECONDARY Percent Change in Bone Mineral Density From Baseline to 6 and 12 Months On-Treatment |
-0.65; -0.72; -0.36; -0.47; -0.36; -0.56 | — |
Eligibility Criteria
Key Inclusion Criteria
- Is a premenopausal woman, 18 to 50 years of age.
- Is at risk of pregnancy (that is, having heterosexual intercourse at least once per month) and is seeking contraception.
- Has normal, regular menstrual cycles that are between 21 and 35 days in duration.
- Has a diagnosis of uterine fibroids or endometriosis meeting either of the following criteria:
- Diagnosis of uterine fibroids by confirmation of ultrasound performed in the last 2 years and patient report of heavy menstrual bleeding affecting quality of life.
- Diagnosis of endometriosis and has had surgical or direct visualization (laparoscopy or laparotomy) and/or histopathologic confirmation of endometriosis, and the patient reports moderate, severe, or very severe pain during the most recent menses and/or during nonmenstrual portion of the cycle in the prior month
- Is willing to use the study intervention as the sole method of contraception for 13 consecutive 28-day treatment cycles and does not intend to use any other form of contraception (for example, condoms).
Key Exclusion Criteria
- Is pregnant, or breastfeeding, or has breastfed in the last year.
- Has a known history of infertility or sub-fertility.
- Has presence or history of a venous thromboembolic event (for example, deep vein thrombosis, pulmonary embolism), an arterial thrombotic or thromboembolic event (for example, myocardial infarction, stroke, or peripheral arterial), or a transient ischemic attack, angina pectoris, or claudication.
- Has a higher risk of arterial, venous thrombotic, or thromboembolic disorders.
- Has a history of migraine with aura or focal neurological symptoms.
- Has uncontrolled hypertension, diabetes with inadequate control, or multiple cardiovascular risk factors.
- Has a history of clinically significant ventricular arrhythmias.
- Has clinically significant liver disease, including active viral hepatitis or cirrhosis.
- Has a history of pancreatitis associated with severe hypertriglyceridemia.
- Has known human immunodeficiency virus (HIV) infection or high risk of contracting HIV.
- Has a hepatic hemangioma or has a history of cholestasis with prior estrogen use or during pregnancy.
- Has a serious contraindication to pregnancy (for example, a medical condition or use of chronic medication such as isotretinoin or thalidomide).
- History of suicidal ideation or behavior, or confirmed "yes" to any question (with exception of non-suicidal self-injurious behavior, unless deemed as an unacceptable risk by the investigator) on the C-SSRS.
- Has a bone mineral density Z-score ≤ -2.0 at lumbar spine, femoral neck, or total hip during the screening period.
- Has a history of or currently has osteoporosis, or other metabolic bone disease, collagen vascular disease, chronic kidney disease (CKD) stage 3 or greater with glomerular filtration rate (GFR) < 60 mL/min/m2 using Modification of Diet in Renal Disease (MDRD) method, hyperparathyroidism, hyperprolactinemia, known pituitary adenoma, hyperthyroidism, anorexia nervosa, abnormal bone mineral metabolism (eg, hypophosphatemia), or low traumatic (fragility) fracture.
- Has used chronic glucocorticoids that are oral, parenteral, inhaled (prednisone equivalents of ≥ 2.5 mg daily for ≥ 3 months) in 12 months prior to the study.
- Has known BRCA mutation or other mutation associated with increased risk of breast cancer.
Data sourced from ClinicalTrials.gov (NCT04756037) and the linked publication. Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication. Informational only — not medical advice.