A Phase 3 interventional study of Elagolix 200 MG and Placebo or SOC IVF in Infertility and Endometriosis, sponsored by Yale University. Completed at 5 sites in United States. Open to female participants aged 18 Years to 40 Years. Per ClinicalTrials.gov, last updated 2026-06-12.
Sponsored by Yale University · Phase 3, Interventional, and Treatment
A Phase 3 clinical trial of oral GnRH antagonist pre-treatment for women with endometriosis who are undergoing IVF, with a primary outcome of live birth rate. The investigators' central hypothesis is that in infertile woman with endometriosis undergoing in vitro fertilization-embryo transfer (IVF-ET), live birth rates will improve in those pretreated with GnRH antagonist compared to those not pretreated with GnRH antagonist.
Infertility is a common complication of endometriosis; while IVF successfully treats endometriosis-associated infertility, pregnancy rates are diminished compared to other etiologies of infertility. The study's long- term objectives are to better identify and treat endometriosis related infertility. The investigators' central hypothesis is that in infertile woman with endometriosis undergoing in vitro fertilization-embryo transfer (IVF-ET), live birth rates will improve in those pretreated with GnRH antagonist compared to those not pretreated with GnRH antagonist. The use of gonadotropin releasing hormone (GnRH) agonist prior to IVF has been suggested to improve success, however studies have been small and rarely reported live birth rates. Further, use of this approach is limited by the long treatment time required. Recent approval of an oral GnRH antagonist for endometriosis provides a novel option for women with endometriosis who are undergoing IVF. This agent avoids parenteral administration and the prolonged delay in initiation of action as was seen with GnRH agonists. There have been no studies on the efficacy of GnRH antagonists for the treatment of endometriosis-related infertility. The investigators propose a clinical trial of oral GnRH antagonist pre-treatment for women with endometriosis who are undergoing IVF, with a primary outcome of live birth rate. Participants will include those who agree to be randomized and those who do not want to be randomized. Those who agree to be randomized will be randomly assigned to either the elagolix group or placebo group. Those who do not want to be randomized can choose either the active treatment elagolix and follow the same procedures as those agreeing to be randomized or continue their ongoing or planned IVF and follow standard of care (SOC) (SOC IVF) if they do not want to delay the IVF procedure.
2,506 studies on the registry are indexed under Infertility; 407 are open to participants now.
This study's enrollment of 103 is below the median of 120 across 1,698 interventional studies indexed under Infertility.
Browse Infertility studies →Yale University is the lead sponsor of 1,724 studies on the registry; 298 are open to participants now.
Of its 210 completed or terminated interventional studies of FDA-regulated products, 126 (60%) have results posted.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
Patients with cirrhosis or abnormal LFTs per self report or documented in the electronic medical record (EMR).
For those who agree to be randomized, subjects will be randomized to elagolix 200mg BID. The medication will be taken orally and subjects will be counseled to take the medication at the same time each day. This arm will also include participants who do not want to be randomized while choose elagolix.
Drug: Elagolix 200 MG
For those who agree to be randomized, subjects will be randomized to placebo, BID. The medication will be taken orally and subjects will be counseled to take the medication at the same time each day. This arm will also include participants who want to continue their ongoing or planned IVF and follow standard of care (SOC) (SOC IVF) if they do not want to delay the IVF procedure.
Other: Placebo or SOC IVF
Elagolix tablet
Also known as: Orlissa
Sugar pill manufactured to mimic Elagolix 200mg
Live Birth Rate
The percentage of the number of participants with a live birth at ≥24 weeks of gestation out of those who were enrolled in the study
Time frame: Up to 15 months
Fertilization Rate
The percentage of the total number of fertilized oocytes (two pronuclei) out of the total number of injected/inseminated oocytes across all participants in each Arm/Group who had the current or previous IVF data
Time frame: Up to 9 months
Number of Embryos Transferred
Number of embryos transferred per participant
Time frame: Up to 9 months
Implantation Rate
The percentage of the total number of gestation sacs visible by Ultrasound out of the total number of transferred embryos across all participants in each Arm/Group who completed embryo transfer
Time frame: Up to 9 months
Biochemical Pregnancy Rate
The percentage of the number of participants with positive pregnancy tests following embryo transfer out of those who were enrolled in the study
Time frame: Up to 9 months
Clinical Pregnancy Rate
The percentage of the number of participants with ultrasound evidence of intrauterine gestational sac with fetal cardiac activity out of those who were enrolled in the study
Time frame: Up to 10 months
Miscarriage Rate
Percentage of the number of participants with a pregnancy loss out of those who have achieved pregnancy
Time frame: Up to 10 months
Overall Pregnancy Complication Rate
Percentage of the number of participants who had the overall pregnancy complication out of those who have achieved pregnancy. Overall pregnancy complication including any of the following: preterm delivery, preeclampsia, gestational diabetes, intrauterine growth restriction, incompetent cervix, premature rupture of membrane, incidence of abnormal placentation (placenta previa, accreta, increta, percreta, abruption), bleeding in pregnancy (antepartum or postpartum)
Time frame: Up to 15 months
Gestation Age at Delivery
Gestation age (weeks) at delivery per infant delivered
Time frame: Up to 15 months
Infant Birth Weight
Infant birth weight (gram) per infant delivered.
Time frame: Up to 15 months
| Milestone | Pre-IVF Treatment With 60 Day Course of Oral GnRH Antagonist | Pre-IVF Treatment With 60 Day Course of Placebo or SOC IVF |
|---|---|---|
| Started | 53 | 50 |
| Per protocol | 37 | 40 |
| Completed | 40 | 47 |
| Not completed | 13 | 3 |
| Withdrew: Withdrawal by subject | 13 | 3 |
The percentage of the number of participants with a live birth at ≥24 weeks of gestation out of those who were enrolled in the study
| Participants | Pre-IVF Treatment With 60 Day Course of Oral GnRH Antagonist | Pre-IVF Treatment With 60 Day Course of Placebo or SOC IVF |
|---|---|---|
| Live Birth Rate | 20 | 22 |
The percentage of the total number of fertilized oocytes (two pronuclei) out of the total number of injected/inseminated oocytes across all participants in each Arm/Group who had the current or previous IVF data
| Total no. oocytes injected/inseminated | Pre-IVF Treatment With 60 Day Course of Oral GnRH Antagonist | Pre-IVF Treatment With 60 Day Course of Placebo or SOC IVF |
|---|---|---|
| Fertilization Rate | 194 | 291 |
Number of embryos transferred per participant
| Number of embryos transferred | Pre-IVF Treatment With 60 Day Course of Oral GnRH Antagonist | Pre-IVF Treatment With 60 Day Course of Placebo or SOC IVF |
|---|---|---|
| Number of Embryos Transferred | 1.1 ± 0.3 | 1.0 ± 0.2 |
The percentage of the total number of gestation sacs visible by Ultrasound out of the total number of transferred embryos across all participants in each Arm/Group who completed embryo transfer
| Total no. of embryo transferred | Pre-IVF Treatment With 60 Day Course of Oral GnRH Antagonist | Pre-IVF Treatment With 60 Day Course of Placebo or SOC IVF |
|---|---|---|
| Implantation Rate | 22 | 23 |
The percentage of the number of participants with positive pregnancy tests following embryo transfer out of those who were enrolled in the study
| Participants | Pre-IVF Treatment With 60 Day Course of Oral GnRH Antagonist | Pre-IVF Treatment With 60 Day Course of Placebo or SOC IVF |
|---|---|---|
| Biochemical Pregnancy Rate | 26 | 29 |
The percentage of the number of participants with ultrasound evidence of intrauterine gestational sac with fetal cardiac activity out of those who were enrolled in the study
| Participants | Pre-IVF Treatment With 60 Day Course of Oral GnRH Antagonist | Pre-IVF Treatment With 60 Day Course of Placebo or SOC IVF |
|---|---|---|
| Clinical Pregnancy Rate | 22 | 24 |
Percentage of the number of participants with a pregnancy loss out of those who have achieved pregnancy
| Participants | Pre-IVF Treatment With 60 Day Course of Oral GnRH Antagonist | Pre-IVF Treatment With 60 Day Course of Placebo or SOC IVF |
|---|---|---|
| Miscarriage Rate | 5 | 8 |
Percentage of the number of participants who had the overall pregnancy complication out of those who have achieved pregnancy. Overall pregnancy complication including any of the following: preterm delivery, preeclampsia, gestational diabetes, intrauterine growth restriction, incompetent cervix, premature rupture of membrane, incidence of abnormal placentation (placenta previa, accreta, increta, percreta, abruption), bleeding in pregnancy (antepartum or postpartum)
| Participants | Pre-IVF Treatment With 60 Day Course of Oral GnRH Antagonist | Pre-IVF Treatment With 60 Day Course of Placebo or SOC IVF |
|---|---|---|
| Overall Pregnancy Complication Rate | 12 | 12 |
Gestation age (weeks) at delivery per infant delivered
| weeks | Pre-IVF Treatment With 60 Day Course of Oral GnRH Antagonist | Pre-IVF Treatment With 60 Day Course of Placebo or SOC IVF |
|---|---|---|
| Gestation Age at Delivery | 39.0 (37.6 to 39.4) | 37.6 (36.9 to 39.0) |
Infant birth weight (gram) per infant delivered.
| gram | Pre-IVF Treatment With 60 Day Course of Oral GnRH Antagonist | Pre-IVF Treatment With 60 Day Course of Placebo or SOC IVF |
|---|---|---|
| Infant Birth Weight | 3300 ± 520 | 3237 ± 502 |
Collected over UP to 16.5 months. Non-serious events are listed at a 5% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Pre-IVF Treatment With 60 Day Course of Oral GnRH Antagonist | 0/53 (0%) | 0/53 (0%) | 30/53 (56.6%) |
| Pre-IVF Treatment With 60 Day Course of Placebo or SOC IVF | 0/50 (0%) | 3/50 (6%) | 21/50 (42%) |
| Event | Pre-IVF Treatment With 60 Day Course of Oral GnRH Antagonist | Pre-IVF Treatment With 60 Day Course of Placebo or SOC IVF |
|---|---|---|
| Ectopic pregnancyPregnancy, puerperium and perinatal conditions | 0/53 | 1/50 |
| Congenital birth defectCongenital, familial and genetic disorders | 0/53 | 1/50 |
| Pre-eclampsia with severe featurePregnancy, puerperium and perinatal conditions | 0/53 | 1/50 |
| Event | Pre-IVF Treatment With 60 Day Course of Oral GnRH Antagonist | Pre-IVF Treatment With 60 Day Course of Placebo or SOC IVF |
|---|---|---|
| Complications during pregnancyPregnancy, puerperium and perinatal conditions | 12/26 | 12/29 |
| Complications in infants after birth deliveryPregnancy, puerperium and perinatal conditions | 7/20 | 7/20 |
| Complications in mother after birth deliveryPregnancy, puerperium and perinatal conditions | 5/20 | 7/22 |
| Hot flashesNervous system disorders | 14/53 | 1/50 |
| HeadachesNervous system disorders | 7/53 | 1/50 |
| NauseaGastrointestinal disorders | 3/53 | 0/50 |
| Age, Continuous(years) | Pre-IVF Treatment With 60 Day Course of Oral GnRH Antagonist | Pre-IVF Treatment With 60 Day Course of Placebo or SOC IVF | Total |
|---|---|---|---|
| Median | 36.0 (33.0 to 38.0) | 34.5 (32.0 to 37.0) | 35.0 (32.0 to 38.0) |
| Sex: Female, Male(Participants) | Pre-IVF Treatment With 60 Day Course of Oral GnRH Antagonist | Pre-IVF Treatment With 60 Day Course of Placebo or SOC IVF | Total |
|---|---|---|---|
| Female | 53 | 50 | 103 |
| Male | 0 | 0 | 0 |
| Ethnicity (NIH/OMB)(Participants) | Pre-IVF Treatment With 60 Day Course of Oral GnRH Antagonist | Pre-IVF Treatment With 60 Day Course of Placebo or SOC IVF | Total |
|---|---|---|---|
| Hispanic or Latino | 4 | 9 | 13 |
| Not Hispanic or Latino | 49 | 39 | 88 |
| Unknown or Not Reported | 0 | 2 | 2 |
| Race (NIH/OMB)(Participants) | Pre-IVF Treatment With 60 Day Course of Oral GnRH Antagonist | Pre-IVF Treatment With 60 Day Course of Placebo or SOC IVF | Total |
|---|---|---|---|
| American Indian or Alaska Native | 0 | 0 | 0 |
| Asian | 6 | 3 | 9 |
| Native Hawaiian or Other Pacific Islander | 1 | 0 | 1 |
| Black or African American | 7 | 2 | 9 |
| White | 38 | 42 | 80 |
| More than one race | 0 | 2 | 2 |
| Unknown or Not Reported | 1 | 1 | 2 |
| Body Mass Index (BMI)(kg/m^2) | Pre-IVF Treatment With 60 Day Course of Oral GnRH Antagonist | Pre-IVF Treatment With 60 Day Course of Placebo or SOC IVF | Total |
|---|---|---|---|
| Median | 26.3 (23.7 to 30.0) | 26.1 (22.7 to 28.9) | 26.2 (23.6 to 30.2) |
Documents are hosted by the registry — open the source record to download them.
Plan to share: Yes — We have a plan to submit data and samples collected by the trial to NICHD DASH. The informed consent will include permission to bank these samples. The processes included initial data and documentation preparation (e.g., codebooks, protocols, informed consent for data sharing), data quality control, and submission.
Supporting information: Study protocol, Sap, Icf, Csr
This study is completed, as verified in May 2026. You cannot join it, but the record below documents what was studied.
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