Trial Outcomes & Findings for Pre-IVF Treatment With a GnRH Antagonist in Women With Endometriosis (NCT NCT04173169)
NCT ID: NCT04173169
Last Updated: 2026-06-12
Results Overview
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
Recruitment status
COMPLETED
Study phase
PHASE3
Target enrollment
103 participants
Primary outcome timeframe
Up to 15 months
Results posted on
2026-06-12
Participant Flow
Participant milestones
| Measure |
Pre-IVF Treatment With 60 Day Course of Oral GnRH Antagonist
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.
Elagolix 200 MG: Elagolix tablet
|
Pre-IVF Treatment With 60 Day Course of Placebo or SOC IVF
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.
Placebo or SOC IVF: Sugar pill manufactured to mimic Elagolix 200mg
|
|---|---|---|
|
Overall Study
STARTED
|
53
|
50
|
|
Overall Study
Per Protocol
|
37
|
40
|
|
Overall Study
COMPLETED
|
40
|
47
|
|
Overall Study
NOT COMPLETED
|
13
|
3
|
Reasons for withdrawal
| Measure |
Pre-IVF Treatment With 60 Day Course of Oral GnRH Antagonist
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.
Elagolix 200 MG: Elagolix tablet
|
Pre-IVF Treatment With 60 Day Course of Placebo or SOC IVF
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.
Placebo or SOC IVF: Sugar pill manufactured to mimic Elagolix 200mg
|
|---|---|---|
|
Overall Study
Withdrawal by Subject
|
13
|
3
|
Baseline Characteristics
Pre-IVF Treatment With a GnRH Antagonist in Women With Endometriosis
Baseline characteristics by cohort
| Measure |
Pre-IVF Treatment With 60 Day Course of Oral GnRH Antagonist
n=53 Participants
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.
Elagolix 200 MG: Elagolix tablet
|
Pre-IVF Treatment With 60 Day Course of Placebo or SOC IVF
n=50 Participants
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.
Placebo or SOC IVF: Sugar pill manufactured to mimic Elagolix 200mg
|
Total
n=103 Participants
Total of all reporting groups
|
|---|---|---|---|
|
Age, Continuous
|
36.0 years
n=9 Participants
|
34.5 years
n=27 Participants
|
35.0 years
n=267 Participants
|
|
Sex: Female, Male
Female
|
53 Participants
n=9 Participants
|
50 Participants
n=27 Participants
|
103 Participants
n=267 Participants
|
|
Sex: Female, Male
Male
|
0 Participants
n=9 Participants
|
0 Participants
n=27 Participants
|
0 Participants
n=267 Participants
|
|
Ethnicity (NIH/OMB)
Hispanic or Latino
|
4 Participants
n=9 Participants
|
9 Participants
n=27 Participants
|
13 Participants
n=267 Participants
|
|
Ethnicity (NIH/OMB)
Not Hispanic or Latino
|
49 Participants
n=9 Participants
|
39 Participants
n=27 Participants
|
88 Participants
n=267 Participants
|
|
Ethnicity (NIH/OMB)
Unknown or Not Reported
|
0 Participants
n=9 Participants
|
2 Participants
n=27 Participants
|
2 Participants
n=267 Participants
|
|
Race (NIH/OMB)
American Indian or Alaska Native
|
0 Participants
n=9 Participants
|
0 Participants
n=27 Participants
|
0 Participants
n=267 Participants
|
|
Race (NIH/OMB)
Asian
|
6 Participants
n=9 Participants
|
3 Participants
n=27 Participants
|
9 Participants
n=267 Participants
|
|
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
|
1 Participants
n=9 Participants
|
0 Participants
n=27 Participants
|
1 Participants
n=267 Participants
|
|
Race (NIH/OMB)
Black or African American
|
7 Participants
n=9 Participants
|
2 Participants
n=27 Participants
|
9 Participants
n=267 Participants
|
|
Race (NIH/OMB)
White
|
38 Participants
n=9 Participants
|
42 Participants
n=27 Participants
|
80 Participants
n=267 Participants
|
|
Race (NIH/OMB)
More than one race
|
0 Participants
n=9 Participants
|
2 Participants
n=27 Participants
|
2 Participants
n=267 Participants
|
|
Race (NIH/OMB)
Unknown or Not Reported
|
1 Participants
n=9 Participants
|
1 Participants
n=27 Participants
|
2 Participants
n=267 Participants
|
|
Body Mass Index (BMI)
|
26.3 kg/m^2
n=9 Participants
|
26.1 kg/m^2
n=27 Participants
|
26.2 kg/m^2
n=267 Participants
|
PRIMARY outcome
Timeframe: Up to 15 monthsThe percentage of the number of participants with a live birth at ≥24 weeks of gestation out of those who were enrolled in the study
Outcome measures
| Measure |
Pre-IVF Treatment With 60 Day Course of Oral GnRH Antagonist
n=53 Participants
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.
Elagolix 200 MG: Elagolix tablet
|
Pre-IVF Treatment With 60 Day Course of Placebo or SOC IVF
n=50 Participants
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.
Placebo or SOC IVF: Sugar pill manufactured to mimic Elagolix 200mg
|
|---|---|---|
|
Live Birth Rate
|
20 Participants
|
22 Participants
|
SECONDARY outcome
Timeframe: Up to 9 monthsPopulation: For participants who had current or previous IVF data
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
Outcome measures
| Measure |
Pre-IVF Treatment With 60 Day Course of Oral GnRH Antagonist
n=333 Total no. oocytes injected/inseminated
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.
Elagolix 200 MG: Elagolix tablet
|
Pre-IVF Treatment With 60 Day Course of Placebo or SOC IVF
n=477 Total no. oocytes injected/inseminated
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.
Placebo or SOC IVF: Sugar pill manufactured to mimic Elagolix 200mg
|
|---|---|---|
|
Fertilization Rate
|
194 Total no. oocytes injected/inseminated
|
291 Total no. oocytes injected/inseminated
|
SECONDARY outcome
Timeframe: Up to 9 monthsNumber of embryos transferred per participant
Outcome measures
| Measure |
Pre-IVF Treatment With 60 Day Course of Oral GnRH Antagonist
n=34 Participants
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.
Elagolix 200 MG: Elagolix tablet
|
Pre-IVF Treatment With 60 Day Course of Placebo or SOC IVF
n=40 Participants
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.
Placebo or SOC IVF: Sugar pill manufactured to mimic Elagolix 200mg
|
|---|---|---|
|
Number of Embryos Transferred
|
1.1 Number of embryos transferred
Standard Deviation 0.3
|
1.0 Number of embryos transferred
Standard Deviation 0.2
|
SECONDARY outcome
Timeframe: Up to 9 monthsPopulation: For those who completed embryo transfer
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
Outcome measures
| Measure |
Pre-IVF Treatment With 60 Day Course of Oral GnRH Antagonist
n=38 Total no. of embryo transferred
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.
Elagolix 200 MG: Elagolix tablet
|
Pre-IVF Treatment With 60 Day Course of Placebo or SOC IVF
n=42 Total no. of embryo transferred
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.
Placebo or SOC IVF: Sugar pill manufactured to mimic Elagolix 200mg
|
|---|---|---|
|
Implantation Rate
|
22 Total no. of embryo transferred
|
23 Total no. of embryo transferred
|
SECONDARY outcome
Timeframe: Up to 9 monthsThe percentage of the number of participants with positive pregnancy tests following embryo transfer out of those who were enrolled in the study
Outcome measures
| Measure |
Pre-IVF Treatment With 60 Day Course of Oral GnRH Antagonist
n=53 Participants
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.
Elagolix 200 MG: Elagolix tablet
|
Pre-IVF Treatment With 60 Day Course of Placebo or SOC IVF
n=50 Participants
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.
Placebo or SOC IVF: Sugar pill manufactured to mimic Elagolix 200mg
|
|---|---|---|
|
Biochemical Pregnancy Rate
|
26 Participants
|
29 Participants
|
SECONDARY outcome
Timeframe: Up to 10 monthsThe 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
Outcome measures
| Measure |
Pre-IVF Treatment With 60 Day Course of Oral GnRH Antagonist
n=53 Participants
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.
Elagolix 200 MG: Elagolix tablet
|
Pre-IVF Treatment With 60 Day Course of Placebo or SOC IVF
n=50 Participants
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.
Placebo or SOC IVF: Sugar pill manufactured to mimic Elagolix 200mg
|
|---|---|---|
|
Clinical Pregnancy Rate
|
22 Participants
|
24 Participants
|
SECONDARY outcome
Timeframe: Up to 10 monthsPopulation: Participants who achieved pregnancy
Percentage of the number of participants with a pregnancy loss out of those who have achieved pregnancy
Outcome measures
| Measure |
Pre-IVF Treatment With 60 Day Course of Oral GnRH Antagonist
n=26 Participants
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.
Elagolix 200 MG: Elagolix tablet
|
Pre-IVF Treatment With 60 Day Course of Placebo or SOC IVF
n=29 Participants
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.
Placebo or SOC IVF: Sugar pill manufactured to mimic Elagolix 200mg
|
|---|---|---|
|
Miscarriage Rate
|
5 Participants
|
8 Participants
|
SECONDARY outcome
Timeframe: Up to 15 monthsPopulation: Participants who achieved pregnancy
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)
Outcome measures
| Measure |
Pre-IVF Treatment With 60 Day Course of Oral GnRH Antagonist
n=26 Participants
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.
Elagolix 200 MG: Elagolix tablet
|
Pre-IVF Treatment With 60 Day Course of Placebo or SOC IVF
n=29 Participants
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.
Placebo or SOC IVF: Sugar pill manufactured to mimic Elagolix 200mg
|
|---|---|---|
|
Overall Pregnancy Complication Rate
|
12 Participants
|
12 Participants
|
SECONDARY outcome
Timeframe: Up to 15 monthsPopulation: Participants who delivered live baby and had the gestation age data
Gestation age (weeks) at delivery per infant delivered
Outcome measures
| Measure |
Pre-IVF Treatment With 60 Day Course of Oral GnRH Antagonist
n=19 Participants
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.
Elagolix 200 MG: Elagolix tablet
|
Pre-IVF Treatment With 60 Day Course of Placebo or SOC IVF
n=22 Participants
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.
Placebo or SOC IVF: Sugar pill manufactured to mimic Elagolix 200mg
|
|---|---|---|
|
Gestation Age at Delivery
|
39.0 weeks
Interval 37.6 to 39.4
|
37.6 weeks
Interval 36.9 to 39.0
|
SECONDARY outcome
Timeframe: Up to 15 monthsPopulation: Participants who delivered live baby and had infant birth weight data
Infant birth weight (gram) per infant delivered.
Outcome measures
| Measure |
Pre-IVF Treatment With 60 Day Course of Oral GnRH Antagonist
n=18 Participants
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.
Elagolix 200 MG: Elagolix tablet
|
Pre-IVF Treatment With 60 Day Course of Placebo or SOC IVF
n=19 Participants
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.
Placebo or SOC IVF: Sugar pill manufactured to mimic Elagolix 200mg
|
|---|---|---|
|
Infant Birth Weight
|
3300 gram
Standard Deviation 520
|
3237 gram
Standard Deviation 502
|
Adverse Events
Pre-IVF Treatment With 60 Day Course of Oral GnRH Antagonist
Serious events: 0 serious events
Other events: 30 other events
Deaths: 0 deaths
Pre-IVF Treatment With 60 Day Course of Placebo or SOC IVF
Serious events: 3 serious events
Other events: 21 other events
Deaths: 0 deaths
Serious adverse events
| Measure |
Pre-IVF Treatment With 60 Day Course of Oral GnRH Antagonist
n=53 participants at risk
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.
Elagolix 200 MG: Elagolix tablet
|
Pre-IVF Treatment With 60 Day Course of Placebo or SOC IVF
n=50 participants at risk
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.
Placebo or SOC IVF: Sugar pill manufactured to mimic Elagolix 200mg
|
|---|---|---|
|
Pregnancy, puerperium and perinatal conditions
Pre-eclampsia with severe feature
|
0.00%
0/53 • UP to 16.5 months
An adverse event or serious adverse event will be collected/recorded during study visits and interviews of a study participant presenting for medical care, or upon review by a study monitor
|
2.0%
1/50 • Number of events 1 • UP to 16.5 months
An adverse event or serious adverse event will be collected/recorded during study visits and interviews of a study participant presenting for medical care, or upon review by a study monitor
|
|
Pregnancy, puerperium and perinatal conditions
Ectopic pregnancy
|
0.00%
0/53 • UP to 16.5 months
An adverse event or serious adverse event will be collected/recorded during study visits and interviews of a study participant presenting for medical care, or upon review by a study monitor
|
2.0%
1/50 • Number of events 1 • UP to 16.5 months
An adverse event or serious adverse event will be collected/recorded during study visits and interviews of a study participant presenting for medical care, or upon review by a study monitor
|
|
Congenital, familial and genetic disorders
Congenital birth defect
|
0.00%
0/53 • UP to 16.5 months
An adverse event or serious adverse event will be collected/recorded during study visits and interviews of a study participant presenting for medical care, or upon review by a study monitor
|
2.0%
1/50 • Number of events 1 • UP to 16.5 months
An adverse event or serious adverse event will be collected/recorded during study visits and interviews of a study participant presenting for medical care, or upon review by a study monitor
|
Other adverse events
| Measure |
Pre-IVF Treatment With 60 Day Course of Oral GnRH Antagonist
n=53 participants at risk
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.
Elagolix 200 MG: Elagolix tablet
|
Pre-IVF Treatment With 60 Day Course of Placebo or SOC IVF
n=50 participants at risk
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.
Placebo or SOC IVF: Sugar pill manufactured to mimic Elagolix 200mg
|
|---|---|---|
|
Nervous system disorders
Hot flashes
|
26.4%
14/53 • Number of events 19 • UP to 16.5 months
An adverse event or serious adverse event will be collected/recorded during study visits and interviews of a study participant presenting for medical care, or upon review by a study monitor
|
2.0%
1/50 • Number of events 1 • UP to 16.5 months
An adverse event or serious adverse event will be collected/recorded during study visits and interviews of a study participant presenting for medical care, or upon review by a study monitor
|
|
Nervous system disorders
Headaches
|
13.2%
7/53 • Number of events 8 • UP to 16.5 months
An adverse event or serious adverse event will be collected/recorded during study visits and interviews of a study participant presenting for medical care, or upon review by a study monitor
|
2.0%
1/50 • Number of events 2 • UP to 16.5 months
An adverse event or serious adverse event will be collected/recorded during study visits and interviews of a study participant presenting for medical care, or upon review by a study monitor
|
|
Gastrointestinal disorders
Nausea
|
5.7%
3/53 • Number of events 4 • UP to 16.5 months
An adverse event or serious adverse event will be collected/recorded during study visits and interviews of a study participant presenting for medical care, or upon review by a study monitor
|
0.00%
0/50 • UP to 16.5 months
An adverse event or serious adverse event will be collected/recorded during study visits and interviews of a study participant presenting for medical care, or upon review by a study monitor
|
|
Pregnancy, puerperium and perinatal conditions
Complications during pregnancy
|
46.2%
12/26 • Number of events 12 • UP to 16.5 months
An adverse event or serious adverse event will be collected/recorded during study visits and interviews of a study participant presenting for medical care, or upon review by a study monitor
|
41.4%
12/29 • Number of events 12 • UP to 16.5 months
An adverse event or serious adverse event will be collected/recorded during study visits and interviews of a study participant presenting for medical care, or upon review by a study monitor
|
|
Pregnancy, puerperium and perinatal conditions
Complications in mother after birth delivery
|
25.0%
5/20 • Number of events 5 • UP to 16.5 months
An adverse event or serious adverse event will be collected/recorded during study visits and interviews of a study participant presenting for medical care, or upon review by a study monitor
|
31.8%
7/22 • Number of events 7 • UP to 16.5 months
An adverse event or serious adverse event will be collected/recorded during study visits and interviews of a study participant presenting for medical care, or upon review by a study monitor
|
|
Pregnancy, puerperium and perinatal conditions
Complications in infants after birth delivery
|
35.0%
7/20 • Number of events 7 • UP to 16.5 months
An adverse event or serious adverse event will be collected/recorded during study visits and interviews of a study participant presenting for medical care, or upon review by a study monitor
|
35.0%
7/20 • Number of events 7 • UP to 16.5 months
An adverse event or serious adverse event will be collected/recorded during study visits and interviews of a study participant presenting for medical care, or upon review by a study monitor
|
Additional Information
Dr. Heping Zhang, Director of the Data Coordinating Center of the Consortium
Yale University
Phone: 203-785-5185
Email: [email protected]
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place