Oral GnRH Antagonist (Linzagolix) Versus Injectable GnRH Antagonist in Controlled Ovarian Stimulation for In Vitro Fertilization: A Randomized Controlled Non-Inferiority Trial With a Concurrent Comparator Cohort Undergoing Progestin-Primed Ovarian Stimulation (PPOS)

September 26, 2026 updated by: Centro A.M.B.R.A. (Associazione Medici e Biologi per la Riproduzione Assistita)

Women undergoing IVF/ICSI who are candidates for a GnRH-antagonist protocol are randomly assigned 1:1 to oral linzagolix or the standard injectable GnRH antagonist (ganirelix or cetrorelix). A third, non-randomized group of women with a clinical indication for progestin-primed ovarian stimulation (PPOS) - for example, a need for a freeze-all strategy - is enrolled concurrently as a comparator cohort. The randomized comparison (linzagolix vs. injectable antagonist) is the primary, non-inferiority analysis; the PPOS cohort provides an exploratory, non-randomized comparison, analyzed with adjustment for baseline differences.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

This is a single-center, prospective, randomized, controlled non-inferiority trial with a concurrent non-randomized comparator cohort, conducted at CENTRO AMBRA. Women eligible for a GnRH-antagonist protocol are randomized 1:1 to oral linzagolix or the injectable GnRH antagonist using a computer-generated permuted-block randomization sequence (block size of 4, no stratification); allocation is concealed until treatment initiation. A separate, concurrent cohort of women with a clinical indication for PPOS is enrolled as a non-randomized comparator; because assignment to this cohort reflects clinical criteria, it may differ systematically from the randomized arms - confounding by indication limited to the PPOS comparison. This is addressed through pre-specified multivariable adjustment and, where sample size permits, propensity-score methods; the PPOS comparison is interpreted as an association, the randomized comparison as supporting non-inferiority. As treatment is known to investigators and patients, there is no masking (open-label); oocyte and embryo assessment follows standardized, predefined procedures. A target of 40 participants per group (120 total) was defined based on the pre-specified non-inferiority margin of 2.0 MII oocytes. All participants undergo a routine clinical follow-up visit 5 days after oocyte pick-up."

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
120

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years to 42 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

Female

Description

Inclusion Criteria:

  • Female, aged 18 to 42 years
  • Indication for IVF/ICSI with controlled ovarian stimulation at CENTRO AMBRA
  • Population unselected for ovarian reserve (normal, poor, and high responders are eligible)
  • Written informed consent, including consent for off-label use of linzagolix and for data processing
  • For the two antagonist arms (Linzagolix and Injectable GnRH Antagonist): acceptance of randomization

Exclusion Criteria:

  • Known contraindications or hypersensitivity to the study drugs
  • Uterine pathology relevant to the study outcome (e.g., uterine malformations, significant submucosal fibroids)
  • Contraindications to pregnancy or to ovarian stimulation
  • Concurrent participation in another interfering interventional study

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: A - Linzagolix
Drug: Linzagolix

Description: Linzagolix Type: Drug Group: A Description: Linzagolix 200 mg administered orally once daily, started per center protocol (fixed stimulation day or upon appearance of the dominant follicle) and continued through the day of trigger. Investigational off-label use for suppression of the premature LH surge during controlled ovarian stimulation.
Active Comparator: B - Injectable GnRH Antagonist (Ganirelix/Cetrorelix)
Drug: Ganirelix ; Cetrorelix

Ganirelix Type: Drug Group: B Description: Ganirelix acetate 0.25 mg administered by daily subcutaneous injection, per fixed or flexible protocol according to center practice, to suppress the premature LH surge during controlled ovarian stimulation.

Cetrorelix Type: Drug Arm: B Description: Cetrorelix acetate 0.25 mg administered by daily subcutaneous injection, per fixed or flexible protocol according to center practice, to suppress the premature LH surge during controlled ovarian stimulation.
Active Comparator: C - PPOS (Progestin-Primed Ovarian Stimulation) Cohort
Drug: Medroxyprogesterone Acetate ; Micronized Progesterone

This is a non-randomized, concurrently enrolled comparator cohort (not part of the 1:1 randomization).

Medroxyprogesterone Acetate - Type: Drug - Arm: C - Description: Medroxyprogesterone acetate 10 mg/day administered orally from stimulation day 1-2 through the day of trigger, as part of a progestin-primed ovarian stimulation (PPOS) protocol with mandatory freeze-all strategy.

Micronized Progesterone - Type: Drug - Arm: C - Description: Micronized progesterone 100-200 mg/day administered orally from stimulation day 1-2 through the day of trigger, as part of a progestin-primed ovarian stimulation (PPOS) protocol with mandatory freeze-all strategy.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Number of Mature (MII) Oocytes Retrieved
Time Frame: At oocyte retrieval, approximately 36 hours after trigger (first study cycle)

Number of metaphase II (mature) oocytes collected at oocyte retrieval. Non-inferiority of linzagolix versus the injectable GnRH antagonist will be concluded if the lower bound of the 95% confidence interval for the adjusted mean difference in MII oocytes (adjusted for ovarian reserve, age, BMI, gonadotropin type and dose, and trigger type) excludes a loss greater than the pre-specified non-inferiority margin of 2.0 MII oocytes. An exploratory comparison with the PPOS cohort is also performed, adjusted for baseline confounders.
At oocyte retrieval, approximately 36 hours after trigger (first study cycle)

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Time Frame
Incidence of Premature LH Rise
Time Frame: From initiation of LH-suppressive treatment to the day of trigger (up to approximately 12 days)
From initiation of LH-suppressive treatment to the day of trigger (up to approximately 12 days)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Centro A.M.B.R.A. (Associazione Medici e Biologi per la Riproduzione Assistita)

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
September 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 1, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 1, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 24, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 24, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 28, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 30, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 26, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
September 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • LINZA-COS

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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