PCOS (Polycystic Ovary Syndrome)PROLEx-PCOSNCT07159880
Letrozole Extended vs Traditional Therapy for Ovulation Induction in Women With PCOS (PROLEx-PCOS)
A study testing Traditional Letrozole Therapy and Extended Letrozole Therapy in people with PCOS (Polycystic Ovary Syndrome) and Infertility, run by GABRIEL MONTEIRO PINHEIRO at 1 site in Brazil.
Trial summary
This randomized clinical trial aims to compare the efficacy and safety of extended letrozole therapy (5 mg/day for 10 days) versus standard letrozole therapy (5 mg/day for 5 days) for ovulation induction in women with polycystic ovary syndrome (PCOS). Read more about this study
- Who is it for?
- Ages 18 to 40 years, women onlyHealthy volunteers can take part
- Conditions the study is for
- PCOS (Polycystic Ovary Syndrome), Infertility, Anovulation
- What is being tested?
- Traditional Letrozole Therapy and Extended Letrozole Therapy
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 20 participants
- Where
- 1 siteBrazil
- Study dates
- 1 Sep 2025to 30 Jul 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 40 years
- Women only
- Healthy volunteers accepted
- Adult
Who may be able to join
- Women aged 18 to 40 years;
- BMI between 18,5 and 31 kg/m2
- Diagnosis of Polycystic Ovary Syndrome (PCOS) according to the Rotterdam criteria (2003) (presence of at least two of the following: oligo/anovulation, clinical and/or biochemical hyperandrogenism, polycystic ovarian morphology on ultrasound);
- Active desire for pregnancy at the time of enrollment;
- Ability and willingness to provide written informed consent (ICF).
Who cannot join
- Age <18 or >40 years;
- Presence of confirmed bilateral tubal factor, severe male factor infertility, premature ovarian insufficiency, uncontrolled hyperprolactinemia or thyroid dysfunction);
- Congenital or acquired uterine malformations;
- History of gynecologic or breast cancer;
- Known hypersensitivity to, or contraindication for, letrozole;
- Severe uncontrolled systemic disease (e.g., cardiovascular, renal, or hepatic disorders);
- Pregnancy or breastfeeding at the time of screening.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Brazil1 site, 1 recruiting
- Recruiting
Health Complex Dr Wladimir Arruda
São Paulo, São Paulo, 04829-310
Gabriel M Pinheiro, MD, +55(11)97130-7240, Drg.monteiro@hotmail.com
Katherine Ann R Miller, Undergraduate medical student, +55 (11) 96409-8358, katherinereimao000@gmail.com
About this study
Official title: Extended Therapy Versus Traditional Therapy With Letrozole for Ovulation Induction in Women With Polycystic Ovary Syndrome: A Randomized Controlled Trial
This randomized clinical trial aims to compare the efficacy and safety of extended letrozole therapy (5 mg/day for 10 days) versus standard letrozole therapy (5 mg/day for 5 days) for ovulation induction in women with polycystic ovary syndrome (PCOS). A total of 84 women aged 18-40 years will be randomized into two groups. Ovulation will be monitored by transvaginal ultrasound and confirmed with urinary LH testing and/or corpus luteum presence. The primary outcome is ovulation rate, while secondary outcomes include number and size of mature follicles, clinical pregnancy rate, multiple pregnancy rate, miscarriage rate, number of cycles until pregnancy, and incidence of ovarian hyperstimulation syndrome (OHSS).
Read the detailed description
Polycystic ovary syndrome (PCOS) is a prevalent endocrine disorder and one of the leading causes of anovulatory infertility worldwide. Letrozole, an aromatase inhibitor, has emerged as the preferred first-line pharmacological agent for ovulation induction in women with PCOS. Despite its widespread use, there is ongoing debate regarding the optimal duration of therapy to maximize ovulatory and pregnancy outcomes.
This randomized clinical trial is designed to evaluate whether an extended regimen of letrozole provides superior reproductive outcomes compared with the standard regimen. The extended protocol consists of daily administration of 5 mg letrozole from cycle day 2 through day 12, whereas the standard regimen involves 5 mg daily from cycle day 2 through day 6. Ovulatory response will be monitored through serial transvaginal ultrasound and biochemical markers of ovulation.
The trial aims to generate high-quality evidence on the efficacy and safety of extended letrozole therapy. The findings may inform future clinical guidelines on ovulation induction strategies in women with PCOS and contribute to optimizing treatment protocols for anovulatory infertility.
- Conditions
- PCOS (Polycystic Ovary Syndrome), Infertility, Anovulation
- Being tested
- Traditional Letrozole Therapy, Extended Letrozole Therapy
- Keywords
- polycystic ovary syndrome, PCOS, Ovulation induction, Letrozole, Aromatase Inhibitor, Extended letrozole therapy, traditional letrozole therapy, standart letrozole therapy, infertility, anovulation, ovulation rate, pregnancy rate
- Medical subject headings
- Polycystic Ovary Syndrome, Infertility, Anovulation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Traditional Letrozole TherapyDrug
Traditional therapy group: 5 mg/day of letrozole for 5 days (cycle days 2-6).
Extended Letrozole TherapyDrug
Extended therapy group: 5 mg/day of letrozole for 10 days (cycle days 2-12)
| Study group | Role | What they receive |
|---|---|---|
| Traditional Letrozole Therapy | Active comparator | Participants in this group will receive standard letrozole therapy for ovulation induction. Letrozole will be administered orally at a dose of 5 mg/day from cycle day 2 through cycle day 6 (5 consecutive days). Ovulation monitoring will be performed by transvaginal ultrasound and confirmed with urinary LH testing and/or corpus luteum visualization. This arm serves as the active comparator against the extended regimen for evaluating efficacy and safety outcomes. Receives: Drug: Traditional Letrozole Therapy |
| Extended Letrozole Therapy | Experimental | Participants in this group will receive extended letrozole therapy for ovulation induction. Letrozole will be administered orally at a dose of 5 mg/day from cycle day 2 through cycle day 12 (10 consecutive days). Ovulation monitoring will be performed by transvaginal ultrasound and confirmed with urinary LH testing and/or corpus luteum visualization. This arm will be compared with the standard regimen to assess differences in ovulation rate, follicular development, pregnancy outcomes, and safety. Receives: Drug: Extended Letrozole Therapy |
What is being measured
The primary outcome is the main question the study is designed to answer.
Ovulation rate
Proportion of participants achieving ovulation, defined as the presence of a dominant follicle ≥18 mm on transvaginal ultrasound with confirmation by urinary LH surge and/or visualization of corpus luteum.
Measured: Assessed within one treatment cycle (up to 6 weeks from the start of medication).
Secondary outcomes (6)
Clinical Pregnancy Rate
Proportion of participants achieving clinical pregnancy, defined as visualization of a gestational sac by transvaginal ultrasound.
Measured: Assessed within 8 weeks after the start of treatment.
Number of Mature Follicles
Number of follicles ≥18 mm observed by transvaginal ultrasound in the stimulated cycle.
Measured: Assessed during one treatment cycle (up to 6 weeks).
Follicular Size
Maximum diameter (in millimeters) of the leading follicle(s) observed by transvaginal ultrasound.
Measured: Assessed during one treatment cycle (up to 6 weeks).
Miscarriage Rate
Proportion of participants with spontaneous pregnancy loss within the first trimester (<12 weeks of gestation).
Measured: Assessed up to 12 weeks of gestation.
Multiple Pregnancy Rate
Proportion of participants with multiple gestations, confirmed by transvaginal ultrasound.
Measured: Assessed within 8 weeks after the start of treatment.
Incidence of Ovarian Hyperstimulation Syndrome (OHSS)
Proportion of participants presenting clinical or ultrasound signs of OHSS during treatment.
Measured: Assessed within one treatment cycle (up to 6 weeks).
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 Sep 2025
- Study start1 Sep 2025
- Primary completion30 Jul 2026 (estimated)
- Study completion30 Jul 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for PCOS (Polycystic Ovary Syndrome)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- This is a randomized, controlled, parallel assignment clinical trial designed to compare extended letrozole therapy with standard letrozole therapy for ovulation induction in women with polycystic ovary syndrome (PCOS). Participants will be randomized in a 1:1 ratio into two groups: extended therapy (letrozole 5 mg/day from cycle days 2-12) and standard therapy (letrozole 5 mg/day from cycle days 2-6). Ovulation will be monitored by transvaginal ultrasound and confirmed with urinary LH testing. The primary outcome is ovulation rate. Secondary outcomes include number and size of mature follicles, clinical pregnancy rate, miscarriage rate, multiple pregnancy rate, time to conception, and incidence of ovarian hyperstimulation syndrome (OHSS).
- Masking
- None (open label)
- Enrolment
- 20 participants (estimated)
Sponsor and investigators
- Lead sponsor
- GABRIEL MONTEIRO PINHEIRO
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, GABRIEL MONTEIRO PINHEIRO, EMBRIONARE
- Investigators
- Gabriel M Pinheiro, MD, Study director, Universidade Santo AmaroKatherine Ann R Miller, Medical student, Principal investigator, Universisty of Santo Amaro
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07159880
- Sponsor's protocol ID
- 88592925.0.0000.0081
- Acronym
- PROLEx-PCOS
- Status last verified
- Nov 2025
- First submitted
- 29 Aug 2025
- Last updated
- 28 Nov 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Data obtained through this study may be shared with qualified researchers with academic interest in polycystic ovary syndrome (PCOS), ovulation induction, or related reproductive medicine topics. Any shared data will be de-identified and coded, with no personal health information (PHI) included. Approval of the request by the principal investigator and execution of all applicable agreements (e.g., data use agreement or material transfer agreement) will be required prior to data sharing.
Study at a glance
From the registry record, last updated by the sponsor on 28 Nov 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Extended Therapy Versus Traditional Therapy With Letrozole for Ovulation Induction in Women With Polycystic Ovary Syndrome: A Randomized Controlled Trial
- ClinicalTrials.gov ID
- NCT07159880
- Acronym / sponsor ID
- PROLEx-PCOS / 88592925.0.0000.0081
- Conditions
- PCOS (Polycystic Ovary Syndrome), Infertility, Anovulation
- Keywords
- polycystic ovary syndrome, PCOS, Ovulation induction, Letrozole, Aromatase Inhibitor, Extended letrozole therapy, traditional letrozole therapy, standart letrozole therapy
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 20 participants (estimated)
- Lead sponsor
- GABRIEL MONTEIRO PINHEIROUniversity, hospital or other
- Study start
- 1 Sep 2025 (actual)
- Primary completion
- 30 Jul 2026 (estimated)
- Study completion
- 30 Jul 2026 (estimated)
- First posted
- 8 Sep 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This randomized clinical trial aims to compare the efficacy and safety of extended letrozole therapy (5 mg/day for 10 days) versus standard letrozole therapy (5 mg/day for 5 days) for ovulation induction in women with polycystic ovary syndrome (PCOS). A total of 84 women aged 18-40 years will be randomized into two groups. Ovulation will be monitored by transvaginal ultrasound and confirmed with urinary LH testing and/or corpus luteum presence. The primary outcome is ovulation rate, while secondary outcomes include number and size of mature follicles, clinical pregnancy rate, multiple pregnancy rate, miscarriage rate, number of cycles until pregnancy, and incidence of ovarian hyperstimulation syndrome (OHSS).
Detailed description
Polycystic ovary syndrome (PCOS) is a prevalent endocrine disorder and one of the leading causes of anovulatory infertility worldwide. Letrozole, an aromatase inhibitor, has emerged as the preferred first-line pharmacological agent for ovulation induction in women with PCOS. Despite its widespread use, there is ongoing debate regarding the optimal duration of therapy to maximize ovulatory and pregnancy outcomes.
This randomized clinical trial is designed to evaluate whether an extended regimen of letrozole provides superior reproductive outcomes compared with the standard regimen. The extended protocol consists of daily administration of 5 mg letrozole from cycle day 2 through day 12, whereas the standard regimen involves 5 mg daily from cycle day 2 through day 6. Ovulatory response will be monitored through serial transvaginal ultrasound and biochemical markers of ovulation.
The trial aims to generate high-quality evidence on the efficacy and safety of extended letrozole therapy. The findings may inform future clinical guidelines on ovulation induction strategies in women with PCOS and contribute to optimizing treatment protocols for anovulatory infertility.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- This is a randomized, controlled, parallel assignment clinical trial designed to compare extended letrozole therapy with standard letrozole therapy for ovulation induction in women with polycystic ovary syndrome (PCOS). Participants will be randomized in a 1:1 ratio into two groups: extended therapy (letrozole 5 mg/day from cycle days 2-12) and standard therapy (letrozole 5 mg/day from cycle days 2-6). Ovulation will be monitored by transvaginal ultrasound and confirmed with urinary LH testing. The primary outcome is ovulation rate. Secondary outcomes include number and size of mature follicles, clinical pregnancy rate, miscarriage rate, multiple pregnancy rate, time to conception, and incidence of ovarian hyperstimulation syndrome (OHSS).
| Arm | Type | Receives |
|---|---|---|
| Traditional Letrozole Therapy | Active comparator | Drug: Traditional Letrozole TherapyParticipants in this group will receive standard letrozole therapy for ovulation induction. Letrozole will be administered orally at a dose of 5 mg/day from cycle day 2 through cycle day 6 (5 consecutive days). Ovulation monitoring will be performed by transvaginal ultrasound and confirmed with urinary LH testing and/or corpus luteum visualization. This arm serves as the active comparator against the extended regimen for evaluating efficacy and safety outcomes. |
| Extended Letrozole Therapy | Experimental | Drug: Extended Letrozole TherapyParticipants in this group will receive extended letrozole therapy for ovulation induction. Letrozole will be administered orally at a dose of 5 mg/day from cycle day 2 through cycle day 12 (10 consecutive days). Ovulation monitoring will be performed by transvaginal ultrasound and confirmed with urinary LH testing and/or corpus luteum visualization. This arm will be compared with the standard regimen to assess differences in ovulation rate, follicular development, pregnancy outcomes, and safety. |
Who may qualify
- Ages
- 18 to 40 years
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- Women aged 18 to 40 years;
- BMI between 18,5 and 31 kg/m2
- Diagnosis of Polycystic Ovary Syndrome (PCOS) according to the Rotterdam criteria (2003) (presence of at least two of the following: oligo/anovulation, clinical and/or biochemical hyperandrogenism, polycystic ovarian morphology on ultrasound);
- Active desire for pregnancy at the time of enrollment;
- Ability and willingness to provide written informed consent (ICF).
Key exclusion criteria (7 listed)
- Age <18 or >40 years;
- Presence of confirmed bilateral tubal factor, severe male factor infertility, premature ovarian insufficiency, uncontrolled hyperprolactinemia or thyroid dysfunction);
- Congenital or acquired uterine malformations;
- History of gynecologic or breast cancer;
- Known hypersensitivity to, or contraindication for, letrozole;
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Traditional Letrozole TherapyTraditional therapy group: 5 mg/day of letrozole for 5 days (cycle days 2-6). | Drug | Traditional Letrozole Therapy |
| Extended Letrozole TherapyExtended therapy group: 5 mg/day of letrozole for 10 days (cycle days 2-12) | Drug | Extended Letrozole Therapy |
Primary outcome
Ovulation rate
Time frame: Assessed within one treatment cycle (up to 6 weeks from the start of medication).
Proportion of participants achieving ovulation, defined as the presence of a dominant follicle ≥18 mm on transvaginal ultrasound with confirmation by urinary LH surge and/or visualization of corpus luteum.
6 secondary outcomes
Clinical Pregnancy Rate
Time frame: Assessed within 8 weeks after the start of treatment.
Number of Mature Follicles
Time frame: Assessed during one treatment cycle (up to 6 weeks).
Follicular Size
Time frame: Assessed during one treatment cycle (up to 6 weeks).
Miscarriage Rate
Time frame: Assessed up to 12 weeks of gestation.
Multiple Pregnancy Rate
Time frame: Assessed within 8 weeks after the start of treatment.
Incidence of Ovarian Hyperstimulation Syndrome (OHSS)
Time frame: Assessed within one treatment cycle (up to 6 weeks).
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 28 Nov 2025.
- Individual participant dataSharing planned: Yes. Data obtained through this study may be shared with qualified researchers with academic interest in polycystic ovary syndrome (PCOS), ovulation induction, or related reproductive medicine topics. Any shared data will be de-identified and coded, with no personal health information (PHI) included. Approval of the request by the principal investigator and execution of all applicable agreements (e.g., data use agreement or material transfer agreement) will be required prior to data sharing.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Gabriel M Pinheiro, MD study director
Universidade Santo Amaro
Katherine Ann R Miller, Medical student principal investigator
Universisty of Santo Amaro
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Traditional Letrozole Therapy and Extended Letrozole Therapy in people with PCOS (Polycystic Ovary Syndrome) and Infertility, run by GABRIEL MONTEIRO PINHEIRO at 1 site in Brazil.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 28 Nov 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Brazil. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Katherine Ann R Miller, Medical student (+55(11) 964098358, katherinereimao000@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Ovulation rate (time frame: Assessed within one treatment cycle (up to 6 weeks from the start of medication).). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 28 Nov 2025.