EndometriosisPhase 2APPOSENCT04002141
Assessment and Prevention of Pain During Ovarian Stimulation in Patients With Endometriosis
A Phase 2 study testing Letrozole in people with Endometriosis and Ovarian Hyperstimulation, run by University of California, San Francisco at 1 site in United States.
Trial summary
Randomized double blinded placebo-controlled trial to evaluate the impact of ovarian hyperstimulation on endometriosis-related symptoms and to evaluate the impact of letrozole use during ovarian hyperstimulation with respect to endometriosis-related symptoms, embryo/egg quality and quantity, and pregnancy rates. Read more about this study
- Who is it for?
- Ages 18 to 42 years, women onlyHealthy volunteers can take part
- Conditions the study is for
- Endometriosis, Ovarian Hyperstimulation
- What is being tested?
- Letrozole
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 60 participants
- Where
- 1 siteUnited States
- Study dates
- 17 Sep 2019to 1 Jan 2025
- Phase
- Phase 2
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 42 years
- Women only
- Healthy volunteers accepted
- Adult
Who may be able to join
- Age 18-42 years
- Planning to undergo controlled ovarian hyperstimulation
- Prior diagnosis of endometriosis by one of the following: (1) surgical diagnosis (2) endometrioma on pelvic ultrasound
- Planning to freeze all retrieved oocytes/embryos prior to transfer
Who cannot join
- Hypersensitivity to letrozole
- Any significant concurrent disease, illness, or psychiatric disorder that would compromise patient safety or compliance, interfere with consent, study participation, follow-up, or interpretation of study results
Trial locations and contacts
1 site in 1 country.
United States1 site
UCSF Center for Reproductive Health
San Francisco, California, 94158
About this study
Randomized double blinded placebo-controlled trial to evaluate the impact of ovarian hyperstimulation on endometriosis-related symptoms and to evaluate the impact of letrozole use during ovarian hyperstimulation with respect to endometriosis-related symptoms, embryo/egg quality and quantity, and pregnancy rates.
Read the detailed description
Randomized double blinded placebo-controlled trial to evaluate: (1) the impact of letrozole use during ovarian hyperstimulation with respect to endometriosis-related symptoms, embryo/egg quality and quantity, and pregnancy rates, (2) the impact of ovarian hyperstimulation on endometriosis-related symptoms.
There will be a total of 60 participants, 20 participants with endometriosis randomized to the placebo group, 20 participants with endometriosis randomized to the letrozole group and 20 control patients with no history of endometriosis. Letrozole and placebo medication will be started on the first day of gonadotropin injections and continued until the day of trigger shot. Medication will be restarted the night of egg retrieval and continued for 2 weeks post retrieval. Endometriosis associated symptoms will be evaluated using a survey modeled after the clinical survey developed by the World Endometriosis Research Foundation Endometriosis Phenome and Biobanking Harmonisation Project. Surveys will be administered at baseline ultrasound appointment for controlled ovarian hyperstimulation cycle, the day of trigger shot, 3 weeks following egg retrieval, 6 weeks following egg retrieval and 12 weeks following egg retrieval.
- Conditions
- Endometriosis, Ovarian Hyperstimulation
- Being tested
- Placebo oral tablet, Letrozole
- Keywords
- Endometriosis, Letrozole
- Medical subject headings
- Endometriosis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Placebo oral tabletDrug
1 tablet oral daily
LetrozoleDrug
5mg oral daily
| Study group | Role | What they receive |
|---|---|---|
| Endometriosis Letrozole | Experimental | Participants will be asked to take 5mg letrozole daily throughout their ovarian stimulation and for 2 weeks following retrieval. Participants will be blinded to their randomization to letrozole. Participants will be asked to complete surveys during their stimulation and up to 12 weeks following retrieval to evaluate endometriosis associated symptoms. Specifically, surveys will be administered at baseline ultrasound appointment for controlled ovarian hyperstimulation cycle, the day of trigger shot, 3 weeks following egg retrieval, 6 weeks following egg retrieval and 12 weeks following egg retrieval. There will be a total of 20 participants in this arm. Receives: Drug: Letrozole |
| Endometriosis Placebo | Placebo comparator | Participants will be asked to take one tablet placebo daily throughout their ovarian stimulation and for 2 weeks following retrieval. Participants will be blinded to their randomization to placebo. Participants will be asked to complete surveys during their stimulation and up to 12 weeks following retrieval to evaluate endometriosis associated symptoms. Specifically, surveys will be administered at baseline ultrasound appointment for controlled ovarian hyperstimulation cycle, the day of trigger shot, 3 weeks following egg retrieval, 6 weeks following egg retrieval and 12 weeks following egg retrieval. There will be a total of 20 participants in this arm. Receives: Drug: Placebo oral tablet |
| No Endometriosis Control | No intervention | Participants will be asked to complete surveys during their ovarian stimulation and up to 12 weeks following retrieval to evaluate symptoms of pelvic pain. Specifically, surveys will be administered at baseline ultrasound appointment for controlled ovarian hyperstimulation cycle, the day of trigger shot, 3 weeks following egg retrieval, 6 weeks following egg retrieval and 12 weeks following egg retrieval. There will be a total of 20 participants in this arm. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Average Delta in Endometriosis Pain Score Pre and Post Stimulation With and Without Use Of Letrozole
To evaluate how letrozole impacts pain scores throughout controlled ovarian hyperstimulation in patients with endometriosis. Pain scores will be evaluated using a 0-10 visual acuity scale, where 0 is no pain and 10 is the worst imaginable pain. The average delta between pre-stimulation pain score and day of trigger shot pain score will be compared between patients with endometriosis receiving placebo and with endometriosis receiving letrozole.
Measured: Baseline ultrasound (day 2 of menstrual cycle) and day 12 (average day of trigger shot).
Secondary outcomes (7)
Average Delta in Endometriosis Pain Score Pre and Post Stimulation of Patients Receiving Placebo Compared to No Endometriosis
To evaluate the impact of endometriosis on pain scores throughout controlled ovarian hyperstimulation. Pain scores will be evaluated using a 0-10 visual acuity scale, where 0 is no pain and 10 is the worst imaginable pain. The average delta between pre-stimulation pain score and day of trigger shot will be compared between patients with endometriosis receiving placebo and patients without endometriosis.
Measured: Baseline ultrasound (day 2 of menstrual cycle) and day 12 (average day of trigger shot).
Comparative Trends in Endometriosis Pain Score Pre and Post Stimulation of Patients With Endometriosis Receiving Either Placebo or Letrozole and Patients Without Endometriosis
To evaluate the impact of letrozole on endometriosis pain scores throughout controlled ovarian hyperstimulation. Pain scores will be evaluated using a 0-10 visual acuity scale, where 0 is no pain and 10 is the worst imaginable pain. The calculated change in pain scores from pre-stimulation through 12 weeks post retrieval will be compared between patients with endometriosis receiving placebo, patients with endometriosis receiving letrozole and patients without endometriosis.
Measured: Pre-stimulation through 12 weeks post retrieval. This time span varies per each patient's course of treatment but is typically 14 weeks in tota
Does Letrozole Impact Egg Quantity in Endometriosis Patients
To describe the impact of letrozole on egg quantity in patients with endometriosis receiving letrozole and those with endometriosis not receiving letrozole and those without endometriosis during controlled ovarian stimulation. The total arm aggregate number of MII eggs retrieved per baseline arm aggregate Antral Follicle Count will be compared between the three groups.
Measured: Baseline ultrasound (day 2 of menstrual cycle) and day 14 (average day of egg retrieval).
Follicular Fluid
To compare follicular fluid average estradiol levels between placebo, letrozole and control groups.
Measured: Baseline ultrasound (day 2 of menstrual cycle) and day 14 (average day of egg retrieval).
Pregnancy Outcomes
To compare pregnancy rates in the placebo, letrozole and control groups. Pregnancy will be defined as positive serum hCG after transfer of embryo. The rate will determined by positive hCG per transfer.
Measured: Up to 2 years.
Egg Maturity
To describe the impact of letrozole on egg maturity. Measured by number of MII eggs per total number eggs retrieved in patients with endometriosis receiving letrozole and those with endometriosis not receiving letrozole during controlled ovarian stimulation.
Measured: Baseline ultrasound to time of cryopreservation of eggs/embryos, which occurs within 7 days of retrieval..
Embryo Grade
To describe the impact of letrozole on embryo quality. Measured by the average total number of freezable quality embryos (6c or greater, grades 1-2 for symmetry and fragmentation) in patients with endometriosis receiving letrozole and those with endometriosis not receiving letrozole and those without endometriosis during controlled ovarian stimulation.
Measured: 2 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Jun 2019
- Study start17 Sep 2019
- Primary completion1 Oct 2023
- Study completion1 Jan 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for EndometriosisStudies of the same condition, open and under way.
- More trials run by University of California, San FranciscoThe sponsor's other registered studies.
- 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 2
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 60 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of California, San Francisco
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Marcelle I Cedars, Principal investigator, University of California, San Francisco
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04002141
- Sponsor's protocol ID
- 18-26544
- Acronym
- APPOSE
- Status last verified
- Jan 2026
- First submitted
- 28 May 2019
- Last updated
- 28 Jan 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No