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Study on the Effectiveness and Safety of OG-6219 and Naproxen Sodium for Women Aged 18-49 with Moderate to Severe Endometriosis Pain

Fast replyRegistered drugNo placebo
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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying the effectiveness and safety of a new medication called OG-6219 for women aged 18 to 49 who experience moderate to severe pain due to endometriosis. Endometriosis is a condition where tissue similar to the lining inside the uterus grows outside of it, causing pain and sometimes fertility problems. The study will compare three different doses of OG-6219 with a placebo to see how well it reduces pelvic pain associated with endometriosis.

Participants in the study will take the medication or placebo twice a day. The study will last for several months, during which participants will be asked to record their pain levels and any side effects they experience. The goal is to determine if OG-6219 can effectively reduce pain and to assess its safety for long-term use. The study will also monitor any changes in participants' health through regular check-ups and tests.

In addition to OG-6219, the study involves the use of naproxen sodium, a common pain reliever, as a rescue medication for participants who need additional pain relief. The study aims to provide valuable information on whether OG-6219 can be a new treatment option for managing endometriosis-related pain, potentially improving the quality of life for those affected by this condition.

The research process

The trial runs in 6 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial visit and consent

    Upon joining the study, you will attend an initial visit where you will be asked to provide signed informed consent. This is a document that confirms your understanding and agreement to participate in the study.

    During this visit, you will undergo a series of assessments to confirm your eligibility, including a review of your medical history and a physical examination.

  2. Step 2

    Screening and baseline cycle

    You will enter a screening phase where your eligibility will be further assessed. This includes maintaining an electronic diary (eDiary) to record your pelvic pain, vaginal bleeding, and any use of rescue medication.

    You will be required to demonstrate compliance with at least 75% of the eDiary entries and take only the study-provided rescue medication during this period.

  3. Step 3

    Placebo run-in phase

    Before the main treatment phase, you will enter a placebo run-in phase. During this time, you will take placebo tablets to ensure compliance with the study protocol.

    Your compliance with taking the placebo tablets will be assessed, and you must achieve at least 80% compliance.

  4. Step 4

    Randomization and treatment

    Once eligibility is confirmed, you will be randomly assigned to one of four groups. Three groups will receive different dose levels of the study medication OG-6219, and one group will receive a placebo.

    The study medication or placebo will be taken orally twice a day. The dose levels for OG-6219 are 50 mg, 100 mg, or 150 mg.

  5. Step 5

    Treatment cycles

    You will undergo three treatment cycles, during which you will continue to record your symptoms and any use of rescue medication in the eDiary.

    Your overall pelvic pain will be evaluated using a numeric rating scale, and you will attend regular study visits for assessments, including transvaginal ultrasound and blood tests.

  6. Step 6

    Follow-up and final assessments

    After completing the treatment cycles, you will have follow-up visits to assess your response to the treatment and any side effects.

    Final assessments will include a review of your eDiary entries, physical examinations, and laboratory tests to ensure your safety and evaluate the study's outcomes.

Who can join the trial?

14 criteria

  • Must be a pre-menopausal female aged 18 to 49 years old.
  • Must have moderate to severe endometriosis-related pelvic pain during the last menstrual cycle, with a pain score of 4 or higher on a scale from 0 (no pain) to 10 (extremely severe pain).
  • Must have been diagnosed with endometriosis through surgery within the last 4 months to 10 years.
  • Must have regular menstrual cycles without hormonal therapy, with a cycle length between 21 to 32 days, for the past month.
  • Must not be planning to have any gynecological surgery or other procedures for endometriosis during the study.
  • Must have a normal breast examination. If 40 years or older, must have had a mammogram or breast MRI in the last 12 months with no significant issues.
  • Must agree not to participate in another study while in this one.
  • Must be able and willing to follow all study procedures, including attending study visits, using only the provided pain medication, stopping hormone treatment for endometriosis-related pain, completing electronic diary entries, and undergoing tests like ultrasound and ECG.
  • Must agree to use two forms of non-hormonal contraception during the study.
  • Must not plan to move away during the study period.
  • Must be willing and able to provide signed consent to participate in the study.
  • Must have a negative pregnancy test before starting the study.
  • Must have shown compliance with at least 75% of electronic diary entries during the screening period.
  • Must have taken only the study-provided rescue medication for pain control during the screening period.

Who cannot join the trial?

4 criteria

  • Patients who are not experiencing endometriosis-related pain cannot participate.
  • Only females are eligible to participate in this study.
  • Males are not eligible to participate in this study.
  • Individuals who are considered part of a vulnerable population are not eligible. This means people who might need special protection or care.
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Investigated drugs

OG-6219 is a medication being tested to see if it can help reduce pain associated with endometriosis, a condition where tissue similar to the lining inside the uterus grows outside of it, causing pain. This study is looking at how well OG-6219 works in easing pelvic pain that women with endometriosis often experience. The medication is being tested in different amounts to find out which one works best. The study also checks if OG-6219 is safe to use and if it causes any side effects. Participants in the trial will take OG-6219 and report their pain levels to help researchers understand its effectiveness.

What is already known about the treatment

OG-6219 – OG-6219 is an investigational medication currently being studied in a clinical trial for its potential to alleviate pain associated with endometriosis, a condition where tissue similar to the lining inside the uterus grows outside of it, causing pain. This medication is administered orally in different dose levels to evaluate its effectiveness and safety in reducing pelvic pain in women aged 18 to 49. The trial aims to determine how well OG-6219 works compared to a placebo by measuring pain reduction using a numeric scale. While the exact molecular mechanism of OG-6219 is not detailed, it is being explored for its potential therapeutic benefits in managing endometriosis-related pain.

Investigated diseases

Endometriosis – Endometriosis is a condition where tissue similar to the lining inside the uterus, called endometrium, starts to grow outside the uterus. This misplaced tissue can be found on the ovaries, fallopian tubes, and the outer surface of the uterus, as well as other organs within the pelvis. The disease progresses as these endometrial-like tissues continue to thicken, break down, and bleed with each menstrual cycle, but they have no way to exit the body. This can lead to inflammation, scar tissue formation, and adhesions, which are bands of fibrous tissue that can cause pelvic tissues and organs to stick to each other. Over time, this can result in chronic pain, especially during menstruation, and may also lead to fertility problems. The severity of symptoms can vary widely among individuals, with some experiencing mild discomfort and others suffering from debilitating pain.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IITrial ID2022-501310-57-00Protocol codeOG-6219-P001Estimated enrolment380 patientsSponsorOrganon LLC

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On this site, “treatment” means an investigational medicine being studied in a clinical trial. Its safety and efficacy for the use being studied have not yet been confirmed, some participants may receive a placebo or a comparator medicine, and taking part does not guarantee any health benefit. The decision to take part is made by the doctor at the research site. This site is for information only and does not replace medical advice.

This service is not affiliated with the European Commission, the EMA, or the official CTIS system. Most information comes from publicly available international clinical-trial registries, supplemented by data from academic sites, national regulators and commercial sponsors. On this site, “treatment” and “therapy” mean a medicine being tested in a clinical trial. Its safety and effectiveness in the use being studied are not yet confirmed, some participants may receive a placebo or a comparator, and taking part does not guarantee a health benefit. The doctor at the research site decides who can take part. This site provides information, not medical advice. Certain content and visual elements on this website have been generated or enhanced using artificial intelligence (AI).