Phase 2
N=354
A Study to Investigate Efficacy and Safety of OG-6219 BID in 3 Dose Levels Compared With Placebo in Participants Aged 18 to 49 With Moderate to Severe Endometriosis-related Pain
Endometriosis
Bottom Line
View on ClinicalTrials.gov: NCT05560646 ↗Enrolled (actual)
354
Serious AEs
0.3%
Results posted
May 2026
Primary outcome: Primary: Change From Baseline Cycle in Mean Overall Pelvic Pain Score at Treatment Cycle 3 — -1.8; -1.6; -1.5; -2.0 score on a scale
Study Design & Population
- Study type
- Interventional
- Phase
- Phase 2
- Interventions
- OG-6219 (Drug); Placebo (Drug)
- Age
- Adult · 18+ yrs
- Sex
- Female
- Sponsor
- Organon and Co
- Primary completion
- May 2025
Outcome Measures
| Outcome | Result | p-value |
|---|---|---|
| PRIMARY Change From Baseline Cycle in Mean Overall Pelvic Pain Score at Treatment Cycle 3 |
-1.8; -1.6; -1.5; -2.0 | — |
| PRIMARY Percentage of Participants With Treatment-Emergent Adverse Events (TEAEs) and Treatment-Emergent Serious Adverse Events (TESAEs) |
51.1; 52.3; 51.1; 55.1; 0; 1.1 | — |
| PRIMARY Percentage of Participants With Treatment-Emergent Adverse Events Leading to Study Treatment Discontinuation |
3.4; 2.3; 1.1; 5.6 | — |
| SECONDARY Change From Baseline Cycle in Mean Dysmenorrhea Score at Treatment Cycle 3 |
-1.9; -1.5; -1.5; -1.9 | — |
| SECONDARY Change From Baseline Cycle in Mean Non-Menstrual Pelvic Pain Score at Treatment Cycle 3 |
-1.9; -1.6; -1.5; -2.1 | — |
| SECONDARY Change From Baseline Cycle in Mean Dyspareunia Score at Treatment Cycle 3 |
-1.5; -1.3; -1.5; -1.2 | — |
| SECONDARY Change From Baseline Cycle in Mean Number of Rescue Medication Tablets Used for Endometriosis-Related Pain at Treatment Cycles 1, 2 and 3 |
-0.2; -0.2; -0.2; -0.2; -0.2; -0.2 | — |
| SECONDARY Change From Baseline Cycle in Percentage of Days With Participants Used Rescue Medication for Endometriosis-Related Pain at Treatment Cycles 1, 2 and 3 |
-10.7; -8.7; -9.2; -14.1; -15.6; -9.8 | — |
| SECONDARY Change From Start of Treatment Cycle 1 in Participants With Patient Global Impression of Severity (PGI-S) to Start of Treatment Cycle 2, End of Treatment Cycles 2 and 3 |
4; 3; 6; 7; 23; 17 | — |
| SECONDARY Percentage of Participants With Any Improvement on the Patient Global Impression of Change (PGI-C) at Start of Treatment Cycle 2 and End of Treatment Cycles 2 and 3 |
56.8; 60.2; 51.1; 61.8; 62.5; 64.8 | — |
| SECONDARY Change From Baseline Cycle in Endometriosis Health Profile-30 (EHP-30) Domains Score at Treatment Cycle 3 |
-21.04; -20.96; -19.75; -24.62; -23.93; -22.75 | — |
| SECONDARY Mean Change From Screening in C-Telopeptide of Type I Collagen (CTX) and Procollagen Type I N-Terminal Propeptide (P1NP) at End of Treatment Cycle 3 |
0.0; 0.0; 0.0; 0.0; 2.3; -1.7 | — |
| SECONDARY Mean Change From Screening in Bone-Specific Alkaline Phosphatase (BSAP) and Osteocalcin at End of Treatment Cycle 3 |
0.3; -0.7; -0.1; -0.5; 0.8; -0.8 | — |
| SECONDARY Mean Change From Screening in N-Telopeptide of Type I Collagen (NTX) at End of Treatment Cycle 3 |
29.8; 28.2; 1.7; 9.0 | — |
| SECONDARY Mean Change From Screening in Tartrate-Resistant Acid Phosphatase 5b (TRAP5b) at End of Treatment Cycle 3 |
-0.1; -0.4; -0.3; -0.4 | — |
| SECONDARY Number of Participants With Clinically Significant Laboratory Abnormalities |
0; 0; 1; 0; 0; 0 | — |
| SECONDARY Mean Change From Baseline Cycle in Sum of Days on Period at Treatment Cycles 1, 2 and 3 |
-0.1; -0.3; -0.2; 0.2; -0.3; -0.2 | — |
| SECONDARY Number of Participants With Clinically Significant Electrocardiogram (ECG) Parameters Abnormalities |
2; 1; 0; 2; 1; 0 | — |
| SECONDARY Mean Change From Screening in Luteinizing Hormone (LH) and Follicle Stimulating Hormone (FSH) at 7 Days After Urine Luteinizing Hormone Surge and End of Treatment Cycles 2 and 3 |
-0.0; -0.6; -1.5; 2.3; -0.1; -0.6 | — |
| SECONDARY Mean Change From Screening in Estrone (E1) at 7 Days After Urine Luteinizing Hormone Surge and End of Treatment Cycles 2 and 3 |
-7.8; 41.5; 25.6; 51.9; -28.1; 50.5 | — |
| SECONDARY Mean Change From Screening in Progesterone, Testosterone and Dehydroepiandrosterone (DHEA) at 7 Days After Urine Luteinizing Hormone Surge and End of Treatment Cycles 2 and 3 |
11.5; 14.8; 17.7; 11.9; -0.8; 0.2 | — |
| SECONDARY Mean Change From Screening in Free Testosterone and Estradiol (E2) at 7 Days After Urine Luteinizing Hormone Surge and End of Treatment Cycles 2 and 3 |
0.1; 0.8; 0.4; 1.8; 0.1; 0.4 | — |
| SECONDARY Mean Change From Screening in Dehydroepiandrosterone Sulfate (DHEAS) at 7 Days After Urine Luteinizing Hormone Surge and End of Treatment Cycles 2 and 3 |
0.2; 0.1; 0.5; 0.5; 0.2; -0.0 | — |
| SECONDARY Plasma Concentrations of OG-6219 and FOR-1011 |
0.977; 8.035; 5.360; 190.754; 356.706; 610.430 | — |
| SECONDARY Maximum Concentration (Cmax) of OG-6219 and FOR-1011 |
328.000; 344.500; 227.000; 560.000; 142.000; 149.000 | — |
| SECONDARY Time Taken to Reach the Maximum Concentration (Tmax) of OG-6219 and FOR-1011 |
2.0000; 2.4900; 1.2500; 2.0100; 2.5000; 3.5100 | — |
| SECONDARY Area Under the Plasma Concentration-Time Curve During a Dosing Interval (AUCtau) of OG-6219 and FOR-1011 |
1049.827; 1838.584; 1259.562; 3554.051; 679.947; 993.293 | — |
Summary
The purpose of this global Phase 2 study is to determine the efficacy, safety, and tolerability of 3 dose levels of OG-6219 in pre-menopausal women between 18 and 49 years of age (inclusive), who have moderate to severe endometriosis-related pain.
Eligibility Criteria
Inclusion Criteria
- Pre-menopausal females of age 18 to 49 years old (inclusive) at the time of signing Informed Consent (V1).
- Surgically (laparoscopy or laparotomy) diagnosed with endometriosis
- Moderate to severe endometriosis-related pelvic pain
- Regular menstrual cycles
- Is not expected to undergo a planned gynecological surgery or other surgical procedures for treatment of endometriosis during study participation.
- Normal breast exam at V1. In participants of ≥40 years mammography or contrast-enhanced breast MRI performed within the last 12 months prior to Screening (V1) without clinically significant abnormal findings.
- Agree not to participate in another interventional study while participating in the present study.
- Able and willing to adhere to study procedures, including
- agree to use 2 forms of non-hormonal contraception throughout the study
- Must be willing and able to provide signed informed consent before any study-related activities
- Has demonstrated compliance with ≥75% of eDiary entries
- Has a negative pregnancy test
Exclusion Criteria
- Surgical history of hysterectomy and/or bilateral oophorectomy
- Chronic pelvic and/or non-pelvic pain not caused by endometriosis that requires chronic analgesic or other chronic therapy
- Undiagnosed (unexplained), abnormal vaginal bleeding not associated with endometriosis within the past 6 months before screening.
- Presence of high-risk human papillomavirus (HPV).
- Has an active sexually transmitted infection (STI) (eg, gonorrhea, chlamydia, or trichomonas).
- Intends to become pregnant or breast feed during study participation or has a known or suspected pregnancy.
- History of malignancy (except for basal cell or squamous cell skin cancer) before signing informed consent.
- History of family history of hereditary abnormal hemoglobin or an enzyme deficiency that can result in methemoglobinemia.
- Has a medical condition associated with hemolytic anemia
- Known human immunodeficiency virus infection, and/or acute or active, recurrent/relapsing, or chronic infection (eg, hepatitis A, B, or C virus)
- Has a clinically significant abnormal ECG or QT interval prolongation
- Used any medication that is either a sensitive substrate, moderate, or strong inhibitor or inducer of CYP3A4 within 30 days or 10 half-lives (whichever is longer) prior to the planned first day of dosing.
Data sourced from ClinicalTrials.gov (NCT05560646). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication.