A Phase 3 interventional study of KLH-2109 and Leuprorelin acetate in Endometriosis, sponsored by Kissei Pharmaceutical Co., Ltd.. Active, not recruiting at 1 site in Japan. Open to female participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-03-02.
Sponsored by Kissei Pharmaceutical Co., Ltd. · Phase 3, Interventional, and Treatment
To verify the non-inferiority of KLH-2109 to leuprorelin acetate in a double-blind manner in terms of efficacy in endometriosis patients with pelvic pain.
Premenopausal women aged 18 years or older (at the time of consent) with endometriosis who meet any of the following inclusion criteria.:
Exclusion Criteria:
Oral administration
Drug: KLH-2109
Subcutaneous administration
Drug: Leuprorelin acetate
\- KLH-2109 tablet: Oral administration \- Leuprorelin acetate placebo: Subcutaneous administration
\- KLH-2109 placebo tablet: Oral administration \- Leuprorelin acetate: Subcutaneous administration
Change from baseline in the maximum NRS score for pelvic pain during 28 days prior to 12 weeks of the investigational product treatment
NRS score for pelvic pain: The NRS score for pelvic pain is an integer scale of 0 to 10 in which the worst daily pain associated with endometriosis is scored as 0 for "no pain" and 10 for "the worst pain imaginable."
Time frame: 12 weeks
Change from baseline in and actual values of the maximum NRS score for pelvic pain every 28 days
The NRS score for pelvic pain is an integer scale of 0 to 10 in which the worst daily pain associated with endometriosis will be scored as 0 for "no pain" and 10 for "the worst pain imaginable."
Time frame: Up to 24 weeks
Change from baseline in and actual values of the maximum severity score for pelvic pain every 28 days
The severity of pelvic pain will be assessed on a five-point scale, based on the most severe pain experienced during the day: as score 0 for "None: No pain", score 1 for "Very mild: Not bothersome, score 2 "Mild: Concerned but tolerable (not requiring analgesics), score 3 for "Moderate: Unbearable (requiring analgesics), and score 4 for "Severe: Intolerable despite the use of analgesics.
Time frame: Up to 24 weeks
Change from baseline in and actual values of severity score for temporary pain at each evaluation time point
Pain in bowel movement will be assessed on a five-point scale: as score 0 for "None: No pain", score 1 for "Very mild: Not bothersome", score 2 "Mild: Concerned but tolerable", score 3 for "Moderate: Unbearable to continuously receive stimulation causing the pain", and score 4 for "Severe: Intolerable unless stimulation causing the pain is immediately discontinued". Pain during a pelvic examination will be assessed on a four-point scale: as score 0 for "None: No findings", score 1 for "Mild: Pelvic tenderness", score 2 for "Moderate: Between Mild and Severe", and score 3 for "Severe: Severe pelvic tenderness". Dyspareunia will be assessed on a five-point scale: as score 0 for "None: No pain", score 1 for "Very mild: Not bothersome", score 2 for "Mild: Feeling pain but tolerable", score 3 for "Moderate: Severe pain and discontinuation due to pain", and score 4 for "Severe: Unbearable severe pain and avoidance of sexual intercourse from the beginning".
Time frame: Up to 24 weeks
Change from baseline in and actual values of severity score of objective findings at each evaluation time point
* The severity of the induration of the pouch of Douglas will be assessed on a four-point scale: as score 0 for "None: No findings", score 1 for "Mild: Presence of a small finger-sized induration", score 2 for "Moderate: Between Mild and Severe", and score 3 for "Complete occlusion of the pouch of Douglas with no elasticity". * The severity of the limitation of uterine mobility will be assessed on a four-point scale: as score 0 for "None: No findings", score 1 for "Mild: Limited mobility ", score 2 for "Moderate: Severely limited mobility", and score 3 for "Severely limited mobility, no movement at all".
Time frame: Up to 24 weeks
Percent change from baseline in and actual values of ovarian chocolate cyst volume at each evaluation time point
The presence or absence of ovarian chocolate cyst in both ovaries will be determined by ultrasonography (transvaginal, transabdominal, or transrectal) and the long and short axes of all ovarian chocolate cysts (unit, mm) will be measured.
Time frame: Up to 24 weeks
Change from baseline in and actual values of EHP-30 domain score at each evaluation time point
The EHP-30 is a questionnaire rating scale of 30 items related to QOL in patients with endometriosis on a 5-point scale: "Never", "rarely", "sometimes", "often" and "always". The subjects themselves will evaluate their QOL for the prior month using the EHP-30 questionnaire form and record the results of their assessment in the questionnaire form.
Time frame: Up to 24 weeks
Incidence of adverse events and treatment-related adverse events
Time frame: Up to 24 weeks
Percent change from baseline in bone mineral density at each evaluation time point
Time frame: Up to 24 weeks
Change from baseline in T-score at each evaluation time point
The "T-score" is an important indicator used in bone density tests. It shows how much an individual's bone density deviates from the average value of young adults (YAM: Young Adult Mean) in terms of standard deviations (SD). Specifically, it is evaluated as follows: * -1.0 or above: Normal * Between -1.0 and -2.5: Low bone mass (osteopenia) * -2.5 or below: Osteoporosis
Time frame: Up to 24 weeks
Plan to share: Yes — * The Individual Patient Data (IPD) are available upon reasonable request and with permission of Kissei Pharmaceutical Co., Ltd. * For a data sharing request for IPD, please contact Kissei Pharmaceutical at rinsyousiken@pharm.kissei.co.jp.
Supporting information: Study protocol, Sap
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Kissei Pharmaceutical Co., Ltd.