METHODS: Asian women received dienogest (2 mg/daily) and were followed for 24 months. The effectiveness of dienogest to improve HRQoL and endometriosis-associated pelvic pain (EAPP) was assessed by patient-reported outcomes. HRQoL, especially the "pain" domain as primary endpoint, was evaluated with the Endometriosis Health Profile-30 (EHP-30) questionnaire. The numeric rating scale served to determine changes in the severity of EAPP. Within the presented interim analysis (data cut-off: 2017-11-27), the mean changes in EHP-30 and EAPP scores from baseline to 6 months upon availability of the data were evaluated. Treatment-emergent adverse events (TEAEs) and bleeding profiles were documented.

RESULTS: Dienogest therapy decreased EHP-30 scores in all assessed domains (score 0-100, lower scores indicate better HRQoL). Primarily, the "pain" domain was improved in 78.4% of patients. EAPP was reduced (score 0-10, lower scores reflect less pain), highlighted by a mean reduction of the pain score by - 4.5 points. Patients with a higher EAPP score at baseline had an increased response to dienogest (- 6.2 points mean change) compared to patients with low baseline EAPP severity (- 1.4 points mean change). Both surgically and clinically diagnosed patients described comparable pain reduction, as well as women with or without prior treatment. Drug-related TEAEs were documented for 31.5% of patients, with amenorrhoea (5.9%) and metrorrhagia (5.1%) being the most common events. The bleeding pattern was changed upon dienogest, characterized by decreased normal bleeding (84.2 to 28.8%) and increased amenorrhea (3.2 to 42.9%) at 6 months.

CONCLUSION: The data indicate an amelioration of HRQoL and EAPP upon dienogest therapy. No new safety signals were observed. Therefore, its use as first-line therapy for long-term management of debilitating and chronic endometriosis-associated pain represents an interesting option that remains to be further investigated.