Primary Outcome Measures:
- The percent of subjects in each endometrial biopsy diagnostic category summarized using SPRM Classification System. [ Time Frame: Throughout Study ] [ Designated as safety issue: Yes ]
- The percentage of subjects in each endometrial biopsy diagnostic category summarized using SPRM Classification System [ Time Frame: Months 3,6 ] [ Designated as safety issue: Yes ]
- Change from baseline in endometrial thickness (mm) as measured by transvaginal ultrasound. [ Time Frame: Months 3,6 ] [ Designated as safety issue: Yes ]
Secondary Outcome Measures:
- Frequency and amount of vaginal bleeding assessed via daily diary. [ Time Frame: Throughout study ] [ Designated as safety issue: No ]
- Frequency and severity of hot flushes assessed via daily diary. [ Time Frame: Throughout study ] [ Designated as safety issue: No ]
- Mean change from baseline in endocrine determinations. [ Time Frame: Months 2,4,and 6 ] [ Designated as safety issue: No ]
- Global efficacy question [ Time Frame: Month 6 ] [ Designated as safety issue: No ]
The objective of this study is to determine the long-term safety of asoprisnil 10 mg (2-5mg tablets) when taken with Premarin® 0.625 mg, by postmenopausal women, for 6 months after an initial 12 weeks in Study M00-198. Pharmacodynamic effects to be assessed include uterine bleeding pattern, endometrial biopsy results, and endometrial thickness. Safety assessments will include clinical laboratory results, physical examination with vital signs, pelvic and breast examinations, ultrasound results, and adverse events.