- A female subject is eligible to participate if she is of: Non-childbearing potential is defined as pre-menopausal females with a documented tubal ligation or hysterectomy; or postmenopausal defined as 12 months of spontaneous amenorrhea. In questionable cases a blood sample with simultaneous follicle stimulating hormone (FSH) greater than 40 MlU/ml and estradiol less than 40 pg/ml (less than 147 pmol/L) is confirmatory. Females on hormone replacement therapy (HRT) and whose menopausal status is in doubt will not be eligible for the study.