Cluster 384: surgically childbearing potential abstain heterosexual activity sterile sterilized study subjects Cluster 925: bilateral potential females childbearing postmenopausal surgically hysterectomy oophorectomy sterile tubal Cluster 2193: sterile surgically documented postmenopausal effective month contraception hysterectomy screening post Cluster 2458: women childbearing potential amenorrhea possibly amenorrheic bilateral months suppression antiestrogens