- Female subjects of childbearing potential who are currently sexually active must be using a medically acceptable form of birth control for at least one month prior to screening (three months on oral contraceptives), e.g., oral or patch contraceptives, intrauterine device, Nuvaring, Depo-Provera, or double-barrier and have a negative pregnancy test at screening/treatment period. Female subjects of non-childbearing potential must be amenorrheic for at least two years or had a hysterectomy and/or bilateral oophorectomy.