- Subjects who are women of childbearing potential must have a negative urine pregnancy test at screening and must be practicing an adequate, medically acceptable method of birth control for at least 30 days before Day 0 and at least 6 months after the last study drug administration. Acceptable methods of birth control include intrauterine device (IUD); oral, transdermal, implanted or injected hormonal contraceptives (must have been initiated at least 1 month before entering the study); tubal ligation; abstinence and barrier methods with spermicide. Otherwise, if not of childbearing potential, subjects must: have a sterile or vasectomized partner; have had a hysterectomy, a bilateral oophorectomy or be clinically diagnosed infertile; or be in a menopausal state for at least a year.