- Women of childbearing potential (WCBP) must agree to practice complete abstinence from heterosexual intercourse or to use two methods of contraception beginning 4 weeks prior to the start of study drug (Day 1) while on study drug (including dose interruptions) and 4 weeks after the last dose of study drug. The two methods of contraception must include one highly effective method (i.e. intrauterine device, hormonal [birth control pills, injections, or implants only if used in conjunction with a low-dose (81 mg/day) aspirin regimen], tubal ligation, partner's vasectomy) and one additional effective (barrier) method (i.e. latex condom, diaphragm, cervical cap). If a hormonal method (birth control pills, injections or implants) or IUD is not medically possible for the subject, two of the barrier methods will be acceptable.