- Female participants of childbearing potential must have a negative serum pregnancy within 72 hours prior to receiving the first dose of study medication. They should also be willing to use 2 methods of birth control or be surgically sterile, or abstain from heterosexual activity for the course of the study through 120 days after the last dose of study medication. Refer to section 4.4 for more details. All female subjects of childbearing potential must agree to take appropriate precautions to avoid pregnancy (with at least 99% certainty) from screening through 120 days after the last dose of study treatment. Permitted methods that are at least 99% effective in preventing pregnancy. See Appendix A Note: Abstinence is acceptable if this is the usual lifestyle and preferred contraception for the subject.