- Women of child-bearing potential must have a negative serum or urine pregnancy test with a sensitivity of at least 50 milli-international units per milliliter (mIU)mL) within 10 days and again within 24 hours prior to beginning study treatment. Participants of childbearing potential must practice recommended contraception. Should a woman become pregnant or suspect she is pregnant while participating in this study, she should inform her treating physician immediately. Breastfeeding mothers must agree to discontinue nursing if the mother is treated with selinexor.