 8. Females of childbearing potential FCBP must have a negative serum or urine pregnancy test with a sensitivity of at least 50 mIUmL within 10 - 14 days and again within 24 hours prior to prescribing lenalidomide for Cycle 1 prescriptions must be filled within 7 days as required by RevAssist and must either commit to continued abstinence from heterosexual intercourse or begin TWO acceptable methods of birth control, one highly effective method and one additional effective method AT THE SAME TIME, at least 28 days before she starts taking lenalidomide. FCBP must also agree to ongoing pregnancy testing. Men must agree to use a latex condom during sexual contact with a FCBP even if they have had a successful vasectomy. See Appendix E: Risks of Fetal Exposure, Pregnancy Testing Guidelines and Acceptable Birth Control Methods. 