- If they were of childbearing potential must have: had a negative pregnancy test with a sensitivity of at least 25 mIU/mL within 10 to 14 days and again within 24 hours prior to starting Cycle 1 of lenalidomide; either agreed to practice true abstinence, when this was in line with the preferred and usual lifestyle of the participant. (Periodic abstinence [eg, calendar, ovulation, symptothermal, post-ovulation methods] and withdrawal were not acceptable methods of contraception.) OR begun 2 reliable methods of birth control (1 highly effective method and 1 additional effective method) at the same time, at least 28 days before starting study treatment through 90 days after the last dose of study treatment; and agreed to ongoing pregnancy testing AND must have also adhered to the guidelines of the RevAssist program (US participants), RevAid program (Canadian participants), iAccess program (Australian participants), RevMate program (Japanese participants) or The Lenalidomide Pregnancy Risk Minimisation Plan as outlined in the Study Manual (all other participants who were not using commercial supplies).