RE-REGISTRATION ELIGIBILITY CRITERIA (STEP ): \r\n* Women of childbearing potential:\r\n** Must have a negative serum or urine pregnancy test within hours prior to re-registration\r\n** Must either commit to complete abstinence from heterosexual contact or begin TWO acceptable methods of birth control, one highly effective method and one additional effective (barrier) method, AT THE SAME TIME, before starting pomalidomide\r\n** Must agree to ongoing pregnancy testing\r\n** Must agree to not become pregnant or breast feed a child during treatment on this protocol\r\n* Men must practice complete abstinence or agree to use a condom during sexual contact with a female of childbearing potential, even if they have had a successful vasectomy\r\n* Note: All participants must be counseled at a minimum of every days about pregnancy precautions and risks of fetal exposure Females of childbearing potential (FCBP) must have a negative serum or urine pregnancy test with a sensitivity of at least mIU/mL within days and again within hours prior to starting cycle of pomalidomide 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 days before she starts taking pomalidomide; 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; all subjects must be counseled on day of each cycle (or at a minimum of every days) and at drug discontinuation about pregnancy precautions and risks of fetal exposure Women of childbearing potential must follow pregnancy testing requirements as outlined in the Revlimid Risk Evaluation and Mitigation Strategy (REMS) program material; this is defined as either commit to continued abstinence from heterosexual intercourse or begin TWO acceptable methods of contraception (one highly effective method and one additional effective method (AT THE SAME TIME) at least days prior to the start of lenalidomide, for the duration of study participation, and for days following the last doses of brentuximab vedotin and lenalidomide; women of childbearing potential must also agree to ongoing pregnancy testing; men must agree to use a latex condom during sexual contact with a woman of childbearing potential even if they have had a successful vasectomy; all patients must be counseled at a minimum of every days about pregnancy precautions and risks of fetal exposure; should a woman become pregnant or suspect she is pregnant while participating in this study, she must inform her treating physician immediately Females of childbearing potential (FCBP) must have a negative serum or urine pregnancy test with a sensitivity of at least mIU/mL within days prior to and again within hours of starting lenalidomide 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 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; all patients must be counseled at a minimum of every days about pregnancy precautions and risks of fetal exposure Female of child bearing potential (FCBP) must have a negative serum or urine pregnancy test with a sensitivity of at least mIU/mL or equivalent units of human chorionic gonadotropin (HCG) within days prior to and again within hours of starting lenalidomide and study drug and must either commit to continue 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 weeks before she starts taking lenalidomide through weeks after the last dose of lenalidomide and half-lives after elotuzumab plus days (duration of ovulatory cycle) for a total of days post-last dose of elotuzumab; FCBP must also agree to ongoing pregnancy testing during the entire duration of treatment; males must agree to use a latex or synthetic condom during sexual contact with a FCBP even if they have had a vasectomy from the time of signing the informed consent form through days after the last dose of lenalidomide and half-lives of elotuzumab plus days (duration of sperm turnover) for a total of days post-last dose of elotuzumab; these same patients must not donate sperm; all patients must be counseled at a minimum of every days about pregnancy precautions and risks of fetal exposure; all patients prior to taking lenalidomide, must be registered in and must comply with all requirements of the lenalidomide Risk Evaluation and Mitigation Strategies (REMS) program Females of childbearing potential (FCBP) must have a negative serum or urine pregnancy test with a sensitivity of at least mIU/mL within days prior to and again within hours before starting lenalidomide 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 days before she starts taking lenalidomide; females of reproductive potential must adhere to the scheduled pregnancy testing as required in the Revlimid REMS program; men must agree to use a latex condom during sexual contact with a FCBP even if they have had a vasectomy; all subjects must be counseled at a minimum of every days about pregnancy precautions and risks of fetal exposure Females of childbearing potential (FCBP) must have a negative serum or urine pregnancy test with a sensitivity of at least mIU/mL within days prior to and again within hours before starting pomalidomide 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 days before she starts taking pomalidomide; 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 vasectomy; all subjects must be counseled at a minimum of every days about pregnancy precautions and risks of fetal exposure Women of childbearing potential must follow pregnancy testing requirements as outlined in the Revlimid Risk Evaluation and Mitigation Strategy (REMS) program material; this is defined as either committing to continued abstinence from heterosexual intercourse or beginning TWO acceptable methods of contraception (one highly effective method and one additional effective method AT THE SAME TIME) at least days prior to the start of lenalidomide, for the duration of study participation, and for days following the last dose of lenalidomide; women of childbearing potential must also agree to ongoing pregnancy testing Females of childbearing potential (FCBP) must have a negative serum or urine pregnancy test with a sensitivity of at least mIU/mL within days prior to and again within hours of starting pomalidomide 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 days before she starts taking pomalidomide; FCBP must also agree to ongoing pregnancy testing Females of childbearing potential (FCBP) must have a negative serum or urine pregnancy test with a sensitivity of at least mIU/mL within days prior to and again within hours before starting pomalidomide 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 days before she starts taking pomalidomide; 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 vasectomy; all subjects must be counseled at a minimum of every days about pregnancy precautions and risks of fetal exposure Females of childbearing potential (FCBP) must have a negative serum or urine pregnancy test with a sensitivity of at least mIU/mL within - days prior to and again within hours of starting lenalidomide 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 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. All patients must be counseled at a minimum of every days about pregnancy precautions and risks of fetal exposure. Woman with child bearing potential 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 weeks before she starts taking lenalidomide Pregnant and nursing subjects may not be enrolled and pregnancy must be avoided; women of child-bearing potentialdefined as a sexually active woman who has not undergone hysterectomy and who has had menses any time within the preceding monthsmust have a negative serum or urine pregnancy test within days prior to registration; women and men of childbearing potential must either commit to continued abstinence from heterosexual intercourse or commit to two acceptable methods of birth controlone highly effective method (e.g., IUD, oral or non-oral hormonal contraceptive, tubal ligation or partners vasectomy) and one additional effective method (e.g., latex condom, diaphragm or cervical cap) at the same time from the time of screening through final Treatment Response Assessment\r\n* NOTE: should a woman become pregnant or suspect she is pregnant while she or her partner is participating in this study, the subject should inform their treating phy-sician immediately\r\n* NOTE: the effects of decitabine on the developing human fetus are unknown but it is a know teratogen in mammals (mice) Women of childbearing potential must follow pregnancy testing requirements; this is defined as either commit to continued abstinence from heterosexual intercourse or begin TWO acceptable methods of contraception (one highly effective method and one additional effective method AT THE SAME TIME at least days prior to the start of lenalidomide, for the duration of study participation, and for days following the last doses of brentuximab vedotin and lenalidomide; women of childbearing potential must also agree to ongoing pregnancy testing; men must agree to use a latex condom during sexual contact with a woman of childbearing potential even if they have had a successful vasectomy; all patients must be counseled at a minimum of every days about pregnancy precautions and risks of fetal exposure; should a woman become pregnant or suspect she is pregnant while participating in this study, she must inform her treating physician immediately Females of childbearing potential (FCBP) must have a negative serum or urine pregnancy test with a sensitivity of at least mIU/mL within - days and again within hours prior to starting cycle of lenalidomide 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 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, all patients must be counseled at a minimum of every days about pregnancy precautions and risks of fetal exposure Females of childbearing potential (FCBP) must have a negative serum or urine pregnancy test with a sensitivity of at least mIU/mL within - days prior to and again within hours of starting pomalidomide or MLN 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 days before she starts taking pomalidomide or MLN through days after the last dose of study drug; 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 vasectomy from the time of signing the informed consent form through days after the last dose of study drug; all patients must be counseled at a minimum of every days about pregnancy precautions and risks of fetal exposure Female who is able to become pregnant must have a negative pregnancy test with a sensitivity of at least mIU/mL within - days prior to and again within hours of starting pomalidomide; female who is able to become pregnant must either commit to continued abstinence from heterosexual intercourse or begin two acceptable methods of birth control, one highly effective and one additional effective method at the same time; female who is able to become pregnant must agree to ongoing pregnancy testing; men must agree to use a latex condom during sexual contact with female who is able to become pregnant even if they had vasectomy for the duration of study participation, and days after completion of pomalidomide administration; all patients must be counseled at a minimum of every days about pregnancy precautions and risks of fetal exposure while taking pomalidomide; should a woman become pregnant or suspect she is pregnant while she or her partner is participating in this study, she should inform her treating physician immediately Females of child bearing potential (FCBP) must have a negative serum or urine pregnancy test with a sensitivity of at least mIU/mL within - days prior to, and again within hours of starting pomalidomide 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 days before she starts taking pomalidomide. 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 vasectomy. All patients must be counseled at a minimum of every days about pregnancy precautions and risks of fetal exposure. Risks of Fetal Exposure, Pregnancy Testing Guidelines and Acceptable Birth Control Methods,and Education and Counseling Guidance must be followed per protocol Females of childbearing potential (FCBP) must have a negative serum or urine pregnancy test with a sensitivity of at least mIU/mL within - days and again within hours prior to starting cycle of pomalidomide 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 days before she starts taking pomalidomide; FCBP must also agree to ongoing pregnancy testing and follow pregnancy testing requirements as outlined in the POMALYST REMS program; men must agree to use a latex condom during sexual contact with a FCBP even if they have had a successful vasectomy; all patients must be counseled at a minimum of every days about pregnancy precautions and risks of fetal exposure Agree to adhere to methods of contraception and other fertility control measures as prescribed by the protocol\r\n* Women of child-bearing potential and men must agree to use effective forms of contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation; should a woman become pregnant or suspect she is pregnant while she or her partner is participating in this study, she should inform her treating physician immediately\r\n* Female subjects\r\n** Females of childbearing potential (FCBP) must have a negative serum or urine pregnancy test with a sensitivity of at least mIU/mL within - days prior to and again within hours of starting pomalidomide 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 days before she starts taking pomalidomide; 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 vasectomy; all patients must be counseled days about pregnancy precautions and risks of fetal exposure through the POMALYST Risk Evaluation and Mitigation Strategy (REMS) program\r\n* Male subjects\r\n** Must agree to use a latex condom during sexual contact with females of childbearing potential while participating in the study and for at least days following discontinuation of study drug even if he has undergone a successful vasectomy\r\n** Will be warned that sharing study drug is prohibited and will be counseled about pregnancy precautions and potential risks of fetal exposure\r\n** Must agree to abstain from donating blood, semen, or sperm during study participation and for at least days after discontinuation of study drug\r\n** Must agree that if a pregnancy or a positive pregnancy test does occur in a study subject or the partner of a male study subject during study participation, study drug must be immediately discontinued\r\n* Patients must agree to not share study drug with anyone during participation in the study Female of childbearing potential must have a negative serum or urinary pregnancy test with a sensitivity of at least mIU/mL - days prior to and again within hours of prescribing lenalidomide for Cycle and must either commit to continued abstinence or begin TWO acceptable methods of birth control, one highly effective method and one additional effective method at the same time, at least days prior to taking lenalidomide. Also agree to ongoing pregnancy testing. Female patients of childbearing potential (including those who commit to complete abstinence) are not eligible unless they agree to ongoing pregnancy testing and counseling every days about pregnancy precautions and risks of fetal exposure Females of childbearing potential (FCBP) must have a negative serum or urine pregnancy test with a sensitivity of at least mIU/mL - days prior to and again within hours of starting lenalidomide 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 weeks before she starts taking lenalidomide. FCBP must also agree to ongoing pregnancy testing. Men must agree not to father a child and agree to use a condom if his partner is of child bearing potential. All patients must be counseled at a minimum of every days about pregnancy precautions and risks of fetal exposure. Females of childbearing potential (FCBP) must have a negative serum or urine pregnancy test with a sensitivity of at least mIU/mL within - days prior to and again within hours of starting Revlimid 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 days before she starts taking Revlimid; 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; all patients must be counseled at a minimum of every days about pregnancy precautions and risks of fetal exposure Females of childbearing potential (FCBP) must have a negative serum or urine pregnancy test with a sensitivity of at least mIU/mL within days and again within hours prior to starting cycle of lenalidomide; further, they 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 days before starting 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; all patients must be counseled at a minimum of every days about pregnancy precautions and risks of fetal exposure Woman with child bearing potential 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 Female subjects must be postmenopausal for at least year before the screening visit or surgically sterilized; if females are of childbearing potential, they must:\r\n* Have a negative serum pregnancy test with a sensitivity of at least mIU/mL at study screening; additional mandatory pregnancy tests will be performed as specified; compliance with ongoing pregnancy testing is required for study participation\r\n* 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 the time of signing the informed consent through days after the last dose of any study medication FCBP must have a negative serum or urine pregnancy test with a sensitivity of at least mlU/mL within - days prior to and again within hours of starting lenalidomide 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 days before she starts taking lenalidomide