Adverse events

This is a prospective, two-arm phase I randomized trial. Patients will be accrued only from and treated at MSKCCand The Rockefeller University/Center for Clinical \& Translational Science . The study will assess autologous LCs presenting CT7, MAGE-A3, and WT1 after electroporation with CT7, MAGE-A3, and WT1 mRNA. Twenty patients will accrue to the study and ten will receive vaccines at 9x10\^6 LCs per dose (i.e., combination of 3x10\^6 CT7 mRNA-electroporated LCs + 3x10\^6 MAGE-A3 mRNA-electroporated LCs + 3x10\^6 WT1 mRNA-electroporated LCs) and another ten who will not receive any LC vaccines but will otherwise undergo identical cytoreduction, ASCT, and standard supportive care. At approximately 3 months after ASCT and as deemed clinically appropriate, patients will start lenalidomide maintenance therapy, which is now standard to delay disease progression. CT7, MAGE-A3, and WT1 mRNA-electroporated Langerhans cells ( LCs): Patients receive CT7/MAGE-A3/WT1 mRNA-electroporated autologous Langerhans-type dendritic cells ID on days 12, 30, and 90 after autologous stem cell transplant. Patients on the vaccine arm of the study will receive a total of 3 vaccinations, comprising a primary immunization on day +12 after ASCT followed by two boosters at days +30 and +90. Vaccines will be dosed at 9x10\^6 LCs per vaccine x 3.

Patients receive standard of care treatment after autologous stem cell transplant Standard of care: No vaccines