If you choose to join this study, you will get a random assignment (like a coin flip) to 1 of 2 study regimens. GROUP A: If you are in this group, you will get the standard treatment for your diagnosis.

• You will get 4 cycles (28-day periods) of induction chemotherapy using the drugs daratumumab and bortezomib.
• 4-6 weeks after you finish induction chemotherapy, you will get treatment to stimulate the production of bone marrow stem cells and then have these cells collected.
• 1-2 weeks after your stem cells are collected, you will get a high dose of a drug called melphalan and then have your stem cells returned to your body.
• After your stem cell transplant, you will get another 2 cycles of treatment with daratumumab and bortezomib.
• After your final doses of daratumumab and bortezomib, you will get a drug called lenalidomide every 4 weeks for as long as the study doctor believes you need it.

GROUP B: If you are in this group, you will get the experimental regimen with the study drug.

• Before starting the study regimen, you will have some of your white blood cells collected through a process called apheresis. Your collected white blood cells will be shipped to a CAR-T cell lab to be genetically modified and made into the study drug.
• You will get 6 cycles (28-day periods) of induction chemotherapy using the drugs bortezomib, lenalidomide, and dexamethasone or using bortezomib, cyclophosphamide, and dexamethasone (the study doctor will choose whichever combination they believe is most appropriate).
• You will get a single dose of the study drug after you finish the induction chemotherapy.
• After your dose of the study drug, you will get lenalidomide every 4 weeks for as long as the study doctor believes you need it.

No matter to which group you are assigned, you will visit our clinic once per month for up to 2 years after you stop taking your study regimen. We will keep in touch with you for up to 15 years to see how you are doing.