CAR T cell treatments are now entering clinical trials. Celgene has collaborated with Bluebird bio to develop a BCMA-targeting CAR T Cell product that is now entering clinical trials. In Part A of the study (the Dose Escalation portion), patients will sign a consent form and then have a blood draw (leukapheresis) to collect their own T cells. These personal T cell swill then be manufactured with the Bluebird/Celgene product (bb21217) which engineers the cells to target the BCMA protein commonly found on the surface of myeloma cells. After the drug has been manufactured for the patient, participants will receive lymphodepletion before the bb21217 T cells are reinfused. Researchers have shown in prior studies that lymphodepletion before giving immunotherapies can enhance anti-tumor responses by expanding innate immunity, by increasing access to homeostatic cytokines, and by depressing the numbers of regulatory T cells and myeloid-derived suppressor cells. Part B of the study will be an expansion group. All patients will then be followed for up to 24 months. All subjects who complete the study, as well as those who withdraw from the study after receiving bb21217 for reasons other than death or meeting the early termination criteria, will be asked to continue to undergo long-term follow-up in a companion study. This trial is open and accepting patients at Sarah Cannon at TriStar Centennial Medical Center, Nashville TN. Learn more and connect with this trial directly at https://www.myelomacrowd.org/sparkcures-multiple-myeloma-clinical-trial-finder/?trial=906 Find eligible clinical trials for your myeloma https://www.myelomacrowd.org/sparkcures-multiple-myeloma-clinical-trial-finder/?page=search