160 Circulating tumor DNA for measurable residual disease (MRD) detection in multiple myeloma patients undergoing CAR T-cell therapy by Tian Zhang, Hitomi Hosoya, Mia Carleton, Kailee Tanaka, Brian Sworder, Vanna Hovanky, George Duran, Michael Khodadoust, David Miklos, Sally Arai, David Iberri, Michaela Liedtke, Surbhi Sidana, David Kurtz