Lymphodepleting Total Body Irradiation (TBI) Plus Cyclophosphamide Prior to Ciltacabtagene Autoleucel (Carvykti; Cilta-cel) for Multiple Myeloma (MM) Patients With Impaired Renal Function

Treatment for relapsed/refractory multiple myeloma continues to evolve with the approval of highly effective anti-BCMA CAR T therapies in recent years. However, despite the high prevalence of renal insufficiency in this population, pivotal clinical trials have excluded patients with impaired renal function, leading to an urgent, unmet clinical need to develop safe and effective lymphodepleting regimens prior to CAR T administration for this population. In addition, renal insufficiency is linked to poor disease-related outcomes and is highly associated with several underserved populations. This study is testing the hypotheses that: 1. low-dose total body irradiation (TBI) in combination with cyclophosphamide (Cy) as lymphodepletion prior to administration of cilta-cel will be safe and tolerable in patients with multiple myeloma who have impaired renal function 2. low-dose TBI-Cy as lymphodepletion prior to cilta-cel will result in comparable CAR T expansion/persistence and disease response rates as those seen with standard lymphodepleting chemotherapy (fludarabine / cyclophosphamide).