Evaluation of Outpatient Administration of Ciltacabtagene Autoleucel in Relapsed/Refractory Multiple Myeloma: Single Center Experience

Background B cell maturation antigen (BCMA)-targeted chimeric antigen receptor (CAR) T-cell therapy including ciltacabtagene autoleucel (cilta-cel: CarvyktiTM) has revolutionized the landscape of multiple myeloma (MM) treatment. Various practice styles exist for CAR T delivery in part due to difference in healthcare infrastructure and payer models. We established a dedicated cellular therapy service, Immune Cell Therapy (ICE T), at our center where CAR T patients receive specialized and focused care throughout their treatment. We evaluated the single center experience of our outpatient cilta-cel delivery model. Patient and Methods We conducted a single center retrospective study evaluating the hospitalization of relapsed/refractory MM patients treated with commercial cilta-cel at Moffitt Cancer Center (MCC) between 05/2022 and 05/2023 with a focus on first 30 days post infusion. Initial group of patients received lymphodepleting (LD) chemotherapy as outpatient (OP), followed by infusion of CAR T cells as inpatient (IP) and monitoring, then was discharged to OP ICE T service. We then modified our practice to delivery of LD chemo, cilta-cel and monitoring as entirely OP, and then only admit to IP when clinical needs arise. Patients were followed closely through day +30 post infusion and assessed for cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). Results A total of 43 relapsed/refractory MM patients were treated for above period (Table). There were 10 patients (23.3%) for scheduled IP, 6 patients (14.0%) for IP, and 27 patients (62.8%) as OP. For those with entirely IP (median duration: 19 days), 4 were hospitalized due to MM related conditions, 1 for chemo related GI toxicity, and 1 for patient preference. Of the 10 scheduled IP group (median duration: 11 days), they were all admitted on day -1 as planned. For OP group, 25 patients (92.6%) were admitted post CAR T with a median hospitalization duration of 4 (range, 1-33) days. Of those admitted, 22 (81.5%) had primary reason as CRS, and 5 others had various clinical indications (arrhythmia, infection and social reason). Amongst those who underwent OP ICE T, 3 (11.1%) required second admission within 30 days of CAR T (2 for ICANS, and 1 for infection). Overall survival (OS) and progression-free survival (PFS) were similar across the administration types, 1-year OS 96.3% (95%CI: 76.5-99.5%, p=0.068) for OP, and 1-year PFS 85.8% (95%CI: 60.6-95.5%, p=0.10) for OP with a median follow up of 7.7 months (range, 2.9 – 14.4 months) for surviving patients. Conclusions Our current OP delivery model for cilta-cel appears to be safe and feasible with close monitoring of patients undergoing CAR T cell therapy. The duration of hospitalization can be shortened with primarily OP model to better utilize healthcare resources as long as adequate patient monitoring/management structure exists.