Outpatient Versus Inpatient Administration of Ciltacabtagene Autoleucel in Multiple Myeloma: A Systematic Review of Clinical, Economic, and Humanistic Outcomes

<b>Background/Objectives</b>: Ciltacabtagene autoleucel (cilta-cel) for relapsed/refractory multiple myeloma is typically administered inpatient (IP) to monitor for cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). Because cilta-cel toxicities are typically delayed, outpatient (OP) administration (infusion and early monitoring) is being explored. We synthesized available evidence on OP and IP administration. <b>Methods</b>: MEDLINE, Embase, and Cochrane Library were searched from inception to 5 August 2025, supplemented by conference and gray literature searches. Eligible studies of adults with multiple myeloma receiving cilta-cel reported efficacy, safety, resource use, costs, and/or quality-of-life outcomes; findings were synthesized descriptively due to heterogeneity. <b>Results</b>: Seventy-four records (56 studies) were included; 90 patients received OP cilta-cel. OP clinical evidence (primarily three real-world studies) showed high response rates (ORR: 95%; median follow-up 4.6 months) and reported 1-year PFS and OS of 86% and 96%. In IP studies, median ORR was 91%, with median 1-year PFS 76% and median 1-year OS 85%. Any-grade CRS and ICANS occurred in 79-84% and 17-22% of OP patients (largely low grade); IP cohorts reported a median ICANS incidence of 17% (range 5-23%). Most OP patients were later hospitalized (86-93%), but stays were shorter (median 4-6.5 days) than in an IP cohort (median 19 days). Comparisons were unadjusted and may reflect selection differences. One modeling-based economic analysis estimated savings of ~$19,000 per OP-treated patient. <b>Conclusions</b>: OP cilta-cel appears feasible for selected patients and may reduce costs without compromising outcomes. Findings are descriptive and hypothesis-generating and prospective multicenter studies are needed to define long-term safety, durability, quality of life, and cost-effectiveness.