OBJECTIVES: With increasing incidence and high rates of relapsed and refractory disease, the RRMM-related economic burden is rising. This study describes the HRU and cost-related economic burden of US-based patients with RRMM.

METHODS: MEDLINE, Embase, EconLit, and NHS-EED were systematically searched from January 2012-June 2023 to identify observational studies and trials (hospitalization-related outcomes only) describing the economic burden of RRMM. Relevant conference proceedings were also reviewed. Costs were adjusted to 2023 USD.

RESULTS: Searches identified 4,404 citations with 50 eligible records (39 unique studies) describing US-based HCRU outcomes. Resource utilization was high throughout RRMM settings and tended to increase by line of therapy (LOT); with high percentages of patients reporting at least one instance of a general practitioner visit, outpatient hospital care, emergency department visit, or an inpatient hospitalization. Four studies reported per-patient-per-month (PPPM) hospital length of stay in the 4L+ setting with estimates ranging from 1.4-1.8 days/month, thus highlighting hospitalization as a significant ongoing resource need.

Based on within-study comparisons, costs tended to increase by LOT. Total all-cause costs of care for patients since their first LOT post-triple-class exposure were estimated in a single study at $826,882 (20.9 months follow-up; n=85; 91% MM-related). Nine studies described total costs of care for triple-class exposed patients, with PPPM costs ranging from $28,748 (n=493) to $42,947 (n=154). Among the 24 studies reporting total costs of care by spending category, anti-myeloma medications (19-65% of total costs, n=24 studies) and outpatient hospital care (13-68% of total costs, n=14 studies) emerged as primary cost drivers.

CONCLUSIONS: Our review highlighted the substantial economic burden of RRMM in the US. HCRU tended to increase with LOT, with medication costs and all types of hospital visits being important drivers. To reduce this burden, effective treatments that mitigate prolonged resource utilization, and associated costs, are needed particularly in the more costly later-line settings.