Dialysis dependence is associated with poor prognosis in multiple myeloma: a multicenter retrospective cohort study.

Background: Patients with multiple myeloma (MM) and renal impairment (RI), particularly those requiring dialysis, have historically experienced poor outcomes. Despite advancements in targeted therapies, the prognosis of dialysis-dependent MM and factors influencing dialysis independence remain unclear.

Objectives: This study aimed to provide a comprehensive analysis of the clinical manifestations and treatment outcomes of dialysis-dependent MM patients in China, and to explore the factors associated with dialysis independence and long-term survival.

Design: We conducted a multicenter, retrospective, real-world cohort study.

Methods: This multicenter, retrospective study included 122 MM patients requiring chronic hemodialysis (⩾28 days of treatment) at 4 comprehensive hospitals in China from January 2012 to November 2023. Hemodialysis resulting from causes other than MM was excluded. Logistic regression was employed for multivariate analysis of factors associated with dialysis independence, and Kaplan-Meier survival curves and Cox proportional hazard models were utilized for survival analysis.

Results: Among the 122 patients, 74 patients (60.7%) were male, with a median age of 65 (39-87) years. Of these, 71.3% ( = 87) had newly diagnosed MM (NDMM), and 28.7% ( = 35) had relapsed/refractory MM (RRMM). Dialysis independence was achieved in 27 patients (22 with NDMM and 5 with RRMM). Proteasome inhibitors were used in 80.3% of patients ( = 98), while 13.9% ( = 17) received daratumumab-based regimens. After a median follow-up of 43.7 months, the median progression-free survival (PFS) was 14.4 months (95% confidence interval (CI): 3.6-25.2), and the median overall survival (OS) was 27.4 months (95% CI: 6.9-47.9). Dialysis-independent patients had significantly longer PFS (36.7 vs 9.4 months,  = 0.006) and OS (62.6 vs 17.7 months,  < 0.001). Factors associated with dialysis independence included achieving a very good partial response (VGPR), receiving daratumumab-based regimens, reduction in serum-free light chain ⩾80% after the first chemotherapy cycle, and age <65 years.

Conclusion: In the era of new drugs, dialysis-dependent MM still has a poor prognosis, although dialysis independence improves survival.