Elranatamab in relapsed/refractory multiple myeloma patients on hemodialysis: A real-world case series

Background Renal impairment is a frequent and adverse prognostic factor in multiple myeloma (MM), with dialysis-dependent patients largely excluded from pivotal trials of B-cell maturation antigen (BCMA)-directed therapies. Elranatamab, a BCMA×CD3 bispecific antibody, has demonstrated significant efficacy in relapsed/refractory multiple myeloma (RRMM); however, data in end-stage renal disease are extremely limited. We report real-world outcomes of four dialysis-dependent RRMM patients treated with elranatamab. Results Patients with a median age of 67 years (range 61–80) had received a median of six prior lines of therapy (range 4–7). All were refractory to proteasome inhibitors, immunomodulatory drugs, and anti-CD38 therapy, and none had prior BCMA-directed treatment. Baseline glomerular filtration rate ranged from 5 to 20 mL/min, and all patients were dialysis-dependent. At data cutoff, all four patients were evaluable for response. Two patients achieved complete response (CR), one achieved very good partial response, and one achieved partial response, resulting in an overall response rate of 100%. Treatment was ongoing in all four patients. Cytokine release syndrome (CRS) occurred in one patient (grade 1) and was self-limited. No immune effector cell-associated neurotoxicity syndrome (ICANS) events were observed. One patient developed severe pneumonia requiring intensive care unit admission; treatment was temporarily interrupted and successfully resumed without step-up dosing, maintaining CR. Hematologic toxicity was limited, with grade-4 lymphopenia in one patient. No dialysis-related complications or unexpected toxicities were observed. All patients received infection prophylaxis after hemodialysis, including trimethoprim–sulfamethoxazole, valacyclovir, and levofloxacin, with intravenous immunoglobulin administered. Conclusion In this real-world case series of dialysis-dependent RRMM patients, elranatamab demonstrated high response rates, low incidence of CRS, absence of neurotoxicity, and manageable infectious complications. These findings support the feasibility and clinical activity of elranatamab in patients undergoing hemodialysis. Larger prospective studies are warranted to confirm these encouraging results.