Outcomes in patients with multiple myeloma and renal impairment undergoing autologous hematopoietic cell transplantation

Renal impairment (RI) is a known risk factor for patients with multiple myeloma (MM) undergoing autologous hematopoietic cell transplantation (AHCT), yet data on transplant outcomes in resource-constrained settings are limited. This retrospective study evaluated AHCT outcomes in 53 MM patients with RI (creatinine > 2 mg/dL or clearance < 40 mL/min) treated at a public hospital in Brazil between 2010 and 2023. The median age was 59 years, 82% Durie-Salmon IIIA/B, 63% International Staging System (ISS) III, and 81% of patients received melphalan ≤ 140 mg/m². Fifteen patients (28%) were dialysis-dependent at AHCT. The number of patients developing grade 3–4 overall toxicity, oral mucositis, diarrhea and nausea were 15 (29%), 9 (17%), and 7 (13%), respectively. Being in partial response vs. very good or complete response ( p =.024), low albumin at transplant ( p =.018), and a melphalan dose > 140 mg/m² ( p =.043) were associated with increased grade 3–4 overall toxicity. Fourteen (26%) patients required admission to intensive care unit. Non-relapse mortality at 100 days was 13%, mainly infection-related. The 24-month progression-free survival (PFS) and overall survival rates (OS) were 48% and 65%, respectively. Dialysis dependence at transplant ( p =.035) and having an ISS of 2 ( p =.017) or 3 ( p =.015) were associated with worse PFS, while having higher comorbidity burden ( p =.015) with worse OS. AHCT in this setting was associated with high NRM and frequent intensive care utilization, but survival was comparable to prior studies. Taken together, optimizing patient selection for HCT and reducing melphalan dose in patients with RI may be warranted in resource-limited settings.