Introduction: Renal impairment is a common and serious complication in multiple myeloma (MM), affecting treatment decisions and prognosis. Understanding the relationship between MM and renal impairment is essential to achieve improved outcomes. The purpose of this study is to assess the effectiveness of autologous stem cell transplantation (ASCT) in patients with impaired renal function in conjunction with MM, aiming to provide data on the efficacy.
Methods: We retrospectively analyzed 21 patients with renal failure (creatinine > 2.0 mg/dL, < 40 mL/min/1.73 m²) at the diagnosis of MM who underwent ASCT between 2014 and 2024 at our center. Disease characteristics were noted, as well as the HCT-CI score for risk assessment, induction and conditioning regimens, responses based on International Myeloma Working Group criteria, and survival analysis.
Results: Twenty-one patients were enrolled in this study. Fourteen were male, and seven were female. The median age at diagnosis was 58 years (42-68). The median follow-up time was 56 months (15-111). Sixteen patients (76%) had ISS stage III. The HCT-CI score indicated that 12 patients (57%) had a high-risk score. At diagnosis, five patients were undergoing renal replacement therapy (RRT), while for non-RRT patients, the median eGFR was 24.6 mL/min/1.73 m² (8.7-35.7). The median time from diagnosis to ASCT was 10 months (2-24). Thirteen patients (62%) proceeded to ASCT after a single line of therapy. During the transplant, a low-dose melphalan regimen was used in 9 patients (43%) considering their renal impairment status. For non-RRT patients, the median eGFR at transplantation was 57.3 mL/min/1.73 m² (15.5-113.6), with four patients on RRT. Induction treatment responses were: PR in 8 patients (38%), VGPR in 9 patients (42%), and CR in 4 patients (19%). ASCT was performed with a median stem cell count of 4.1x10⁶ cells/kg (2.2x10⁶-6.3x10⁶). No patients experienced graft failure. The median duration of neutrophil and platelet engraftment was 10 days (9-13) and 11 days (6-16), respectively. At day +100 post-ASCT, 11 patients (52%) achieved CR, 7 patients (33%) achieved VGPR, and 2 patients (9%) achieved PR, while 1 patient experienced disease progression. Thirteen patients received lenalidomide as maintenance therapy, and eight were followed without maintenance treatment. The median progression-free survival was 46 months (13-86), and the overall survival was 56 months (12-116).
Conclusions: ASCT can be a safe and effective treatment option for MM patients with renal impairment, including those on RRT, as long as careful patient selection and monitoring are performed. Approaches like melphalan dose reduction allow for tailored treatment strategies that address the unique challenges faced by these patients, ensuring optimal outcomes and minimizing potential complications. By demonstrating the feasibility of ASCT in this group, our study underscores the importance of individualized care and follow-up to achieve successful transplantation results.
