Safety and efficacy of autologous stem cell transplantation in dialysis-dependent myeloma patients-The DIADEM study from the chronic malignancies working party of the EBMT.

The role of high-dose chemotherapy followed by autologous stem cell transplantation (ASCT) in the treatment of myeloma (MM) patients with severe and/or dialysis-dependent renal impairment remains uncertain. We report on the outcomes of 110 patients (median age 57 years) who had become dialysis-dependent pre-ASCT and who underwent a first ASCT between 1997 and 2017. Sixty-three (57%) patients had light chain MM. All patients required dialysis (94% hemodialysis and 6% peritoneal). Forty-four of 71 (62%) patients received bortezomib-based induction regimens and 42 (39%) patients had achieved at least a very good partial response (VGPR) pre-ASCT. Melphalan dosing was as follows: ≤140 mg/m2 (82%), and >140 mg/m2 (18%). The median PFS after ASCT was 35 months (95% CI: 21.5-42.2) and the median OS 102 months (95% CI: 70.4-129.1). At 1, 2, and 5 years after ASCT, 8% (95% CI 3-14%), 13% (6-20%), and 20% (12-29%) of patients, respectively, had achieved dialysis independence. In multivariate analyses of OS and PFS including age at ASCT, response at ASCT, and year of ASCT, younger age at ASCT and better response at ASCT (CR/VGPR/PR vs. MR/SD/progression) were significantly associated with better OS and PFS.