Induction Therapy with Bortezomib and Dexamethasone and Conditioning with High-Dose Melphalan and Bortezomib Followed by Autologous Stem Cell Transplantation for Immunoglobulin Light Chain Amyloidosis: Long-Term Follow-Up Analysis.

In immunoglobulin light-chain (AL) amyloidosis, the depth of hematologic response to treatment is associated with improved survival and organ responses. We conducted a clinical trial using bortezomib in induction and in conditioning with melphalan before stem cell transplantation (SCT) for AL amyloidosis. The results of this clinical trial with a median follow-up of 36 months have been reported previously. Here we report the long-term results of this clinical trial with a median follow-up of 77 months. We describe survival, durability of hematologic and organ responses, and relapse rates. Thirty-five patients were enrolled between 2010 and 2013. Hematologic complete response and very good partial response (VGPR) were noted in 100% (27 of 27) of the evaluable patients at 6 months post-SCT. Four patients (15%) had hematologic relapse at a median of 42 months, and 1 patient (3.7%) had organ progression despite maintaining a VGPR at 37 months. The median overall survival and progression-free survival have not yet been reached at the time of this report. Renal and cardiac responses occurred in 65% and 88%, respectively, at 5 years post-SCT. The median time to renal and cardiac response was 12 months and 6 months, respectively. In conclusion, incorporating bortezomib into induction and conditioning yielded durable hematologic responses of AL amyloidosis, with corresponding organ responses and prolonged survival.