Induction Therapy with Bortezomib Followed by Bortezomib-High Dose Melphalan and Stem Cell Transplantation for Light Chain Amyloidosis: Results of a Prospective Clinical Trial

The depth of hematologic response has been shown to correlate with survival and organ responses for patients with light chain (AL) amyloidosis. We conducted a prospective trial of 2 cycles of induction with bortezomib and dexamethasone on a twice a week schedule followed by conditioning with bortezomib and high-dose melphalan (HDM) and autologous stem cell transplantation (SCT). The objectives were hematologic responses, tolerability, and survival. Thirty-five patients were enrolled from 2010 to 2013. Of these, 30 proceeded with SCT, whereas 5 did not because of clinical deterioration during induction (n = 3) or complications after stem cell collection (n = 2). Two patients developed features of an autologous graft-versus-host disease-like syndrome post-SCT, which responded to steroids; no other unusual complications were seen. Treatment-related mortality occurred in 8.5% (3/35). Hematologic responses were achieved by 100% of the 27 assessable patients (63% complete response, 37% very good partial response [VGPR]) who completed the planned treatment. By intention-to-treat, hematologic responses occurred in 77% of patients (49% complete response, 29% VGPR). With a median follow-up of 36 months, the median overall survival and progression-free survival were not reached. In conclusion, incorporating bortezomib into induction and conditioning yielded a high rate of hematologic responses after HDM/SCT in patients with AL amyloidosis.