Bortezomib-Based Induction Is Associated with Superior Outcomes in Light Chain Amyloidosis Patients Treated with Autologous Hematopoietic Cell Transplantation Regardless of Plasma Cell Burden

Abstract

The benefits of pre-transplant induction chemotherapy in light chain (AL) amyloidosis, a low burden plasma cell (PC) neoplasm associated with multiorgan dysfunction, is debatable, although with the availability of bortezomib, this approach is being increasingly pursued. We analyzed the outcomes of AL amyloidosis patients undergoing autologous hematopoietic cell transplant between 2014 and 2018 that were reported to the Center for International Blood and Marrow Transplant Research database. Of 440 patients, 294 received bortezomib-based induction, and 146 received no induction. Patients receiving induction had greater PC burden compared to no induction (PC 10% or more, 39% versus 11%; P < .01). At 2 years, the induction group compared to no induction had lower relapse/progression: 13% (9% to 18%) versus 23% (16% to 32%) (P = .02); better progression-free survival (PFS): 82% (77% to 87%) versus 69% (61% to 77%) (P < .01); and similar overall survival (OS): 92% (88% to 95%) versus 89% (84% to 94%) (P = .22), findings that were confirmed on multivariate analysis. A subset analysis limited to patients with <10% PC also showed superior relapse/progression (hazard ratio [HR], .43; 95% confidence interval [CI], .24 to .78; P < .01) and PFS (HR, .43; 95% CI, .26 to .72; P < .01) for induction compared to no induction. Thus, we conclude that pre-transplant bortezomib-based induction was associated with improved relapse/progression and PFS in AL amyloidosis. Longer survival follow-up is warranted, as OS was excellent in both cohorts at 2 years.

Keywords: Bone marrow transplant; Hem malignancies; Myeloma.