Stem cell transplantation compared with melphalan plus dexamethasone in the treatment of immunoglobulin light‐chain amyloidosis

BACKGROUND Autologous stem cell transplantation (SCT) is a common management strategy for select patients with immunoglobulin light‐chain amyloidosis, but no trials have documented improved overall survival. METHODS Eighty‐nine patients with biopsy‐proven immunoglobulin light‐chain amyloidosis were allowed to select treatment with melphalan plus dexamethasone (n = 34) or SCT (n = 55); all patients were transplant eligible. Treatment preference resulted in imbalanced study arms. Patients who selected SCT were younger, more frequently had an Eastern Cooperative Oncology Group performance status score less than 2, had lower‐stage amyloidosis, and had a lower incidence of cardiac amyloidosis. RESULTS Patients receiving melphalan plus dexamethasone had a 3‐year progression‐free survival rate of 29.1% and an overall survival rate of 58.8%. Patients undergoing SCT had a 3‐year progression‐free survival rate of 51.7% and an overall survival rate of 83.6%. An attempt to match patients between the 2 arms in terms of risk produced 24 matched triplet sets (2 SCT patients for each melphalan‐dexamethasone patient); there was no difference in hematologic response, but there was better survival after autologous SCT. A propensity score–matched analysis of the cohorts (melphalan plus dexamethasone vs SCT) showed an overall mortality hazard ratio of 2.56 (P < .01). CONCLUSIONS Although the study had limitations, similar hematologic responses and improved survival were observed after SCT versus melphalan plus dexamethasone. Cancer 2016;122:2197–205. © 2016 American Cancer Society. Eighty‐nine patients with biopsy‐proven light‐chain amyloidosis were allowed to select treatment with melphalan plus dexamethasone (n = 34) or stem cell transplantation (n = 55). Twenty‐four matched triplet sets (2 stem cell transplant patients for each melphalan‐dexamethasone patient) showed no difference in hematologic response, but survival was better after autologous stem cell transplantation.