Induction bortezomib in Al amyloidosis followed by high dose melphalan and autologous stem cell transplantation: a single institution retrospective study.

Introduction/background: High-dose melphalan (HDM) followed by autologous stem cell transplant (ASCT) for light chain amyloidosis (AL) was performed in 31 patients at Oregon Health and Science University between 2005 and 2012. Fifteen patients had cardiac involvement.

Patients And Methods: Patients received melphalan 200 mg/m(2) or dose-adjusted HDM (100-140 mg/m(2)) depending on high risk features. Thirteen patients proceeded directly to ASCT after diagnosis, 12 patients received a bortezomib-containing regimen, and 6 received a variety of other induction regimens.

Results: The day 100 treatment-related mortality was 9.6%. Overall hematologic (ORR) and organ response rates (OR) in the whole cohort after ASCT were 77% and 58%. ORR and OR in the bortezomib pretreated group were 92% and 75% vs. 69% and 54% in the group that received no pretreatment. The median time to maximum hematologic response after ASCT was reduced in the group that received bortezomib induction (3 vs. 14 months). Overall cardiac response rate was 60%; 100% in patients pretreated with bortezomib and 43% in those without induction treatment. With a median follow-up of 2.9 years, the 3-year progression-free and overall survival rates in the entire cohort were 66% and 73% and in those with cardiac involvement, 73% and 80%.

Conclusion: We observed that bortezomib-based induction is well tolerated in patients with and without cardiac involvement and suggest that this approach be studied in prospective multi-institutional trials.