Efficacy of the combination of bortezomib and dexamethasone in systemic AL amyloidosis

Bortezomib–dexamethasone (Btz/Dex) is an active regimen in patients with multiple myeloma and has been used in few patients with amyloidosis. Here, we report a retrospective evaluation of the efficacy and toxicity of Btz/Dex in 26 patients with AL amyloidosis (AL). Eighteen patients (69%) received Btz/Dex as first-line treatment. Organs most frequently involved were kidneys (100%) and heart (35%); five patients (19%) had less than two organs involved. The overall response rate was 54% (14 of 26 patients), with eight patients (31%) achieving a hematologic complete remission (CR). All patients who reached a CR received Btz/Dex as first-line therapy. Median time to response was 7.5 weeks. Improvement in organ function was noticed in three patients (12%). Median progression-free survival (PFS) and overall survival (OS) was 5.0 and 18.7 months, respectively; in CR patients, however, median PFS and OS have not yet been reached. Toxicities were manageable, with hematological side effects being most common. No grade 3/4 neuropathy was observed. Our results confirm the activity of bortezomib/dexamethasone in patients with AL amyloidosis and suggest that patients achieving a CR have a marked benefit for survival.