LAUSR

IgM related AL amyloidosis is a rare disease with patients presenting with more renal and neurological involvement and less cardiac involvement compared to those with non-IgM related disease. We retrospectively reviewed 38 patients receiving autologous stem cell transplant (ASCT) for IgM related AL amyloidosis at the Mayo Clinic between May 1999 and June 2018. Median age was 61 years and 71% were male. The most common organs involved were renal (63%), neurological (32%) and cardiac (26%). The median difference between involved and uninvolved free light chains (dFLC) was 6.2 mg/dL and most patients had early mayo stage (87% Mayo Stage I 2004 and 74% Mayo Stage I 2012). The overall response rate (ORR) was 92% with 76% of patients achieving at least a very good partial response (VGPR). Renal response was seen in 65% (15/23) of patients (median time 18 months post ASCT, range 3-52 months) and cardiac response was seen in 60% (6/10) of patients (median time 12 months post ASCT, range 10-35 months). Median progression free and overall survival was 48 and 106 months respectively, Figure 1. Organ response predicted better PFS and OS (median PFS 93 months for organ response vs 16 months for no organ response, p=0.0006 and median OS 123 months for organ response vs 41 months for no organ response, p=0.02), Figure 2. Two patients died within 100 days of transplant representing a 5% 100 day mortality. ASCT is an effective therapy that can be safely delivered to carefully selected patients with IgM related AL amyloidosis.