Background: It is well known that the staging stratification at diagnosis predicts survival in immunoglobulin light chain (AL) amyloidosis, but there is a paucity of literature delineating the prognostic value of these systems at the time of 2nd-line therapy.Methods: We conducted a retrospective study to evaluate the prognostic value of AL staging among 563 patients with staging data, who initiated a 2nd-line therapy between 2000 and 2015. Both the Revised Mayo 2012 staging system and the European revision of the Mayo 2004 staging system were used.Results: The median time from initial treatment to 2nd-line therapy was 11.6 months. Median follow-up from institution of 2nd-line therapy was 54.1 months. The 1st-line therapy for patients was autologous stem cell transplant (ASCT) in 216 (38%) patients; and 2) non-ASCT therapies in 347 patients. Both staging systems were prognostic with a risk ratio of 9.4 (95%CI: 6.0, 15.1; p<0.0001) between stage IIIb and I, and of 12.2(8.1, 18.5; p<0.0001) between IV and I. At the time of 2nd-line therapy the staging systems' predictive values were independent of what the patients' 1st-line therapies had been despite the fact that the median time from initial treatment to 2nd-line therapy was 19.4 months in ASCT group and 8.0 months in non-ASCT group. Among the patients receiving 2nd-line therapy after ASCT, the 5-year overall survival (OS) from 2nd-line therapy for those with ≤ stage II versus >stage II was 65% and 31% (Mayo 2004) and 70% and 23% (Mayo 2012). The respective numbers for patients relapsing from a non-ASCT therapy were 57% and 26% (Mayo 2004) and 60% and 23% (Mayo 2012).Conclusions: This study indicates that the Mayo staging systems work well at the time of instituting 2nd-line therapy and is independent of whether 1st-line therapy was ASCT based. DisclosuresGertz:annexon: Consultancy; Medscape: Consultancy; Apellis: Consultancy; celgene: Consultancy; Prothena: Honoraria; Abbvie: Consultancy; Amgen: Consultancy; Physicians Education Resource: Consultancy; spectrum: Consultancy, Honoraria; Ionis: Honoraria; Research to Practice: Consultancy; Teva: Consultancy; janssen: Consultancy; Alnylam: Honoraria. Kumar:KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding. Lacy:Celgene: Research Funding. Dingli:Millennium Takeda: Research Funding; Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Millennium Takeda: Research Funding. Kapoor:Takeda: Research Funding; Celgene: Research Funding. Russell:Vyriad: Equity Ownership. Dispenzieri:Celgene, Takeda, Prothena, Jannsen, Pfizer, Alnylam, GSK: Research Funding.