Abstract
Abstract only
8516
Background: The role of induction therapy prior to autologous stem cell transplant (ASCT) in immunoglobulin light chain (AL) amyloidosis remains controversial. Data on the prognostic impact of response to induction in a transplanted cohort are lacking. The aim of this study was to assess the impact of response to induction therapy on survival in patients undergoing ASCT for AL amyloidosis. Methods: We conducted a retrospective study of all newly diagnosed AL amyloidosis patients who received induction prior to ASCT between January 2007 and August 2017 at Mayo Clinic, Rochester, Minnesota. Patients receiving only corticosteroids prior to transplant were excluded as were those with an involved light chain of less than 5 mg/dL (not measurable for response). Results: 134 patients met inclusion criteria. The median age at diagnosis was 60 (range 36-74) and 85 (63%) were men. The most commonly used induction regimen was proteasome inhibitor-based (73.1%, n=98). The overall response rate to induction was 83% (complete response 17%, very good partial response 30% and partial response 36%). With a median follow up of 56.5 months, the median PFS and OS was 48.5 months and not reached, respectively. Response depth to induction therapy was associated with improved PFS and OS and was independent of the bone marrow plasma cell percentage. The median PFS was not reached for patients achieving ≥VGPR prior to ASCT and 33.8 months for patient achieving PR or less (P=0.001). The median OS was longer in patients with deeper responses (not reached for patients achieving ≥VGPR vs. 128 months for patients achieving PR or less (P=0.02). On multivariable analysis, independent predictors of OS were melphalan conditioning dose (RR= 0.38; P=0.018) and depth of response prior to transplant (RR 2.52; P=0.039). Conclusions: Hematologic response prior to transplant predicts post-transplant outcomes in patients with AL amyloidosis. [Table: see text]