Therapy Response Predicts Stem Cell Transplant Survival in AL Amyloidosis

In light-chain (AL) amyloidosis, a rare plasma cell disease marked by excess deposit of protein in the organs, the goal of therapy is to inhibit the production of amyloidogenic light chains and allow for organ recovery.

For patients with AL amyloidosis, depth of hematologic response to induction therapy prior to autologous hematopoietic cell transplantation (AHCT) was shown to be a predictor of post-transplant outcomes.

This new data comes from researchers from the Mayo Clinic, who conducted a retrospective study of 128 patients with newly diagnosed AL amyloidosis who received induction therapy prior to AHCT between 2007 and 2017. Median follow-up was 52 months.

Overall response rate to induction therapy was 86%, with 18% of patients achieving a complete response, 31% achieving a very-good partial response (VGPR), and 38% achieving a partial response (PR). At follow-up, the overall median progression-free survival (PFS) was 48.5 months, and median overall survival (OS) was not yet reached.

Response depth to induction therapy was associated with improved PFS and OS following AHCT. At the time of analysis, the median PFS for patients achieving at least a VGPR prior to AHCT was not reached compared with 34.1 months for patients who achieved a PR or less (P=0.0009). Median OS was also not reached for patients achieving a VGPR compared with 128 months for those achieving a PR or less (P=0.02). Upon multivariable analysis, independent predictors of OS included conditioning dose (response rate [RR], 0.42; P=0.036) and depth of response prior to transplant (RR, 0.37; P=0.0295).

This study was published in Bone Marrow Transplantation.