Impact of consolidation therapy post autologous stem cell transplant in patients with light chain amyloidosis

The role of consolidation post autologous stem cell transplant in light chain amyloidosis is not well defined. We retrospectively identified patients who had light chain amyloidosis and underwent autologous stem cell transplant at the Mayo Clinic. Consolidation was defined as any treatment given after the day 100 evaluation post-transplant to maintain or deepen the response. We identified 471 patients, of whom 72 (15%) received consolidation. Patients receiving consolidation had more advanced disease (Mayo 2012 stage ≥II in 67% vs 52%, P =.02), and had lower day 100 response rates (very good partial response or better: 35% vs 84%, P <.001). After consolidation, rates of very good partial response improved from 24% to 28%, and rates of complete response improved from 11% to 40%. Patients with less than very good partial response who received consolidation, had better progression-free survival (median of 22.4 vs 8.8 months, P <.001), and the benefit was greater in those who deepened their response (median of 41 vs 8.8 months, P <.001). In patients with less than very good partial response, there was a trend for better overall survival in patients who responded to consolidation (median of 125.8 vs 74.4 months, P =.07). In patients who achieved very good partial response, or better, at day 100 post autologous stem cell transplant, consolidation did not improve progression-free or overall survival. Consolidation after autologous stem cell transplant for light chain amyloidosis improves progression-free survival for patients who achieve less than very good partial response.