Outcomes and treatments of patients with immunoglobulin light chain amyloidosis who progress or relapse postautologous stem cell transplant

Immunoglobulin light chain (AL) Amyloidosis is a condition whereby misfolded proteins generated by plasma cells deposit in tissues causing organ dysfunction. Chemotherapy and autologous stem cell transplant when eligible are standard treatment options. Several studies report long-term outcomes of patients post-transplant. However, there is a paucity of literature describing outcomes of relapsed patients post-transplant. We performed a retrospective study to assess outcomes and therapies employed upon relapse after transplant. Between 1996 and 2009, 410 patients received transplant at the Mayo Clinic as first-line therapy. Of those patients, 42 (10%) died within 3 months of transplant, 64 (16%) died without documented relapse, 158 (38%) were alive without documented progression, and 146 (36%) had documented progression. Those 146 patients are the subject of our study, and their median time to hematologic relapse/progression was 23.6 months (95%CI 18.3, 26.3 months). Their median overall survival and 5-yrs overall survival from post-transplant relapse/progression was 51.7 months (95%CI 34.1-62.3) and 39%, respectively. The most common first regimen for treatment after relapse was lenalidomide or thalidomide. In conclusion, our study indicates that patients with AL amyloidosis fare well post-transplant relapse/progression. Additionally, it provides a yardstick to design clinical trials to determine best treatment options.