Higher Stem Cell Dose Infusion after Intensive Chemotherapy Does Not Improve Symptom Burden in Older Patients with Multiple Myeloma and Amyloidosis

Autologous hematopoietic stem cell transplantation (ASCT) for multiple myeloma (MM) is associated with high symptom burden, particularly for older patients and those with amyloid light-chain (AL) amyloidosis. Symptom burden peaks during leukopenia. We hypothesized that higher doses of CD34+ stem cells would be associated with an improved symptom outcome. Patients undergoing ASCT for MM who were ≥60 years old or had AL amyloidosis were randomized to receive either a standard (4 to 6 × 106 cells/kg) or high dose (10 to 15 × 106 cells/kg) of CD34+ cells after melphalan 200 mg/m2. Symptom burden was assessed via the MD Anderson Symptom Inventory MM module. Eighty patients were enrolled. Median CD34+ cell doses were 5.1 × 106 cells/kg (standard dose) and 10.5 × 106 cells/kg (high dose). The most severe symptoms during the first week were fatigue, lack of appetite, drowsiness, disturbed sleep, and pain. The area under the curve for the mean composite severity score of these symptoms was similar between treatment arms (P = .819). Median times to neutrophil, lymphocyte, and platelet engraftment were also similar between groups. IL-6 increased similarly for both groups throughout the ASCT course. Infusion of higher autologous stem cell dose after high-dose chemotherapy does not yield a difference in symptom burden or engraftment time in the first few weeks after ASCT.