Plerixafor and Abbreviated-Course Granulocyte Colony–Stimulating Factor for Mobilizing Hematopoietic Progenitor Cells in Light Chain Amyloidosis

• Plerixafor plus granulocyte colony–stimulating factor mobilization is safe and effective in light chain amyloidosis.
• Plerixafor plus granulocyte colony–stimulating factor mobilization leads to significantly less weight gain and granulocyte colony–stimulating factor exposure in light chain amyloidosis.

Cytokine-based mobilization in light chain (AL) amyloidosis is frequently complicated by fluid overload, weight gain, cardiac arrhythmias, and peri-mobilization mortality. We analyzed hematopoietic progenitor cells (HPC) mobilization outcomes in 49 consecutive AL amyloidosis patients at our institution between 2004 and 2013 with granulocyte colony–stimulating factor (G) (10 μg/kg/day) (n = 25) versus an institutional protocol to limit G exposure using plerixafor (P) (.24 mg/kg s.c. starting day 3 of G 10 μg/kg) (n = 24). G+P strategy yielded higher total CD34+ cells/kg (12.8 × 106 versus 6.3 × 106; P < .001) and CD34+ cells/kg collected on day 1 (10.8 × 106 versus 4.9 × 106, P = .004) compared with the G cohort. More G+P patients collected ≥5 × 106 CD34+ HPCs/kg (22 versus 16, P = .02) and ≥ 10 × 106 CD34+ HPCs/kg (13 versus 5, P = .01). Four patients (16%) had mobilization failure with G; none with G+P. Peri-mobilization weight gain was lower with G+P strategy (median weight gain 1 versus 7 pounds, P = .009). Numbers of apheresis sessions (median, 1 versus 1, P = .52), number of hospitalization days (median, 1.1 versus 1.6, P = .52), transfusions, use of intravenous antibiotics, and cardiac arrhythmias were similar. In conclusion, our study demonstrates that upfront use of G+P as a mobilization strategy results in superior HPC collection, no mobilization failures, and less weight gain than G alone.