Low-dose non-glycosylated rhGM-CSF is effective for the treatment of delayed hematopoietic recovery after autologous marrow or peripheral blood stem cell transplantation.

Twenty-six patients with hematologic malignancies (20) or solid tumors (six) were treated with non-glycosylated rhGM-CSF (E. coli) for delayed hematopoietic recovery (granulocytes < 0.1 x 10(9)/l on day 21 or < 0.5 x 10(9)/l on day 28) after autologous marrow or peripheral blood stem cell transplantation. Median pretreatment granulocytes were 0.1 x 10(9)/l (range 0-0.4 x 10(9)/l). Treatment with rhGM-CSF was initiated at 60-250 micrograms/m2 subcutaneously daily with dose escalation every 7 days if there was no response. Within 14 days, 21 (84%) of the 25 evaluable patients achieved granulocytes > 0.5 x 10(9)/l and 17 (68%) had granulocytes > 1.0 x 10(9)/l. For those who responded within 14 days, granulocytes were > 0.5 x 10(9)/l at a median of 3 days (range 1-13) and > 1.0 x 10(9)/l at 6 days (range 2-12). Sixteen of the 23 patients receiving an initial rhGM-CSF dose of 60-125 micrograms/m2 achieved granulocytes > 1.0 x 10(9)/l. Three patients discontinued use of rhGM-CSF because of toxicity, and four patients never recovered despite use of rhGM-CSF doses as high as 1000 micrograms/m2. Graft failure-related mortality was 16% at 4 months after transplantation. These results demonstrate that relatively low doses of non-glycosylated rhGM-CSF administered subcutaneously daily can be used to promote granulocyte recovery in patients with delayed engraftment after autologous transplantation. No beneficial effects were seen on red cell or platelet recovery.