Intervention treatment of established neutropenia with human recombinant granulocyte-macrophage colony-stimulating factor (rhGM-CSF) in patients undergoing cancer chemotherapy.

Recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) was given to 60 patients, in a double-blind, non-prophylactic study of already established chemotherapy-induced leucopenia, for 5 days by continuous intravenous infusion and twice or once daily by subcutaneous injection. Four patients were randomized to rhGM-CSF (3) or placebo (1) at each dose (1.3, 1.7, 5.5, 11, or 22 micrograms of protein/kg). Leucocyte recovery was significantly enhanced compared with controls, in a dose-dependent manner except for 22 micrograms/kg which was ineffective with a worse experience of side effects in some patients. Most adverse events occurred in equal proportions in the treated and placebo cases. Fourteen patients developed infection and were treated with antibiotics in addition to rhGM-CSF. They were joined by a further 18 febrile patients and treated with rhGM-CSF in a subsequent open-label trial. The survival from infection was related to white blood cell (WBC) count: 19 of 32 responded with increased numbers of leucocytes (WBC count above 1.5 x 10(9)/1) after 5 days of GM-CSF. Sixteen of the 19 leucocyte 'responders' recovered from infection, two died from the underlying disease and one from persistent infection. Six of the 13 patients who did not have a leucocyte response died with persistent infection. These data indicate that rhGM-CSF enhances the leucocyte count following chemotherapy and in this way saves critically ill neutropenic patients from fatal infections.