Effect of recombinant human granulocyte‐macrophage colony stimulating factor on progenitor cells in patients with advanced malignancies

Abstract

Haemopoietic progenitor cell levels were determined in the blood and marrow of 37 patients with advanced malignancies undergoing a phase I/II clinical trial of 0.3–30 μg/kg/d recombinant human granulocyte‐macrophage colony stimulating factor (rGM‐CSF). After injection of rGM‐CSF, the absolute number of circulating progenitor cells fell initially but after 4 d of infusion a dose‐dependent increase was observed in progenitor cells of all lineages with a slight bias favouring granulocyte‐macrophage progenitors. A mean 8.4‐fold increase in GM‐CFC and a 3.3‐fold increase in BFU‐E were observed at a dose level of 20 μg/kg/d of rGM‐CSF. Patients with malignant lymphoma showed a greater response than other patients at the same dose level and the CFU‐E rise correlated with the haematocrit. This study suggests that GM‐CSF may be of value in elevating circulating progenitor cells for subsequent autografting.