USE OF GRANULOCYTE-MACROPHAGE COLONY-STIMULATING FACTOR IN THE TREATMENT OF PROLONGED HEMATOPOIETIC DYSFUNCTION AFTER CHEMOTHERAPY ALONE ORCHEMOTHERAPY PLUS BONE-MARROW TRANSPLANTATION

This study evaluates the use of granulocyte-macrophage colony stimulat ing factor (GM-CSF) in patients with prolonged haematopoietic dysfunct ion (>21 days) after using chemotherapy to treat cancer. One hundred a nd seven patients were identified who had a leueocyte count below 1000 cells/mm(3) more than 21 days after start of chemotherapy (81 patient s) or after bone marrow transplantation (BMT) (26 patients). There wer e 66 males and 40 females ranging in age from 4.5 to 82 years. The dur ation of aplasia was 48 +/- 43 days in the chemotherapy alone group, a nd 79 +/- 57 days in the post BMT group. Over 80% of the patients had haematologic malignancies and 70% had an infection prior to the start of the cytokine. Patients received 5 mu g GM-CSF/kg(1) body weight dai ly i.v. or s.c. for 14 +/- 11 days in the chemotherapy group and 20 +/ - 26 days in the BMT group. Sixty percent of chemotherapy patients and 58% of BMT patients had a haematological response to treatment (leuco cyte count >2000 cells/mm(3). Median times to haematologic recovery we re 7 days in the chemotherapy group and 10 days in the BMT group. Ther e was a significant reduction in the number of infections (73% to 28% in the chemotherapy group). Clinical responses in the two groups were 55% and 50%, respectively. No severe, drug-related adverse events were reported and no evidence of stimulation of malignant clones was obser ved. It is concluded that GM-CSF is effective and well tolerated in pa tients with prolonged bone marrow dysfunction after chemotherapy or BM T. Although results from an open-label trial must be viewed with cauti on, this observation confirms the value and safety of GM-CSF therapy i n patients with this severe, and often fatal condition.