A phase II trial of concomitant interferon-α-2b and granulocyte- macrophage colony-stimulating factor in patients with advanced renal cell carcinoma

This study was undertaken to test the hypothesis that the combination of granulocyte-macrophage colony-stimulating factor (GM-CSF) and interferon-α- 2b (INF-α) would have a favorable clinical impact on patients with advanced renal cell carcinoma. Fifteen patients were treated with INF-α, 5 million U/m² three times a week and GM-CSF 5 μg/kg, subcutaneously, daily. Patients received two consecutive 4-week cycles and then restaged. There were no complete responses, two of 15 partial responses (13%), and 13 of 15 had no response (87%). Biological effects (eosinophilia and leukocytosis) were characteristically observed. The therapy was well tolerated, and most side effects were attributable to INF-α. The study failed to show that the addition of GM-CSF to INF-α would increase the response rate in patients with metastatic renal cell carcinoma by enhancement of macrophage tumoricidal activity.