Granulocyte-Macrophage Colony-Stimulating Factor and Interferon-Alpha 2B in Patients with Advanced Renal Cell Carcinoma

Abstract

Objective: Biological response modifiers such as interferon-α2B (IFN-α2B) have well-known clinical activities against renal cell carcinoma (RCC). Recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF) has antitumorigenic effects both in vitro and in vivo. Therefore, a phase-I/II trial of IFN-α2B and GM-CSF was performed in patients with metastatic RCC. Methods: 21 patients in groups of 3 patients received GM-CSF at 7 different dose levels (15–300 μg) subcutaneously in combination with IFN-α2B at a fixed dose of 10 × 10⁶ IU s.c. three times weekly for 12 weeks. Results: Two complete remissions have been observed, both with lung metastases only. With increasing dose levels of GM-CSF a slight tendency to more toxicity was detectable. Due to grade-3 toxicities 5 patients (24%) dropped out of the treatment schedule. Increases in WBC, neutrophils, lymphocytes, and monocytes were noted but were not related to the dose levels of GM-CSF. Conclusions: Results demonstrate that simultaneous administration of GM-CSF and IFN-α2B is tolerated up to doses of 120–150 μg GM-CSF three times weekly. But there is no additional antitumorigenic effect of GM-CSF because the overall response rate of the combined administration of GM-CSF/IFN-α2B is similar to IFN-α2B alone and there is no obvious dose relationship between increasing doses of GM-CSF and the responses.