This trial was designed to test the ability of recombinant granulocyte macrophage-colony stimulating factor (rGM-CSF) to protect patients with refractory ovarian carcinoma from the bone marrow suppressive effects of high-dose carboplatin. A previous study with high-dose carboplatin demonstrated a response rate of 27% in patients with advanced ovarian carcinoma. Therapy was associated with severe and prolonged myelosuppression. In this trial, carboplatin was administered every 35 days at a dose of 800 mg/m sq. rGM-CSF was given at various doses beginning three days after administration of carboplatin. This study was conducted jointly with the Medicine Branch of the National Cancer Institute. Eight patients have been treated at the Biological Response Modifiers Program (BRMP). All patients experienced significant myelosuppression following high-dose carboplatin and all but one patient required dose reductions in chemotherapy due to this myelosuppression. All of the patients experienced significant thrombocytopenia and required platelet transfusions. All of the patients required hospitalization during the course of therapy. Two of the eight patients treated at the highest dose level of GM-CSF did not require hospitalization for granulocytopenia and fever. Whether GM-CSF shortens the duration of granulocytopenia cannot be determined from this study. Thrombocytopenia has remained severe and prolonged and appears not to have been affected by GM-CSF. In seven evaluable patients treated at the BRMP, there were three partial and one complete responses.