Doxorubicin plus ifosfamide with rhGM-CSF in the treatment of advanced adult soft-tissue sarcomas: preliminary results of a phase II study from the EORTC Soft-Tissue and Bone Sarcoma Group

Abstract

Doxorubicin and ifosfamide are the two most active agents used in the treatment of advanced inoperable soft-tissue sarcoma, but their use in combination produces dose-limiting myelosuppression. To explore the feasibility of combining optimal doses of both drugs, doxorubicin (75 mg/m2) and ifosfamide (5 g/m2) were given every 3 weeks with recombinant human granulocyte/macrophage-colony-stimulating factor (rhGM-CSF; 250 micrograms m-2 day-1) by subcutaneous injection for up to 14 days after each course. A total of 52 patients with progressive metastatic soft-tissue sarcoma were entered, none having received prior chemotherapy. One patient was ineligible and received no treatment after registration. Preliminary analysis of six cycles of chemotherapy revealed that the full protocol dose intensity had been administered to the majority of patients. Although the median leucocyte and neutrophil counts did not fall with subsequent courses of chemotherapy, the duration of neutropenia increased with each course delivered. Cumulative thrombocytopenia was a major dose-limiting toxicity and was the main reason for any dose modifications that occurred. Although 26 patients experienced infections after one or more courses of treatment, in only 7 was admission required for parenteral antibiotics. One patient died as a result of septicaemia after the first cycle of treatment. To date, there have been 22 responses (43%) with 8% complete remissions. It appears that the administration of rhGM-CSF allows this high-dose regime of chemotherapy to be given safely and the early encouraging response rate adds support to the concept that increasing the dose of doxorubicin improves the outlook for patients with advanced soft-tissue sarcomas.