In 1980, a consensus chemotherapy intergroup study for advanced malignant mesothelioma was initiated based on a collaborative agreement among the Eastern Cooperative Oncology Group (ECOG), the Southwest Oncology Group (SWOG), and the Southeastern Cancer Study Group (SECSG). The purpose of the study was to evaluate cyclophosphamide (500 mg/m2 day 1), imidazole carboxamide (250 mg/m2 days 1 through 5), and doxorubicin (Adriamycin; Adria Laboratories, Columbus, OH) (50 mg/m2 day 1) v cyclophosphamide (500 mg/m2) and doxorubicin (50 mg/m2) in a randomized prospective clinical trial involving 76 fully evaluable patients with advanced stages II to IV malignant mesothelioma. A total of nine responses (12%) were documented, including three complete and six partial responses. There was no significant difference in response duration or survival between treatment arms. Leukopenia (greater than 2,000/microL) was observed in 46% of patients treated with the three-drug combination and 38% of patients receiving the two-drug combination. The variables of performance status 0-1 and the absence of prior chemotherapy/radiotherapy were significant with respect to favorable impact on survival. We conclude, based on the minimal benefit observed, that the combination of cyclophosphamide and doxorubicin with or without imidazole carboxamide does not warrant further investigation in patients with advanced-stage malignant mesothelioma.