Doxorubicin is the most widely studied agent for the treatment of malignant mesothelioma. In conventional doses, the response rate is approximately 17%. Higher dose doxorubicin has been successfully employed in other tumor types. Dexrazoxane has been demonstrated to reduce the cardiac toxicity associated with long term, chronic use of doxorubicin. Based upon phase I data generated by the Cancer and Leukemia Group B (CALGB) indicating that doxorubicin at a dose of 120 mg/m(2) when combined with dexrazoxane and GM-CSF could be safely administered, the CALGB undertook a phase II study of high-dose doxorubicin in patients with malignant mesothelioma. Toxicity was excessive, necessitating protocol modification and ultimately protocol termination. There were no objective responses observed. We conclude that high-dose doxorubicin administered with dexrazoxane is unacceptably toxic in this patient population.