OUTLINE: This is an open label, multicenter, dose escalation study. Patients receive GPX-100 IV once every 3 weeks. Patients receive 2 courses of treatment in the absence of disease progression or dose limiting toxicity. Treatment may continue for up to 6 courses (4 courses with prior doxorubicin) in patients with responding or non-progressing disease. One patient is entered at each of the first 3 dose levels. Cohorts of 3-6 patients are entered at subsequent dose levels. The maximum tolerated dose of GPX-100 is defined as the dose at which no more than 2 instances of dose limiting toxicity are observed in 6 patients.