OUTLINE: This is a dose escalation, multicenter study. Patients receive dimethylxanthenone acetic acid (DMXAA) IV over 20 minutes once weekly for 6 weeks, followed by 2 weeks of rest. An additional course of therapy may be administered in the absence of unacceptable toxicity or disease progression. Cohorts of 3 patients receive escalated doses of DMXAA until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose preceding that at which 2 of 3 patients experience dose limiting toxicity.