OUTLINE: This is a dose-escalation study. Patients receive EMD 121974 IV over 1 hour twice weekly for 4 weeks. Treatment continues for an additional course in the absence of unacceptable toxicity. Patients with stable or responding disease may continue therapy indefinitely past the 2 courses until disease progression. Cohorts of 3-6 patients receive escalating doses of EMD 121974 until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose preceding that at which 2 of 3 or 2 of 6 patients experience dose limiting toxicities. Patients are followed every 3 months for the first year, and then every 4 months thereafter until disease progression.