Phase I study of adozelesin (U-73,975) in patients with solid tumors.

During a phase I clinical and pharmacologic trial, 26 patients with refractory solid tumors were treated with increasing doses of adozelesin by brief intravenous infusion every 3 weeks. Overall, adozelesin was well tolerated. The dose-limiting toxicity was myelosuppression, mainly thrombocytopenia and leukopenia. Nonhematologic toxicity was generally mild, with fatigue (36%), local reaction at the infusion site (24%), nausea or vomiting (20%) and hypersensitivity reaction (16%) being the most common adverse effects. There were no objective clinical responses. The maximally tolerated dose on this schedule was 188 micrograms/m2 with the recommended phase II starting dose being 150 micrograms/m2 on an every 3 week schedule. Adozelesin merits broad investigation at the phase II level.