A Phase I trial of spirogermanium administered on a continuous infusion schedule

We have evaluated the toxicity of the antitumor agent spirogermanium on a schedule of continuous intravenous administration for periods up to five days. The doses tested were between 100 mg/m2/day and 500 mg/m2/day. Peripheral vein phlebitis occurred at all dose levels and was not relieved by addition of hydrocortisone or heparin to the infusion. No phlebitis occurred when the drug was administered through a central vein. The dose limiting toxicity of spirogermanium was neurologic, notably tremors and mental confusion. These problems became progressively more severe at doses above 250 mg/m2/day. There was no discernible bone marrow, renal or hepatic toxicity. One patient developed reversible interstitial pneumonitis. The recommended Phase II dose of spirogermanium is 200 mg/m2/day for five days, with the possibility of escalation in selected patients. Because spirogermanium is more toxic to tumor cells with prolonged exposure than with intermittent exposure, this schedule could be considered for Phase II trials, particularly in diseases thought to be especially sensitive such as ovarian and prostatic carcinoma or lymphomas.