Phase I clinical trial of spirogermanium

Spirogermanium is a new azaspirane antitumor agent, with the metal germanium substituted for a one-carbon moiety in the ring structure. This drug inhibits DNA and RNA synthesis in HeLa cells, is cytotoxic in vitro, and has curative in vivo antitumor activity against the ascitic Walker 256 carcinosarcoma in rats. No hematologic toxicity was recorded during the preclinical toxicologic evaluation. The principal clinical toxic effects observed in this phase I trial were neurologic, manifested as lethargy, dizziness, and ataxia, while a grand mal seizure was produced after an accidental overdose. There was no evidence of hematologic, renal, or hepatic toxicity. A partial response was achieved in a patient with a well-differentiated lymphocytic lymphoma. We recommend that phase II trials be conducted with a twice or thrice weekly dose of 50-80 mg/m2, administered in a 30-minute iv infusion.