Background: This phase I study was conducted to determine maximal tolerated dose (MTD) and dose-limiting toxicities (DLT) in patients with advanced solid tumors treated with the polyamine analog N1, N14-diethylhomospermine (DEHSPM).
Methods: Patients were treated with DEHSPM administered as a subcutaneous (SC) injection daily for five consecutive days repeated every 4 weeks. Three dose levels were examined starting at 12.5 mg/m2/day, escalating to 37.5 mg/m2/day.
Results: A total of 15 patients were enrolled. Dose limiting toxicities (grade 3 or 4) included nausea, vomiting, constipation, ileus, elevations of aspartate aminotransferase (AST) and alkaline phosphatase, hyperbilirubinemia, and ventricular bigeminy.
Conclusion: DEHSPM given as a SC injection is overall well tolerated at lower doses, but significant toxicities were observed at the 37.5mg/m2/day dose level. MTD was established at 25 mg/m2/day but further investigation with this study drug is not recommended secondary to the potential for neurotoxicities and hepatic damage as a result of cumulative doses.