MALONATO-(1,2 DIAMINOCYCLOHEXANE) PLATINUM (MP) is a new platinum analog currently undergoing phase I clinical trials Using flameless alomie absorption spectrophalometry, the pharmacokinties of MP were studied at live dosage levels. The drug was given as a prolonged intravennus infusion, lasting from 6 to 24 bours, Feak plasma platinum concentrations (Pt) were seen at the end of the infusion, and ranged from 1.1 μ/ml when 3 mg/kg was given to 14–20.3 μg/ml at the 24-mg/kg level. Following completion of the infusion. a prolonged Tβ (mean 63.5 hours) was noted. The percentage of free total platinum was high (90–95%) at the beginning of the infusion but fell rapidly, to only 15–21% at the end of the 24-hour infusions, Urinary excretion accounted for 16–37.5% of the total administered dose MP appears to have several pharmacokinetic features in common with cisplatin: rapid binding to protein, a prolonged terminal phase half-life involving primarily bound platinum, and incomplete excretion by the kidney
a The Solid Tumor and Developmental Chemotherapy Service and the Physiology Renal Laboratory. Department of Medicine. Memorial Sloan Kettering Cancer Center. Cornell University Medical College. New York. New York.
b The Institut de Canceroiogie et D. Immunogenetique Hospital Paul-Broiuse. Villejuif. France.