Development and application of a radioimmunoassay for pepleomycin.

A rapid sensitive radioimmunoassay for pepleomycin (PM) has been developed using an antiserum produced in a sheep in response to a bovine serum albumin-drug conjugate. Radioiodinated PM was prepared using Iodogen. The assay was reproducible with a limit of detection in plasma of 200 ng/liter. The antiserum does not cross-react with bleomycin or with a number of unrelated drugs. Pharmacokinetic studies using the assay were carried out in three patients who received a short iv infusion of 5 mg/m2 of PM. The drug disappeared from the plasma with an elimination half-life of approximately 3 hours.