Pharmacokinetics of N-aspartyl chlorin e6 in cancer patients

We examined the pharmacokinetics of the photosensitizer N-aspartyl chlorin e6 in a group of cancer patients. While the drug persisted in plasma for as long as six weeks, there was no evidence of fluorescent NPe6 metabolites during this interval. Kinetics of drug elimination from plasma were consistent with a 2-compartment model with half-lives of approximately 9 hr (57%) and 134 hr (43%). The drug was bound to plasma albumin+other heavy proteins (65%) > HDL (35%) > > LDL (1-2%). These relative values did not change for as long as 21 days after drug administration. The long persistence of NPe6 in plasma was not associated with extended skin photosensitization.