Pharmacokinetics and tissue and tumor exposure of CP-31398,  a p53-stabilizing agent, in rats.
OBJECTIVE
CP-31398 (N0-[2-[(E)-2-(4-methoxyphenyl)ethenyl] quinazolin-4-yl]-N,N-dimethylpropane-1,3-diamine hydrochloride) is one of the new class of agents that can stabilize the DNA-binding domain of p53 and thereby maintain the activity of p53 as a tumor suppressor and transcription factor. Through its activity as a p53 stabilizer, CP-31398 demonstrates significant cancer preventive and therapeutic activity in several in vivo animal models. The objective of the current study was to describe the pharmacokinetic profile and tissue distribution of this novel agent following intravenous or oral (gavage and dietary) administration.


METHODS
CP-31398 was administered to male CD and F344 rats as a single intravenous bolus dose or by daily oral gavage dosing. Male F344 rats also received drug as an ad libitum dietary supplement. Plasma, liver, skin, colon, and colon tumor samples were collected after oral dosing. Concentrations of CP-31398 in plasma and tissue samples were analyzed using LC–MS/MS, and the resultant data were subjected to a non-compartmental pharmacokinetic analysis.


RESULTS
Bioavailability (12–32%), elimination half-life (14–20 h), clearance (4.2–4.8 l/h/kg), and volume of distribution (70–82 l/kg) were determined. Tissue levels of CP-31398 after oral (gavage or diet) administration were several orders of magnitude higher than were corresponding plasma concentrations; CP-31398 levels were especially high in colon and liver. Levels of CP-31398 in tissues were higher after gavage dosing than after dietary administration.


CONCLUSIONS
CP-31398 is bioavailable and has a relatively long elimination half-life, which supports the achievement of plasma steady-state levels with a once daily dosing regimen. CP-31398 exhibits a dramatically high volume of distribution, which is consistent with its tissue concentrations being much higher than corresponding plasma levels. It is accumulated in colon tumor tissues, albeit at lower concentrations than found in liver, skin, and colon.
Chemopreventive Agent Development Research Group, Division of Cancer Prevention, National Cancer Institute, 6130 Executive Blvd., Rm. 2116, Bethesda, MD 20892, USA. kapetani@mail.nih.gov
Izet M
IM
Kapetanovic
Miguel
M
Muzzio
David L
DL
McCormick
Thomas N
TN
Thompson
William D
WD
Johnson
Thomas L
TL
Horn
Altaf
A
Mohammed
Chinthalapally V
CV
Rao
Levy
L
Kopelovich
D000284:Administration, Oral; D000818:Animals; D001682:Biological Availability; D002853:Chromatography, Liquid; D003106:Colon / Q000378:metabolism*; D006207:Half-Life; D007275:Injections, Intravenous; D008099:Liver / Q000378:metabolism*; D008297:Male; D011743:Pyrimidines / Q000008:administration & dosage / Q000493:pharmacokinetics*; D051381:Rats; D011916:Rats, Inbred F344; D053719:Tandem Mass Spectrometry; D014018:Tissue Distribution; D016159:Tumor Suppressor Protein p53 / Q000187:drug effects* / Q000378:metabolism
D011743:Pyrimidines; D016159:Tumor Suppressor Protein p53; C402665:CP 31398