Pharmacokinetics of the Protease Inhibitor KNI-272 in Plasma and Cerebrospinal Fluid in Nonhuman Primates after Intravenous Dosing and in Human Immunodeficiency Virus-Infected Children after Intravenous and Oral Dosing

Autor: Mueller, Brigitta U., Anderson, Barry D., Farley, Maureen Q., Murphy, Robert, Zuckerman, Judy, Jarosinski, Paul, Godwin, Karen, McCully, Cindy L., Mitsuya, Hiroaki, Pizzo, Philip A., Balis, Frank M.
Zdroj: Antimicrobial Agents and Chemotherapy; July 1998, Vol. 42 Issue: 7 p1815-1818, 4p
Abstrakt: ABSTRACTKNI-272 is a human immunodeficiency virus (HIV) protease inhibitor with potent activity in vitro. We studied the pharmacokinetics of KNI-272 in the plasma and cerebrospinal fluid (CSF) of a nonhuman primate model and after intravenous and oral administration to children with HIV infection. Plasma and CSF were sampled over 24 h after the administration of an intravenous dose of 50 mg of KNI-272 per kg of body weight (approximately 1,000 mg/m2) to three nonhuman primates. The pharmacokinetics of KNI-272 were also studied in 18 children (9 males and 9 females; median age, 9.4 years) enrolled in a phase I trial of four dose levels of KNI-272 (100, 200, 330, and 500 mg/m2per dose given four times daily). The plasma concentration-time profile of KNI-272 in the nonhuman primate model was characterized by considerable interanimal variability and rapid elimination (clearance, 2.5 liters/h/kg; terminal half-life, 0.54 h). The level of drug exposure achieved in CSF, as measured by the area under the KNI-272 concentration-time curve, was only 1% of that achieved in plasma. The pharmacokinetics of KNI-272 in children were characterized by rapid elimination (clearance, 276 ml/min/m2; terminal half-life, 0.44 h), limited (12%) and apparently saturable bioavailability, and limited distribution (volume of distribution at steady state, 0.11 liter/kg). The concentrations in plasma were maintained above a concentration that is active in vitro for less than half of the 6-h dosing interval. There was no significant increase in CD4 cell counts or decrease in p24 antigen or HIV RNA levels. The pharmacokinetic profile of KNI-272 may limit the drug’s efficacy in vivo. It appears that KNI-272 will play a limited role in the treatment of HIV-infected children.
Databáze: Supplemental Index