ABSTRACT
The biotransformation, CYP reaction phenotyping, the impact of CYP inhibitors and enzyme kinetics of 3-cyanomethyl-4-methyl-DCK (CMDCK), a new anti-HIV preclinical candidate belonging to DCK analogs, were investigated in human intestinal microsomes and recombinant cytochrome P450 (CYP) enzymes. CMDCK (4 micromol L(-1)) was incubated with a panel of rCYP enzymes (CYP1A2, 2C9, 2C19, 2D6 and 3A4) in vitro. The remaining parent drug in incubates was quantitatively analyzed by a LC-MS method. CYP3A4 was identified as the principal CYP isoenzyme responsible for its metabolism in intestinal microsomes. The major metabolic pathway of CMDCK was oxidation and a number of oxidative metabolites were screened with LC-MS. The Km, Vmax, CLint and T1/2 of CMDCK obtained from human intestinal microsome were 45.6 micromol L(-1), 0.33 micromol L(-1) min(-1), 12.1 mL min(-1) kg(-1) and 25.7 min, respectively. Intestinal clearance of CMDCK was estimated from in vitro data to be 3.3 mL min(-1) kg(-1), and was almost equal to the intestinal blood flow rate (4.6 mL min(-1) kg(-1)). The selective CYP3A4 inhibitors, ketoconazole, troleandomycin and ritonavir demonstrated significant inhibitory effects on CMDCK intestinal metabolism, which suggested that co-administration of CMDCK with potent CYP3A inhibitors, such as ritonavir, might decrease its intestinal metabolic clearance and subsequently improve its bioavailability in body.
Subject(s)
Humans , Anti-HIV Agents , Metabolism , Pharmacokinetics , Biological Availability , Bridged Bicyclo Compounds, Heterocyclic , Metabolism , Pharmacokinetics , Coumarins , Metabolism , Pharmacokinetics , Cytochrome P-450 CYP3A , Cytochrome P-450 CYP3A Inhibitors , Intestines , Metabolism , Ketoconazole , Pharmacology , Metabolic Clearance Rate , Microsomes , Metabolism , Ritonavir , Pharmacology , Troleandomycin , PharmacologyABSTRACT
The new HIV-1 NNRTI drug Etravirine (TMC125) and a promising drug candidate Rilpivirine (TMC278) in phase III clinical trial are compounds belonging to the diarylpyrimidine (DAPY) family. They are extremely high potent against both wild-type and many drug-resistant HIV-1 strains, providing new hope for HIV-infected patients who fail to use current drugs due to the emergence of drug-resistant HIV mutants. The discovery and development of DAPY derivatives as next-generation NNRTI drugs depend on multidisciplinary coordination and their success has encouraged new researches to explore more next-generation NNRTIs with new scaffolds. This review described the story of discovery and development of DAPY derivatives as next-generation NNRTIs and related progress.