PD0084430: a non-nucleoside inhibitor of human cytomegalovirus replication in vitro.
Human cytomegalovirus (HCMV) is a major opportunistic pathogen in immunocompromised individuals. Current therapies target viral DNA replication and accumulate mutations that yield cross-resistance among the approved drugs. A novel, non-nucleoside inhibitor of HCMV replication, PD0084430, was identified in a screening assay using the HCMV beta-galactosidase recombinant RC256. The EC(50) for PD0084430 by inhibition of beta-galactosidase production is 1+/-0.7 microM. This antiviral activity was confirmed by yield reduction and plaque reduction assays using HCMV strain AD169. The TC(50) of PD0084430 as measured by (4C)thymidine incorporation is approximately 30 microM and by XTT is approximately 90 microM. The TC(50) for inhibition of cellular proliferation is approximately 20 microM. Time of addition experiments displayed a similar drop in efficacy for both PD0084430 and GCV when added after the onset of viral DNA replication. The transcomplementation assay for viral DNA replication, using a transfected ori(Lyt) containing plasmid, confirmed that viral DNA synthesis was inhibited at the same concentrations that showed antiviral activity. Western blots showed no apparent block of immediate early or early gene expression. Two ganciclovir (GCV) resistant isolates of HCMV tested showed no cross-resistance to PD0084430. These data suggested a potentially promising novel compound that inhibited HCMV at or before viral DNA replication. However, in vivo testing in mice dosed either orally or intraperitoneally showed rapid glucuronidation on the -OH group. SAR studies on this backbone showed that the -OH group was essential for the antiviral activity in vitro.
Meyer
A L
AL
Department of Infectious Diseases, Pfizer Global Research and Development, Ann Arbor, MI 48105, USA. annette.meyers@pfizer.com
Bruening
E E
EE
Dunkle
W E
WE
Booth
R J
RJ
Steinbaugh
B A
BA
Vara Prasad
J V
JV
D000818:Animals; D000998:Antiviral Agents / Q000009:adverse effects / Q000737:chemistry* / Q000494:pharmacology* / Q000627:therapeutic use; D015153:Blotting, Western; D002082:Butylamines / Q000009:adverse effects / Q000737:chemistry* / Q000494:pharmacology* / Q000627:therapeutic use; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D003587:Cytomegalovirus / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D004261:DNA Replication / Q000187:drug effects; D004279:DNA, Viral / Q000096:biosynthesis; D024882:Drug Resistance, Viral; D005347:Fibroblasts; D015774:Ganciclovir / Q000494:pharmacology; D005816:Genetic Complementation Test; D006801:Humans; D051379:Mice; D010636:Phenols / Q000009:adverse effects / Q000737:chemistry* / Q000494:pharmacology* / Q000627:therapeutic use; D014176:Protein Biosynthesis / Q000187:drug effects; D012367:RNA, Viral / Q000096:biosynthesis; D013329:Structure-Activity Relationship; D010948:Viral Plaque Assay; D014779:Virus Replication / Q000187:drug effects*; D001616:beta-Galactosidase / Q000235:genetics
D000998:Antiviral Agents; D002082:Butylamines; D004279:DNA, Viral; C452340:PD 0084430; D010636:Phenols; D012367:RNA, Viral; D001616:beta-Galactosidase; D015774:Ganciclovir