Inhibition of dengue virus by an ester prodrug of an adenosine analog.
Dengue virus (DENV) is the most prevalent mosquito-borne viral pathogen that infects humans. Neither a vaccine nor an antiviral therapy is currently available for DENV. Here, we report an adenosine nucleoside prodrug that potently inhibits DENV replication both in cell culture and in a DENV mouse model. NITD449 (2'-C-acetylene-7-deaza-7-carbamoyladenosine) was initially identified as a parental compound that inhibits all four serotypes of DENV with low cytotoxicity. However, in vivo pharmacokinetic studies indicated that NITD449 had a low level of exposure in plasma when dosed orally. To increase the oral bioavailability, we covalently linked isobutyric acids to the 3'- and 5'-hydroxyl groups of ribose via ester linkage to NITD449, leading to the prodrug NITD203 (3',5'-O-diisobutyryl-2'-C-acetylene-7-deaza-7-carbamoyl-adenosin). Pharmacokinetic analysis showed that upon oral dosing of the prodrug, NITD203 was readily converted to NITD449, resulting in improved exposure of the parental compound in plasma in both mouse and rat. In DENV-infected AG129 mice, oral dosing of the prodrug at 25 mg/kg of body weight reduced peak viremia by 30-fold. Antiviral spectrum analysis showed that NITD203 inhibited various flaviviruses (DENV, yellow fever virus, and West Nile virus) and hepatitis C virus but not Chikungunya virus (an alphavirus). Mode-of-action analysis, using a luciferase-reporting replicon, indicated that NITD203 inhibited DENV RNA synthesis. Although NITD203 exhibited potent in vitro and in vivo efficacies, the compound could not reach a satisfactory no-observable-adverse-effect level (NOAEL) in a 2-week in vivo toxicity study. Nevertheless, our results demonstrate that a prodrug approach using a nucleoside analog could potentially be developed for flavivirus antiviral therapy.
Novartis Institute for Tropical Diseases, 10 Biopolis Road, #05-01 Chromos, Singapore 138670, Singapore.
Yen-Liang
YL
Chen
Zheng
Z
Yin
Suresh B
SB
Lakshminarayana
Min
M
Qing
Wouter
W
Schul
Jeyaraj
J
Duraiswamy
Ravinder Reddi
RR
Kondreddi
Anne
A
Goh
Hao Ying
HY
Xu
Andy
A
Yip
Boping
B
Liu
Margaret
M
Weaver
Veronique
V
Dartois
Thomas H
TH
Keller
Pei-Yong
PY
Shi
D000241:Adenosine / Q000031:analogs & derivatives* / Q000493:pharmacokinetics / Q000494:pharmacology / Q000627:therapeutic use; D000818:Animals; D000998:Antiviral Agents / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology* / Q000627:therapeutic use; D002460:Cell Line; D045744:Cell Line, Tumor; D002522:Chlorocebus aethiops; D003715:Dengue / Q000188:drug therapy* / Q000821:virology; D003716:Dengue Virus / Q000187:drug effects*; D004847:Epithelial Cells / Q000821:virology; D004952:Esters / Q000737:chemistry; D006801:Humans; D051379:Mice; D011355:Prodrugs / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology* / Q000627:therapeutic use; D051381:Rats; D014709:Vero Cells; D014779:Virus Replication / Q000187:drug effects*
D000998:Antiviral Agents; D004952:Esters; D011355:Prodrugs; D000241:Adenosine