7-Deaza-7-fluoro modification confers on 4'-cyano-nucleosides potent activity against entecavir/adefovir-resistant HBV variants and favorable safety

• Type of Material: Article
• Authors: Sanae Hayashi, Nagoya City University; Nobuyo Higashi-Kuwata, National Center for Global Health & Medicine Research Institute, Tokyo; Debananda Das, National Cancer Institute, Bethesda; Kota Tomaya, Yamasa Corporation; Kohei Yamada, Yamasa Corporation; Shuko Murakami, Nagoya City University; David J Venzon, National Cancer Institute, Bethesda; Shin-Ichiro Hattori, Nagoya City University; Masanori Isogawa, Nagoya City University; Stefan Sarafianos, Emory University; H Mitsuya, Natl Ctr Global Hlth & Med Res Inst; Yasuhito Tanaka, Nagoya City University
• Language: English
• Date: 2020-04-01
• Publisher: ELSEVIER
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2020 Elsevier B.V. All rights reserved.
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1016/j.antiviral.2020.104744
• Title of Journal or Parent Work: ANTIVIRAL RESEARCH
• Volume: 176
• Start Page: 104744
• End Page: 104744
• Grant/Funding Information: The present work was supported in part by the Intramural Research Program of the Center for Cancer Research, National Cancer Institute, National Institutes of Health (R01AI121315 for HM); a grant for Development of Novel Drugs for Treating HBV infection and HIV-1 Infection/AIDS from Japan Agency for Medical Research and Development (AMED)(JP19fk0310113 and JP18fk041001, respectively, for HM, JP19fk0310113 for YT); grants from Japan Society for the Promotion of Sciences; and a grant from National Center for Global Health and Medicine Research Institute (HM). This study utilized the high-performance computational capabilities of the Biowulf Linux cluster at the National Institutes of Health, Bethesda, MD (https://hpc.nih.gov).
• Keywords: Entecavir; Drug resistance; Virology; HBV; Anti-HBV drugs; Pharmacology & Pharmacy; Nucleoside/nucleotide reverse transcriptase inhibitors; INFECTION; DNA; ANTI-HIV ACTIVITY; NUCLEOSIDE ANALOGS; TENOFOVIR; HEPATITIS-B; Adefovir; Life Sciences & Biomedicine; INHIBITORS; Science & Technology

Abstract

We designed, synthesized and identified a novel nucleoside derivative, 4′-C-cyano-7-deaza-7-fluoro-2′-deoxyadenosine (CdFA), which exerts potent anti-HBV activity (IC50 ~26 nM) with favorable hepatocytotoxicity (CC50 ~56 μM). Southern blot analysis using wild-type HBV (HBVWT)-encoding-plasmid-transfected HepG2 cells revealed that CdFA efficiently suppresses the production of HBVWT (IC50 = 153.7 nM), entecavir (ETV)-resistant HBV carrying L180M/S202G/M204V substitutions (HBVETVR; IC50 = 373.2 nM), and adefovir dipivoxil (ADV)-resistant HBV carrying A181T/N236T substitutions (HBVADVR; IC50=192.6 nM), whereas ETV and ADV were less potent against HBVETVR and HBVADVR (IC50: >1,000 and 4,022.5 nM, respectively). Once-daily peroral administration of CdFA to human-liver-chimeric mice over 14 days (1 mg/kg/day) comparably blocked HBVWT and HBVETVR viremia by 0.7 and 1.2 logs, respectively, without significant changes in body-weight or serum human-albumin levels, although ETV only slightly suppressed HBVETVR viremia (CdFA vs ETV; p = 0.032). Molecular modeling suggested that ETV-TP has good nonpolar interactions with HBVWT reverse transcriptase (RTWT)'s Met204 and Asp205, while CdFA-TP fails to interact with Met204, in line with the relatively inferior activity against HBVWT of CdFA compared to ETV (IC50: 0.026 versus 0.003 nM). In contrast, the 4′-cyano of CdFA-TP forms good nonpolar contacts with RTWT's Leu180 and RTETVR's Met180, while ETV-TP loses interactions with RTETVR's Met180, explaining in part why ETV is less potent against HBVETVR than CdFA. The present results show that CdFA exerts potent activity against HBVWT, HBVETVR and HBVADVR with enhanced safety and that 7-deaza-7-fluoro modification confers potent activity against drug-resistant HBV variants and favorable safety, shedding light to further design more potent and safer anti-HBV nucleoside analogs.