Flavivirus screening
Identify chemical series with broad-spectrum activity against flaviviruses
current phase of drug development




updated 12 Mar 2026
Flaviviruses are a family of viruses that cause a range of diseases of pandemic potential, including dengue, Zika, and West Nile viruses. Transmitted mostly by the bites of infected mosquitoes, flavivirus disease outbreaks can occur unexpectedly. Large outbreaks can place a major burden on public health systems and overwhelm hospitals. While they often present with only mild symptoms that resolve without treatment, flavivirus infections can progress to severe illness and death. Children, pregnant women, older adults, and people with weakened immune systems are particularly vulnerable to severe disease.
Conducted in partnership with Eisai Co., Japan, and Institut Pasteur Korea (IPK), the flavivirus screening project aims to discover compounds that inhibit viral replication in flaviviruses with a focus on targeting the NS3 helicase. The project involves screening a 20,000-compound Eisai proprietary collection against both dengue and Zika viruses. This library includes subsets enriched with compounds chosen through machine learning-driven docking and ligand-binding affinity predictions for DENV/ZIKV NS3 helicase, as well as another subset based on chemical diversity to maximize the chance of finding inhibitors that act through alternative targets.
Project updates
2025
High-throughput screening of all 20,000 compounds against both dengue and Zika viruses at a concentration of 10 µM were completed by IPK and all active compounds with dose-response assays were validated. A counter screen of the active hits using Eisai’s molecular beacon-based fluorescent helicase assay identified three distinct chemical series that inhibit NS3 helicase and suppress viral growth in both dengue and Zika cellular assays. These three series are undergoing further enrichment through additional analogue testing at IPK and Eisai and are being considered for advancement to the hit-to-lead phase.
- Eisai Co., Ltd., Japan
- Institut Pasteur Korea (IPK), Republic of Korea
- Eisai Co., Ltd.
- ,Japan
- Institut Pasteur Korea (IPK)
- ,Republic of Korea
- Institut Pasteur Korea (IPK), Republic of Korea
- Eisai Co., Ltd., Japan
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