Discovery and Optimization of First-in-Class Furopyrimidine-Based Inhibitors of Henipaviruses

Henipaviruses such as Nipah (NiV) and Hendra (HeV) are zoonotic pathogens that cause severe and often fatal respiratory illness and encephalitis in both animals and humans. These viruses exhibit high transmissibility and pandemic potential, a situation made worse by the absence of appropriate pharmaceutical countermeasures. To address this deficit, we conducted a hit-to-lead optimization campaign based on hit 1 identified through high-throughput screening against recombinant Cedar virus (rCedV), a nonpathogenic surrogate for NiV and HeV. This effort yielded a focused library of analogs that were initially screened against rCedV, with promising candidates subsequently validated against authentic NiV and HeV. Among these, analog 46 demonstrated superior in vitro metabolic stability and pharmacokinetic properties relative to hit 1 and is now positioned for in vivo efficacy evaluation. Concurrently, the mechanism of action of these first-in-class furopyrimidine-based antiviral agents was probed through time-of-addition assays, escape mutation analysis, and preliminary in silico modeling.