Cap-dependent endonuclease-IN-26, a potent inhibitor of cap-dependent endonuclease (CEN) with an IC50 of 286 nM, exhibits significant antiviral activity against a broad spectrum of influenza A and B strains [1].

Cap-dependent endonuclease-IN-26 (compound 2v) demonstrates a broad antiviral spectrum effective against various influenza strains, including H1N1 (rgA/WSN/33, rgA/WSN/33-NA/H274Y, A/PR/8/34), H3N2 (A/Victoria/3/75, A/HongKong/8/68), oseltamivir-resistant, clinically isolated strains, and influenza B (Hong Kong/5/72, Maryland/1/59), with EC50 values of 165.1 nM, 80.4 nM, 183.0 nM, 828.8 nM, 301.5 nM, 124.3 nM, and 176.0 nM, respectively [1].

In rats, Cap-dependent endonuclease-IN-26 (compound 2v) demonstrates favorable in vivo clearance rates at 10.9 mL/min/kg [1]. Administered intravenously at doses ranging from 0.08-10 mg/kg once daily for a day in a mouse influenza B (B/Maryland/1/59) model, compound 2v exhibits dose-dependent efficacy in an immediate treatment scenario [1].