Zanamivir and oseltamivir, specific inhibitors of influenza virus neuraminidase, have significantly different characteristics in resistance studies. In both cases resistance is known to arise through mutations in either the hemagglutinin or neuraminidase surface proteins. A new inhibitor under development by Biocryst Pharmaceuticals, BCX-1812, has both a guanidino group, as in zanamivir, and a bulky hydrophobic group, as in oseltamivir. Using influenza A/NWS/Tern/Australia/G70C/75 (H1N9), neuraminidase variants E119G and R292K have previously been selected by different inhibitors. The sensitivity of these variants to BCX-1812 has now been measured and found in both cases to be intermediate between those of zanamivir and oseltamivir. In addition, the X-ray crystal structures of the complexes of BCX-1812 with the wild type and the two mutant neuraminidases were determined. The ligand is bound in an identical manner in each structure, with a rearrangement of the side chain of E276 from its ligand-free position. A structural explanation of the mechanism of resistance of BCX-1812, relative to zanamivir and oseltamivir in particular, is provided.
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http://dx.doi.org/10.1021/jm010528u | DOI Listing |
J Infect Chemother
December 2024
Japan Physicians Association, Tokyo, Japan; Ricerca Clinica Co., Fukuoka, Japan.
Introduction: To assess the susceptibility of epidemic influenza viruses to the four most used neuraminidase inhibitors (NAIs) during the 2023-24 influenza season in Japan, we measured the 50% inhibitory concentration (IC) of oseltamivir, peramivir, zanamivir, and laninamivir in virus isolates from the sample of 100 patients.
Methods: Viral isolation was done using specimens obtained before and after treatment, with the type/subtype determined by RT-PCR using type- and subtype-specific primers. IC values were determined by a neuraminidase inhibition assay using a fluorescent substrate.
Fukushima J Med Sci
December 2024
Department of Pediatrics, Fukushima Medical University.
Since 2000, rapid antigen detection kits and anti-influenza drugs have been used for the early diagnosis and treatment of influenza in Japan, respectively. The main drugs available in clinical practice are the neuraminidase inhibitors oseltamivir, zanamivir, laninamivir, and peramivir, as well as the cap-dependent endonuclease inhibitor baloxavir marboxil. Antiviral therapy with neuraminidase inhibitors has been practiced for many years, especially in Japan; it can shorten the febrile period and reduce complications.
View Article and Find Full Text PDFAdv Ther
December 2024
School of Pharmaceutical Sciences, Ohu University, 31-1 Misumido, Tomita-machi, Koriyama, Fukushima, 963-8611, Japan.
Introduction: Vaccines can prevent influenza (flu) infections and are cost-effective for society and healthcare. However, the cost-effectiveness of post-exposure prophylaxis as a follow-up strategy is unclear. This study aims to evaluate the cost utility of post-exposure prophylaxis and treatment strategies with neuraminidase inhibitors and a cap-dependent endonuclease inhibitor for flu infections from the perspective of healthcare costs in Japan.
View Article and Find Full Text PDFAnn Intern Med
December 2024
University of Nebraska Medical Center, Omaha, Nebraska, USA (S.J.S., A.C.K.).
Antiviral Res
December 2024
Department of Biochemistry, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka-shi, Shizuoka, 422-8526, Japan.
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