NexBio, Inc. announced today the publication "DAS181 Inhibits H5N1 Influenza Lung Virus Infection of Human Lung Tissues" in the September, 2009 issue of the journal Antimicrobial Agents and Chemotherapy (AAC).
DAS181 (Fludase((R))) is an investigational drug candidate in clinical development for Influenza-Like Illness. Unlike neuraminidase inhibitors (e.g. Tamiflu((R))), which target the virus, DAS181 works by inactivating the human host receptor for all influenza and para-influenza viruses tested so far including the current pandemic Novel H1N1 strain ("Swine Flu"). Previous preclinical studies conducted in collaboration with the Centers for Disease Control and Prevention have shown DAS181 to have significant prophylactic and therapeutic activity in an in vivo animal model for a highly virulent H5N1 (A/VN/1203/04) strain of influenza. The current published study, conducted in collaboration with the University of Hong Kong, examined for the first time the effects of DAS181 in human lung tissue and cells. DAS181 strongly inhibited H5N1 (A/VN/3046/2004) infection in human lung tissue and cells. The study also demonstrated that DAS181 effectively removes the two types of sialic acid (Sia) receptors to which influenza virus binds, thereby preventing both the invasion by virus into new cells and further replication where infection already exists.
The human lung tissue and cells described have been critical models for understanding the clinical pathogenesis of influenza, as people contain two types of receptors for influenza. While H5N1 preferentially binds to A2-3-linked Sia, Novel H1N1 preferentially binds to A2-6-linked Sia. DAS181 was shown in these studies to remove both the A2-6-linked and A2-3-linked types found in human respiratory tissue. Most importantly, virus was suppressed by inactivation of the entry receptors by DAS181 treatment.