Three fractions of v38 AMF-1 were tested against H5N1, the virus responsible for causing avian influenza (bird flu), and all showed excellent potency and selectivity at inhibiting H5N1 uptake and viral infections.
The results come from the US arm of an ongoing, multi-national project jointly sponsored by PRB and Lee’s Pharmaceuticals. In the first arm of the project, researchers at the Chinese University of Hong Kong found v38 AMF-1 to be effective against a variety of pathogens, including the virus responsible for causing severe acute respiratory syndrome (SARS). It was subsequently shown that v38 AMF-1 inhibits the 3C-like protease (3CLpro), a crucial part of the SARS virus life cycle.
In the second arm of the project, v38 AMF-1 was shown to inhibit H5N1 in chicken embryos. 100% of chicken embryos inoculated with H5N1 and treated with v38 AMF-1 survived while all of those not receiving v38 AMF-1 died within hours.
“The finding that v38 AMF-1 blocks H5N1 virus attachment is extremely important as it demonstrates v38 AMF-1 works much differently than the neuraminidase inhibitors Tamiflu (oseltamivir) and Relenza (zanamivir),” said Dr Charles Hensley, chairman and CEO of PRB Pharmaceuticals. “Tamiflu can only work once the virus has already entered and multiplied inside the cells. This drug’s mode of action is less than ideal which may explain why Tamiflu is only marginally effective as a treatment for influenza in humans. v38 AMF-1 keeps the virus out of the cells in the first place.”
v38 AMF-1 is one component of Vira 38, PRB Pharmaceuticals’ influenza medicine. Vira 38 is a comprehensive medicine that attacks the virus at multiple points of its life cycle such as viral attachment, uncoating, replication and release. This new paradigm for antiviral medicines generates therapies with greater efficacy and lower incidence of drug resistance.