isirv

A number of influenza antiviral agents are currently being evaluated in clinical trials:

Favipiravir (T-705), a Polymerase Inhibitor

Favipiravir targets the RNA polymerases of influenza viruses and some other RNA viruses. It is a potent inhibitor of human influenza A and B viruses, including strains that are resistant to currently available antivirals, such as oseltamivir and zanamivir, and avian influenza viruses including H5N1.  Clinical trials of the effectiveness of favipiravir against influenza A and B infections have been completed, and the results are being reviewed by Japanese authorities.

Peramivir

Approved for intravenous administration in Japan and Korea, peramivir is undergoing phase III trials in the USA to evaluate its safety and efficacy against influenza, as an intravenous formulation.

Laninamivir

Approved in Japan for single dose therapeutic use against influenza, laninamivir is undergoing phase III trials in the USA. 

DAS181 (Fludase), an inhibitor of virus attachment

DAS181 is a recombinant protein incorporating the catalytic domain of Actinomyces viscosus sialidase fused to the epithelia anchoring domain of human amphiregulin. It inhibits virus attachment by removing the terminal sialic acid receptors for influenza and parainfluenza viruses. It is currently being evaluated in phase II clinical trials in the USA.