PeptiDream develops novel macrocyclic peptide inhibitor for treatment of multiple influenza strains

PeptiDream Inc., a public Tokyo-based biopharmaceutical company ("PeptiDream")( TOKYO:4587) announced today, in collaboration with The Tokyo Metropolitan Institute of Medical Science ("Tokyo Metropolitan Institute") the discovery and development of a novel macrocyclic peptide inhibitor for the treatment of multiple influenza strains.

Tokyo Metropolitan Institute has been leading a broad-based discovery effort for novel treatments for influenza, funded by the Japanese government and initiated in 2008. PeptiDream joined the discovery consortium taking a peptide-based approach using PeptiDream's proprietary Peptide Discovery Platform System (PDPS) to identify novel macrocyclic peptide inhibitors for influenza.

Two marketed therapeutics, Relenza (GSK) and Tamiflu (Roche), inhibit the neuraminidase enzyme on the influenza virus surface, yet these therapeutics are only effective shortly after viral exposure and are less effective against newer influenza strains, thus there is immediate need for other more effective treatments with different mechanisms of action.

The partnership focused on the discovery of novel peptide inhibitors of the influenza hemagglutinin (HA) protein found on the surface of influenza viruses and responsible for the binding and entry of virus to cells. PeptiDream identified lead peptide candidate iHA-24 which exhibited high affinity and selectivity for the HA protein. In addition, the macrocyclic peptide was highly effective in preventing both viral infection and viral proliferation in both cell-based experiments and mouse-based animal studies, and was more effective than any commercially available treatments. Peptide iHA-24 also exhibited broad influenza strain efficacy against H1N1 (2009 pandemic strain), H5N1 (bird flu, SARS), and H2N2 strains.

In light of these breakthrough results, pre-clinical testing in cynomolgus monkeys is slated to begin in May 2014. Successful validation of efficacy will lead to the preparation of a complete preclinical development data package for investigational new drug (IND) application slated for 2015.