Developing compounds against viral capsids is an attractive therapeutic strategy in theory, but has yet to work in practice because of the difficulty of inhibiting protein-protein interactions. Novira Therapeutics Inc. believes it has the right medicinal chemistry capabilities to develop small molecules that prevent capsid formation in HBV and HIV.

The capsid is a protein shell that forms around a virus to protect it during passage from one cell to another. "They do not have obvious binding sites, so there was a perception that they were not tractable targets," according to co-founder and CSO Osvaldo Flores.