Broad spectrum antiviral agents
Viruses are the causative agents of many debilitating infections, including major diseases which have killed millions. HIV, the virus which causes AIDS, continues to wreak havoc on the populations of third world countries, and influenza is a major cause of death worldwide, through localised epidemics and global pandemics. On average, influenza is responsible for up to 300,000 hospitalisations per year and between 20,000 and 40,000 deaths per year in the US. There is also the threat of major pandemics, such as the 1918 influenza strain which is estimated to have killed more than 40 million people world wide, more than the total fatalities of the First World War. The prospect of the development of recent bird flu isolates into strains capable of infecting humans (such as H5N1), has prompted governments to draw up emergency infection control measures and stock-pile antiviral medicines. Deadly and highly-infective viruses like SARS and Ebola also represent an emerging threat.
Despite the huge contribution of modern molecular biology to the understanding of viral infection and replication, very few effective antiviral treatments are available. These tend to be narrow in spectrum, targeting functions specific to one class of viruses only, and are susceptible to the problems of development of resistant viral strains. This is in contrast to antibacterial and antifungal drugs, which tend to have a much broader spectrum. Consequently, the antiviral strategies of public health departments tend to focus on vaccines, which have the problem that their effectiveness can be limited by the continual emergence of new viral variants which escape the protection of the vaccine. There is therefore a huge unmet medical need for new broad-spectrum antivirals against a wide range of viruses, and with a mode of action not susceptible to the rapid development of resistant viral strains.
Novacta Therapeutics is developing lantibiotics as broad-spectrum antiviral agents with a unique and novel mechanism of interfering with virus infection. Their mode of action involves the response of host cells to viral attack, and they have the potential to block virus infection and proliferation at multiple targets. Because they interact with host cell components rather than acting directly on viral functions, lantibiotics have less potential for the development of resistant viral strains, and are less influenced by antigenic drift in viral populations. Lantibiotics have been shown to have activity against influenza, Herpes Simplex Virus and Human CytomegaloVirus. Novacta Therapeutics is using its proprietary lantibiotic engineering technology to develop new compounds with improved activity against influenza and other viral targets.
