Starpharma announced new results demonstrating the high level of protection afforded by VIRALEZETM antiviral nasal spray against the highly infectious SARS-CoV-2 Omicron variant in vivo in a well-established humanised mouse challenge model 1 of coronavirus infection. Challenge models are often used in viral diseases to assess the ability of a product to treat or prevent an infection. In this study, conducted at Scripps Research, 100% of animals treated with VIRALEZETM before and after Omicron virus challenge had no detectable virus in lung, trachea or nasal cavity up to four days after exposure.

Viral load in the lungs and trachea of these VIRALEZETM-treated animals was reduced by >99.999% compared with the virus levels in saline-treated animals when assessed seven days after viral challenge with SARS-CoV-2 Omicron. Notably, animals treated with VIRALEZETM before and after infection had no detectable Omicron virus in the blood at any stage of the study. These impressive results for VIRALEZETM were in contrast to control saline-treated animals, where 100% had high levels of virus detected in blood, lung, trachea and nasal cavity from as early as two days post-challenge.

Animals treated with VIRALEZETM only after intranasal viral SARS-CoV-2 Omicron challenge also exhibited >99.999% reduction of virus in the lungs and trachea seven days after infection compared with saline-treated animals. This finding is important because it suggests that even when VIRALEZETM is used after exposure to virus, it has potential to provide significant benefit. All VIRALEZETM-treated animals also exhibited a significant reduction in proinflammatory cytokines compared with saline-treated animals, indicating reduced severity of disease.

These new findings for VIRALEZETM indicate that it is highly effective in inactivating and blocking Omicron virus in vivo, resulting in reduced viral load exposure, and thereby preventing or significantly reducing infection. Furthermore, despite significant mutation of the SARS-CoV-2 virus, VIRALEZETM provided high levels of protection against the highly infectious Omicron variant. The results of this in vivo study are consistent with previous in vitro findings where VIRALEZETM has demonstrated high levels of activity against all SARS-CoV-2 variants tested to date, including the highly infectious Omicron, Delta, Alpha, Beta, and Gamma variants.

VIRALEZETM is a broad-spectrum antiviral nasal spray that has been developed by Starpharma to be applied in the nasal cavity to help reduce exposure to virus. These new data provide further in vivo validation that VIRALEZETM can block and inactivate virus in the nasal cavity, and suggest that VIRALEZETM could be used to help to protect from infection with respiratory viruses, including SARS-CoV-2, and potentially as post-exposure prophylaxis to reduce severity of viral respiratory disease. VIRALEZETM also has a potential role in future pandemic preparedness given that SPL7013 in VIRALEZETM has been shown to highly effectively block a broad spectrum of respiratory viruses, including pandemic-causing viruses, such as multiple variants of SARS-CoV-2, SARS-CoV, MERS-CoV, influenza A and B viruses, and respiratory syncytial virus (RSV) in vitro.