Development of Galleria mellonella (wax moth) larvae as a model for snakebite envenoming

Snakebite envenoming (SBE) annually kills >100,000 people worldwide, and 4-fold more suffer life-altering morbidity. Antivenom, the only specific treatment, requires preclinical models to assess efficacy and safety as an essential part of the manufacturing and regulatory process. In accordance with the World Health Organization (WHO) ‘Guidelines for the production, control and regulation of antivenom immunoglobulins’, the only validated assays to determine the potential clinical effectiveness of an antivenom are preclinical mouse models. These procedures are rated ‘severe’ in the UK and EU, are low-throughput and require high animal numbers. Galleria mellonella (wax moth) models have gained momentum as a replacement for vertebrate models in the last decade, mainly focused on infectious diseases. Here we present the development of a Galleria model for SBE with the aim of providing a readily accessible (low-cost, low-skill) and standardised non-vertebrate alternative model for both research and commercial use. Our pilot data from a wide panel of snake venoms demonstrates that Galleria envenoming pathology is comparable to mammalian envenoming – i.e. coagulopathic venoms impair the clotting function of both mammalian blood and Galleria hemolymph, and neurotoxic venoms cause rapid paralysis in mammals and Galleria. Beyond a venom profiling tool inclusive of LD50 assessments, to date we have shown this model can be used to access therapeutic efficacy (ED50s) for Echis ocellatus venom neutralisation by both EchiTAbG and a small molecule SVMP inhibitor (marimastat).