Novel SARS-CoV-2 neutralising antibodies identified
IONTAS and FairJourney Biologics have announced the identification of neutralising antibodies, which bind to multiple emerging SARS-CoV-2 variants.
The results, generated from a combination of phage display technology and B-cell receptor repertoire sequencing of hospitalised COVID-19 patients, have identified potent neutralising antibodies with distinct mechanisms of action. Based on this approach, the Company has developed a panel of therapeutic candidates.
SARS-CoV-2 virus enters the body as a result of the viral spike protein binding to the ACE2 protein on the surface of lung cells. This interaction is driven by a small region of the spike protein and the majority of antibodies currently undergoing clinical trial bind to this site. However, this site has changed in some of the emerging viral variants, reducing or abolishing the effect of some clinical candidates. Drug candidate antibodies developed by IONTAS to this site have been shown to retain binding to the emerging variants.
An alternative approach for tackling variants is to target alternative regions of the virus that have a greater degree of conservation, making escape variants less likely. GSK/VIR Biotechnology recently announced a successful Phase 3 trial of such an antibody, VIR-7831, which binds to a region of the spike protein that is highly conserved between SARS-CoV-2 and SARS-CoV-1. VIR-7831 has shown an 85% reduction in hospitalisation and death during the COMET-ICE clinical trial. The partnership is now seeking Emergency Use Authorisation in the USA and other regions.
A subset of the IONTAS antibodies show a similar functionality to VIR-7831, by binding to sites conserved both in the recently emerging SARS-CoV-2 variants as well as to the more distantly related SARS-CoV-1 virus.