Evaxion Biotech A/S announce the successful conclusion of a series of large non-rodent animal infection studies, testing antigens from Evaxion?s preclinical EVX-B1 vaccine candidate against Staphylococcus aureus (S. aureus). In the animal studies, the EVX-B1 antigens significantly reduced disease burden. Currently, the two companies are engaged in discussions regarding the path forward.

There is no S. aureus vaccine available for human use. This pathogen can cause infections of multiple organs and tissues, which can be profoundly severe or even fatal. Most at risk are individuals with chronic conditions and patients undergoing surgeries.

Also, the presence of antibiotic-resistant S. aureus is limiting available treatment options. The Centers for Disease Control and Prevention (CDC) has reported 120,000 bloodstream infections associated with S. aureus in the US annually. Three separate studies in large, non-rodent animals were conducted with the following conclusions: The EVX-B1 vaccine antigens significantly reduced S. aureus bacterial burden in a surgical site infection model; Induction of meaningful antigen-specific antibody titers in all vaccinated animals; The ability of the antigens to induce a protective immune response in the animals when being colonized with S. aureus mimicking the human situation; Ability of the immune blood to neutralize clinically relevant S. aureus in a whole blood killing assay, holding promise for translational assay readout in early clinical development.