Evaxion & Undisclosed Collaborator Announce Encouraging Results for Vaccine Antigens Against Staphylococcus Aureus Infection


Evaxion Biotech A/S recently announced 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.

Birgitte Rønø, Chief Scientific Officer at Evaxion, said “We are very thrilled about the encouraging data and believe that our EVX-B1 vaccine antigens hold the potential for efficacy in human trials – a milestone that previous vaccine attempts have failed to achieve.”

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

The EVX-B1 antigens have been designed using Evaxion’s AI-Immunology platform. AI-Immunology has enabled the identification of novel Staphylococcus aureus antigens, paving the way for developing a vaccine with the potential for broad protection against clinically relevant S. aureus strains.

According to the CDC, S. aureus colonizes about 30% of the human population without causing any harm. However, S. aureus can also cause infections that can be serious or even fatal. One of the most serious conditions is bacteremia or sepsis, where the bacteria spread to the bloodstream. This pathogen can also cause pneumonia, endocarditis and osteomyelitis (infection of the lung air sacs, heart valves and bone, respectively). Most at risk are those with chronic conditions such as diabetes, patients in intensive care units, patients who have undergone certain types of surgeries and patients with medical devices inserted in their bodies. The presence of antibiotic-resistant S. aureus, particularly Methicillin-resistant S. aureus (MRSA), further limits treatment options. In the US, nearly 120,000 bloodstream infections and 20,000 deaths were associated with S. aureus in 2017.

Evaxion Biotech A/S is a pioneering TechBio company based upon its AI platform, AI-Immunology. Evaxion’s proprietary and scalable AI prediction models harness the power of artificial intelligence to decode the human immune system and develop novel immunotherapies for cancer, bacterial diseases, and viral infections. Based upon AI-Immunology, Evaxion has developed a clinical-stage oncology pipeline of novel personalized vaccines and a preclinical infectious disease pipeline in bacterial and viral diseases with high unmet medical needs. Evaxion is committed to transforming patients’ lives by providing innovative and targeted treatment options. For more information, visit our website.