Aurexis^® is being developed for the treatment, in combination with antibiotics, of serious S. aureus bacteremia and related complications in hospitalized patients. S. aureus continues to be a major medical and public health problem, accounting for 14-16% of all hospital acquired infections, including an estimated 30,000 deaths each year. In addition, S. aureus bacteria continue to develop resistance to most of the commonly used antibiotics. In 2004 the US Centers for Disease Control and Prevention (CDC) reported that almost two-thirds of all S. aureus infections in the U.S. were due to methicillin-resistant S. aureus (MRSA). MRSA infections are more serious, and lead to longer hospital stays and more deaths.

Aurexis^® is a humanized monoclonal antibody with a high affinity and specificity to clumping factor A (ClfA), which is expressed by virtually all strains of S. aureus. ClfA is a cell surface fibrinogen binding protein that plays an important role in the initial adherence of bacteria to host tissues and implanted bio-materials - the first step in establishing infection. Pre-clinical studies have shown Aurexis® to be effective in preventing and treating S. aureus infections, including those caused by MRSA.

We have completed a number of clinical trials of Aurexis^® including a Phase IIa study in 60 patients with complicated S. aureus bacteremia, and Phase I studies in normal healthy volunteers and subjects with end-stage renal disease. In the subjects studied to date, Aurexis^® has generally been safe and well-tolerated.