NABI ANNOUNCES INITIATION OF NEW STAPHVAX IMMUNOGENICITY STUDY IN ORTHOPEDIC SURGERY PATIENTS

Nabi Biopharmaceuticals has initiated its U.S. StaphVAX (Staphylococcus aureus Polysaccharide Conjugate Vaccine) immunogenicity study in orthopedic surgery patients with implanted devices.

The study is a double-blinded, placebo-controlled trial that will evaluate a total of 120 patients undergoing orthopedic surgery that involves the implantation of synthetic material (such as hip or knee replacement). Results from this study are expected to be available by the end of the third quarter of 2005.

The objective of this study is to evaluate safety and antibody levels in these patients over a six-month period. The company expects this study will demonstrate that after vaccination with StaphVAX, this large at-risk patient group can achieve antibody levels equal to or greater than the levels proven to be protective in immune-compromised end-stage renal disease patients. Patients undergoing orthopedic surgery are at high risk of developing S. aureus bacteremia and subsequent infections because of the invasive nature of this surgery.