Nabi Biopharmaceuticals granted Staphylococcus Antigen and Vaccine patent

Nabi Biopharmaceuticals has announced that it has been granted U.S. Patent No. 6,936,258 entitled "Staphylococcus Antigen and Vaccine" by the U.S. Patent and Trademark Office for the composition of a strategically important glycoprotein-based antigen (GP-1) associated with three Staphylococcal strains: S. epidermidis, S. haemolyticus and S. hominis.

These strains are part of the increasing problem of hospital-acquired infections. Addressing them represents a strategically important component of Nabi Biopharmaceuticals' commercial franchise focused on treating and preventing the broadest array of Staphylococcal bacteria across the largest cross section of patients.

The patent covers the following: the composition of the antigen, the use of the antigen as a vaccine, and the methods for obtaining and detecting the antigen. Nabi Biopharmaceuticals also currently holds a patent for another S. epidermidis antigen, PS-1, which covers the use of the antigen as a vaccine. The PS-1 antigen is found on approximately 80 percent of all S. epidermidis strains. Nabi Biopharmaceuticals initiated a Phase I clinical trial with this vaccine earlier in 2005.

One unique aspect of the GP-1 antigen claimed in the patent is that it prevents adherence of S. epidermidis to catheters. Hence, this antigen will be developed to help diminish the risk of infections associated with implanted devices, in particular, indwelling catheters. Patients with chronic indwelling catheters are at high risk for S. epidermidis infections, as the catheter provides a port of entry for the bacteria, which often lives on the skin of the patient and healthcare personnel. S. epidermidis is responsible for 50 to 70 percent of all catheter-related infections. Additionally, S. epidermidis and other similar infections represent approximately 20 to 25 percent of all Gram-positive nosocomial (hospital-acquired) infections.

Nabi Biopharmaceuticals' hospital-acquired infections franchise has the potential to not only help the broadest range of patients, most at risk of contracting prevalent and often deadly bacterial infections, but to also address the growing problem of antibiotic resistance. Antibiotics have been the traditional method for treating these infections, but are becoming less effective against these bacteria. A vaccine such as Nabi Biopharmaceuticals' StaphVAX (Staphylococcus aureus Polysaccharide Conjugate Vaccine) has the potential to circumvent this problem because it is designed to safely empower the body's own immune system to recognize the bacteria and destroy it before causing harm to the patient. A vaccine based on the GP-1 antigen against these three Staphylococcal strains would convey the same potential advantages.

"The protection afforded these antigens is an important step in advancing the significant commercial opportunity inherent in our hospital-acquired infections franchise," stated Thomas H. McLain, chairman, chief executive officer and president, Nabi Biopharmaceuticals. "The award of this patent is part of our strategy to protect and expand this franchise, and it significantly strengthens the company's intellectual property position in this area."

Mr. McLain added, "At Nabi Biopharmaceuticals we are building what will be the first comprehensive and holistic approach in the prevention and treatment of dangerous and often life-threatening hospital-acquired infections. We are focused not only on developing this franchise to address the most prevalent pathogens, but also to protect the greatest number of patients at risk for those infections."