News Release

Staph aureus bacteremia in ESRD patients associated with substantial illness and higher costs

Pharmacoeconomics studies presented at ICAAC

Peer-Reviewed Publication

Kureczka/Martin Associates

Chicago, Illinois, September 17, 2003 – Substantial treatment costs and illness are suffered by end-stage kidney (renal) disease (ESRD) patients who develop Staph aureus blood stream infections (bacteremias), according to new pharmacoeconomic studies presented this week at the 43rd annual Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC) in Chicago, IL. Moreover, ESRD patients with Staph aureus bacteremia that are caused by bacteria that are resistant to the antibiotic methicillin (MRSA) are at a higher risk of dying and incur higher treatment costs than patients with bacteremias caused by methicillin sensitive Staph aureus (MSSA). The two studies, sponsored by Nabi Biopharmaceuticals, Inc. (Nasdaq: NABI) and executed by Duke University Medical Center, were presented by investigators from Duke University Medical Center and Duke Clinical Research Institute, Durham, NC.

"Staph aureus is the most common cause of serious hospital-acquired infections, including bloodstream infections, and their increased resistance to many different antibiotics is a growing source of concern in the medical community," said Henrik S. Rasmussen, M.D., Ph.D., Nabi Biopharmaceuticals senior vice president, clinical, medical and regulatory affairs. "Despite its clinical significance, the economic impact of Staph aureus bacteremia has not been fully appreciated. The two studies presented at ICAAC clearly describe the clinical outcomes, associated with health care resource utilization and infection-associated costs of Staph aureus bacteremia among a large group of prospectively identified, hemodialysis-dependent patients. The full data from these studies have been submitted for publication."

"Clearly, these studies point out the tremendous challenges that continue to face healthcare professionals trying to manage Staph aureus bacteremias in ESRD patients," continued Dr. Rasmussen. "These results underscore the need for a new approach such as Nabi Biopharmaceuticals' StaphVAX® (Staphylococcus aureus Polysaccharide Conjugate Vaccine) vaccine for preventing these infections with the potential to significantly reduce the tremendous costs associated with them."

The first study reported on 210 hemodialysis-dependent patients with Staph aureus bacteremia treated at Duke University Hospital. These patients experienced significant complications due to their infections. The mean initial hospitalization costs almost doubled for patients with omplicated Staph aureus bacteremias such as endocarditis and osteomyelitis versus bacteremias without these complications ($32,462 compared to $17,011, p=0.002). The mean cost of treating Staph aureus bacteremia, including readmissions and outpatient costs, was $24,034 per episode.

The second study reported on the resources, costs and mortality among 143 dialysis-dependent patients hospitalized with Staph aureus bacteremia. In this study, ESRD patients with bacteremia caused by MRSA proved to be at a higher risk of dying within 12 weeks and incurred higher costs than patients with bacteremia caused by MSSA. MRSA infections are responsible for up to 60% of Staph aureus infections in the U.S. today.

Patients with ESRD are at high-risk of developing Staph aureus bacteremias partly because they are immune-compromised due to their debilitating underlying disease and also because the need for access to the vascular system for dialysis puts them at increased risk of infection. This patient population is projected to continue to grow due to the increasing number of patients suffering from the complications of diabetes which can often result in the loss of kidney function.

Nabi Biopharmaceuticals is planning to initiate a confirmatory Phase III clinical trial with StaphVAX® in the United States in approximately 3,000 ESRD patients during the 4th quarter of 2003. The primary endpoint of the trial will be the incidence of bacteremia caused by types 5 and 8 Staph aureus through 8 months post-vaccination.

This endpoint correlates with the peak efficacy point in the first StaphVAX Phase III trial which was published in the February 14, 2002 issue of The New England Journal of Medicine. In an attempt to sustain efficacy beyond 8 months in these patients at chronic risk for Staph aureus infections, the confirmatory Phase III trial will also include a booster vaccination at 8 months. The vaccine's ability to generate antibodies, efficacy and safety will continue to be followed for up to six months following the booster dose. Secondary endpoints for this trial will also include the cost of Staph aureus bacteremia infections that occur during the study.

About Staph aureus Infections

Staph aureus is the most common cause of serious hospital-acquired infections, including bloodstream infections. Community-acquired staph infections are also of growing concern as they continue to increase in prevalence. Hospitals and other healthcare settings worldwide face unprecedented crises from the rapid emergence and dissemination of antibiotic-resistant bacteria, according to the National Institutes of Health and the Center for Disease Control. Strains of drug-resistant staph are found in most hospitals, often leaving vancomycin as the antibiotic of last resort for treating patients with these infections. With vancomycin-resistant strains of Staph aureus now appearing globally, many experts believe that a vaccine to prevent these infections may offer the best long-term solution.

According to the U.S. Centers for Disease Control and Prevention (CDC), more than two million patients in the U.S. each year contract an infection as a result of exposure while receiving healthcare in a hospital. Staph aureus is among the most common causes of these hospital-acquired infections and is reportedly associated with a death rate of 10 percent to 30 percent because of its capacity to cause serious complications and its resistance to many different antibiotics.

Staph aureus can spread from the blood (bacteremia), to the bones (osteomyelitis), or the inner lining of the heart and its valves (endocarditis), or cause abscesses in internal organs such as the lungs, liver and kidneys.

People most at risk for these infections are surgical patients, trauma or burn victims, newborns whose immune systems are not yet developed, and patients with chronic illnesses such as diabetes, cancer, or lung or kidney diseases. People whose immune systems are suppressed due to disease, chemotherapy, or radiation therapy are generally more susceptible to these bacterial infections. ESRD patients on hemodialysis represent a particular high-risk group due to a combination of their compromised immune system and the need for repeated access to their blood system several times a week.

About Nabi Biopharmaceuticals

Nabi Biopharmaceuticals discovers, develops, manufactures and markets products that power the immune system to help people with serious, unmet medical needs. The company has a broad product portfolio and significant research capabilities focused on developing and commercializing novel vaccines and antibody-based therapies that prevent and treat infectious, autoimmune and addictive diseases, such as Staphylococcus aureus and hepatitis infections, immune thrombocytopenia purpura ("ITP"), and nicotine addiction. Nabi Biopharmaceuticals has several products in clinical trials, as well as five marketed products, including Nabi-HBÒ [Hepatitis B Immune Globulin (Human)], for the prevention of hepatitis B infections upon acute exposure; WinRho SDFÒ [Rho (D) Immune Globulin Intravenous (Human)], for the treatment of acute, chronic and HIV-related ITP; and PhosLoÒ (Calcium Acetate) for the control of hyperphosphatemia in end stage renal (kidney) failure patients. The company is headquartered in Boca Raton, Florida, with principal R&D offices and laboratories in Rockville, Maryland. Additional information about Nabi Biopharmaceuticals may be obtained on the company's web site at http://www.nabi.com.

This press release contains forward-looking statements that reflect the company's current expectations regarding future events. Any such forward-looking statements are not guarantees of future performance and involve significant risks and uncertainties. Actual results may differ significantly from those in the forward-looking statements as a result of any number of factors, including, but not limited to, risks relating to the costs of research and development; the company's dependence upon third parties to manufacture its products; the impact of current industry supply and demand factors on the company and its products; the ability of the company to meet its contractual obligations; the future sales growth prospects for the company's biopharmaceutical products; and the company's ability to obtain regulatory approval for its products in the U.S. or abroad or to successfully develop, manufacture and market its products.

These factors are more fully discussed in the company's most recent Form 10-K filed with the Securities and Exchange Commission and any subsequent filings.

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Mark Soufleris
Vice President, Investor & Public Relations
561-989-5800

Joan Kureczka
Kureczka/Martin Associates
415-821-2413


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