Nabi Biopharmaceuticals Announces Altastaph(TM) Phase II Trial Results in Neonates Analysis Drives Development of Next Generation Product ROCKVILLE, Md., Nov. 17 /PRNewswire-FirstCall/ -- Nabi Biopharmaceuticals today announced Phase II clinical trial results for Altastaph(TM) [Staphylococcus aureus Immune Globulin Intravenous (Human)]. This Phase II trial was conducted in premature, low birth-weight babies (neonates). Altastaph is the company's polyclonal antibody for prevention and treatment of Staphylococcus aureus infections, which can afflict at-risk patients including those who do not have time or are too immune-compromised to respond to a vaccine to prevent infection. Phase II clinical trials are generally small studies, sized to evaluate safety and the body's reaction to the drug under development. Results from this trial in neonates have demonstrated that Altastaph was safe and exhibited a good pharmacokinetic profile, the primary endpoints of the trial. The antibody levels following administration of Altastaph were well above the targeted level of 80-100 mcg/ml, which is believed to be protective against infections in neonates. However, the incidence rate of S. aureus infections observed in the neonates was very low, only 3%, versus an expected rate of 5 to 7% based on published literature and recent clinical studies. As a result, the company is unable to make any inference about Altastaph's effect on infections in neonates, as only three infections were reported in each of the placebo and treated arms of the study. Altastaph Development Program and Milestones In order to maximize the clinical and commercial potential for Altastaph in preventing bacterial infections in neonates, Nabi Biopharmaceuticals plans to rapidly expand and advance its Altastaph development program. The company will focus its effort on its next generation Altastaph product that will be developed to prevent a majority (up to two-thirds) of bacterial infections observed in neonates (S. aureus Types 5, 8 and 336 and S. epidermidis). S. epidermidis, one of the most prevalent and dangerous bacteria to infect neonates, is a cause of significant illness and death. Already during the fourth quarter of 2004, Nabi Biopharmaceuticals has completed formulation of a clinical lot of its S. epidermidis vaccine that can also be used as a stimulating agent for this next generation Altastaph product. The company expects to complete formulation of its Type 336 S. aureus vaccine in the first quarter of 2005 and will conduct initial safety and immunogenicity studies with these vaccines in 2005. This will allow for the manufacture of a clinical lot of the next generation of Altastaph in the second half of 2005 to support further clinical studies in 2006. The Altastaph development program, including the timing and type of clinical studies, will be determined after consultation with regulators in the United States and Europe. Altastaph has been granted fast track designation in the United States for its use in preventing infection in neonates. "We are committed to the development of our novel antibody approach to prevent and treat deadly bacterial infections. We will continue to advance our work in neonates, recognizing the significant medical need in this very vulnerable patient population, while also defining other at-risk patient groups who could benefit from our approach," stated Thomas H. McLain, chairman, chief executive officer and president, Nabi Biopharmaceuticals. "The development program we have in place for this next generation product is important for many reasons. While our initial plan to begin Phase III clinical testing of Altastaph in 2005 will be delayed, we believe this next generation product will provide important advantages for physicians when compared to other similar products under development. By developing a product that can prevent both S. aureus and S. epidermidis infections, we will be in a unique position to help reduce illness, complications and death in at-risk patients. In addition, we plan to leverage the value of the patent portfolio we have built around our next generation programs." Henrik S. Rasmussen, M.D., Ph.D., senior vice president, clinical research, medical and regulatory affairs and project management, Nabi Biopharmaceuticals, stated, "By including antibodies to prevent infections due to S. epidermidis or S. aureus Type 336, we should be able to demonstrate the benefits from Altastaph therapy against a broader range of infections that are the cause of this challenging and unmet medical need. This next generation product is expected to provide protection from all the strains of S. aureus bacteria causing serious infection in neonates. The additional protection against S. epidermidis bacteria will also be very important because these infections are a significant cause of illness and death in these patients." About the Phase II Altastaph Study The Altastaph study was a Phase II, double-blinded, placebo-controlled trial conducted in 20 neonatal intensive care units across the United States. Half of the 200 very low birth-weight infants studied received two doses of Altastaph 14 days apart starting 3 to 7 days after birth and the other half were given placebo. The primary endpoints of the trial were to evaluate the safety and pharmacokinetics of Altastaph. About Altastaph Altastaph is a polyclonal antibody for the prevention and treatment of S. aureus infections, and is based on the same mechanism of action as StaphVAX. Altastaph, an orphan drug recently granted Fast Track Designation, is being developed for patients at immediate risk of infection or patients whose immune systems are too suppressed to respond to a vaccine, such as neonates, or premature babies. Premature babies are at great risk of S. aureus infections because of their poorly developed immune systems. Neonates contracting such an infection have a poor prognosis. In addition to the neonate indication, Altastaph is being studied in hospitalized adults with confirmed, persistent S. aureus bacteremia to observe whether resolution of these infections can be accelerated. Data from this trial, which will primarily monitor Altastaph's safety and pharmacokinetics, as well as any effect on S. aureus bacteremia, is expected by the end of 2004. About Hospital-acquired Gram-positive Infections in Neonates Hospital-acquired Gram-positive infections, such as S. aureus and S. epidermidis, represent a significant problem in low birth-weight neonates who have poorly developed immune systems. In addition, these infants are often hospitalized for prolonged periods in neonatal intensive care units during which time they may undergo invasive medical procedures that increase the risk of S. aureus, S. epidermidis and other bacterial infections. Gram- positive infections in neonates are serious and are associated with a substantial increase in illness and death. Even if these infants survive their infections, their hospital stays are often prolonged. The frequency of antibiotic resistant S. aureus infections continues to increase and now approaches 60% or more in some healthcare settings. The recent identification of resistance to vancomycin, widely determined to be the current antibiotic of last resort to treat S. aureus infections, has led to recognition that antibiotic therapy alone is not sufficient to address this significant and growing problem and that adjunctive approaches must be developed and evaluated. About Nabi Biopharmaceuticals Nabi Biopharmaceuticals applies its knowledge of the human immune system to commercialize and develop products that address serious, unmet medical needs. The company's focus is in the areas of infectious, autoimmune and addictive diseases. In addition to four marketed products (PhosLo(R), Nabi- HB(R), WinRho SDF(R), Aloprim(TM)), the company has several products in various stages of preclinical and clinical testing. Nabi Biopharmaceuticals has advanced StaphVAX(R) to Phase III clinical development. StaphVAX is designed to prevent the most dangerous and prevalent strains of Staphylococcus aureus bacterial infections. S. aureus bacteria are a major cause of hospital-acquired infections and are becoming increasingly resistant to antibiotics. The company's other products in development include Altastaph(TM), an antibody for prevention and treatment of S. aureus infections, currently in Phase II testing, NicVAX(TM), a vaccine to treat nicotine addiction, and Civacir(TM), an antibody for preventing hepatitis C virus re-infection in liver transplant patients. For additional information on Nabi Biopharmaceuticals, please visit our Website 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 possibility that our confirmatory Phase III clinical trial for StaphVAX or our plans to commercialize StaphVAX in the EU may not be successful; the possibility that we may not realize the value of our acquisition of PhosLo; the company's dependence upon third parties to manufacture its products; the company's ability to utilize the full capacity of its manufacturing facility; the impact on sales of Nabi-HB from patient treatment protocols and the number of liver transplants performed in HBV-positive patients; reliance on a small number of customers; 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 Annual Report on Form 10-K for the fiscal year ended December 27, 2003 filed with the Securities and Exchange Commission. DATASOURCE: Nabi Biopharmaceuticals CONTACT: Mark Soufleris, Vice President, Investor & Public Relations, +1-561-989-5800 Web site: http://www.nabi.com/

Copyright