Nabi Biopharmaceuticals Successfully Completes StaphVAX Immunogenicity Study

ROCKVILLE, Md. -- Nabi Biopharmaceuticals today announced the successful completion of an immunogenicity trial using material from the lot of StaphVAX (Staphylococcus aureus Polysaccharide Conjugate Vaccine) intended for use in a confirmatory Phase III trial later this year. The immunogenicity trial was an open-label, single-dose study in 40 healthy volunteers that evaluated the antibody response to StaphVAX.

"The results from this trial are an important proof that we can successfully transfer production of StaphVAX to a contract manufacturing facility. This study demonstrated that this lot of vaccine generates antibody levels that are at least as good as those generated from vaccine manufactured in our R&D pilot plant and used in our previous Phase III clinical trial," said Henrik S. Rasmussen, MD, PhD, senior vice president, clinical, medical and regulatory affairs. "In addition, the results from this immunogenicity trial continued to demonstrate an excellent safety and tolerability profile for StaphVAX. While completing this study, we also made very good progress putting in place the necessary logistics for executing the 3,000 patient confirmatory Phase III trial and we remain on track to initiate the trial in the early part of the fourth quarter."

The confirmatory StaphVAX Phase III trial will be conducted in the United States in approximately 3,000 end-stage renal disease (ESRD) patients. ESRD patients represent the same patient population that was previously studied successfully and reported on in the Feb. 14, 2002 issue of The New England Journal of Medicine. The primary endpoint of the confirmatory Phase III trial will be a statistically significant reduction of S. aureus bacteremia caused by types 5 and 8 S. aureus through eight months post-vaccination, the peak efficacy point in the first Phase III trial. The trial will include a booster vaccination at eight months, and the investigators will continue to follow the vaccine's ability to generate antibodies, efficacy and safety for up to six months following the booster dose.

S. aureus is the most common cause of serious hospital-acquired infections, including bloodstream infections. Community-acquired staph infections are also of growing concern. 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 S. 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 2 million patients in the U.S. each year contract an infection as a result of exposure while receiving healthcare in a hospital. S. 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. S. 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.

Source: Nabi Biopharmaceuticals