Nabi Biopharmaceuticals Advances on StaphVAX Development Program

BOCA RATON, Fla. -- Nabi Biopharmaceuticals has continued to advance the development of StaphVAX (Staphylococcus aureus Polysaccharide Conjugate Vaccine) and today announced updates to its manufacturing and clinical trial plans. Currently in a confirmatory Phase III clinical trial, StaphVAX is the company's investigational vaccine that is designed to prevent Staphylococcus aureus blood stream infections.

Nabi Biopharmaceuticals continues to make progress toward the manufacture of StaphVAX consistency lots at Cambrex to support the license application with the European Union planned for the end of 2004. Capacity at Cambrex can support the launch of StaphVAX in Europe and the initial launch in the US. Recognizing that the peak forecasted demand for StaphVAX is expected to be substantially higher than the capacity at Cambrex, the company has decided to develop its own manufacturing capacity for StaphVAX. This will increase total vaccine manufacturing capacity and provide a second source of production for this important product. The company is evaluating the build-out of a vaccine manufacturing plant in an unused portion of its manufacturing facility in Boca Raton, Fla. This option would have the advantage of optimizing resource utilization at this facility. Simultaneously, the company is conducting a search for a suitable existing manufacturing facility close to Nabi Biopharmaceuticals' research and development location in Maryland. The decision between the two alternatives will be based primarily on cost and time-to-market adjusted for risk in both.

"Nabi Biopharmaceuticals is seeking to ensure that it is in a position to adequately supply commercial quantities of StaphVAX in a timely manner," stated Raafat E.F. Fahim, PhD, senior vice president of technical and production operations. "By working with a reliable contract manufacturer like Cambrex to produce the vaccine and, at the same time, developing our own facility to supplement the production of StaphVAX, we will be in a position to optimize the value of this critical strategic asset for the company."

As previously announced, Nabi Biopharmaceuticals intends to initially file for licensure of StaphVAX in the European Union with vaccine manufactured at the Cambrex facility before the end of 2004. If the license is granted in the European Union, a supplemental filing will be submitted for the company's manufacturing facility, allowing supply of StaphVAX from both facilities. For the US filing for the licensure of StaphVAX, the company intends to submit a license application by the end of 2005, based on both the Cambrex facility as well as Nabi's own manufacturing facility. This strategy will provide back-up supply of StaphVAX.

Nabi Biopharmaceuticals also announced that following recent discussions with the U.S. Food and Drug Administration (FDA), the company will increase the number of end-stage renal disease (ESRD) patients in the confirmatory Phase III trial of StaphVAX from 3,000 to 3,600. The decision to expand the sample size was made following additional dialogue with the FDA as to what would constitute a clinically meaningful effect in the context of the adverse event profile. The increase in trial size will strengthen trial's statistical power to demonstrate statistical significance with a clinical reduction of 50 percent or more in type 5 and type 8 Staph aureus infections through eight months post-vaccination. This is less than the 60 percent reduction rate used in the protocol for the previous Phase III trial.

For licensure in the U.S., Nabi Biopharmaceuticals' plan to file a Biologics License Application (BLA) with the FDA by the end of 2005 remains unchanged. The outside costs of the confirmatory Phase III trial are projected to total approximately $36 million and will be incurred from initiation of the trial in 2003 through its expected completion in the second half of 2005.

The primary efficacy endpoint of the Phase III trial, which has been discussed and agreed with the FDA, is a statistically significant reduction in type 5 and type 8 Staph aureus bacteremia through eight months post-vaccination. A booster dose will also be administered eight months following the initial vaccination. Vaccine immunogenicity and efficacy will continue to be evaluated for an additional four months as secondary trial endpoints. Consequently, all patients enrolled in the trial will be followed for at least 12 months in total. The trial will be conducted at up to 200 clinical trial sites and is being done in conjunction with three of the leading dialysis providers in the U.S., Gambro Healthcare, Inc, DaVita Clinical Research, and Fresenius Management Services. In addition, a number of academic sites will participate in the study.

Staph aureus is the most common cause of serious hospital-acquired bloodstream infections. Staphylococcal infections are difficult to treat because the bacteria that cause them are highly virulent and, in many cases, resistant to currently available antibiotics. This rise of antibiotic resistance has markedly curtailed options for treating Staph aureus infections.

According to the current estimates of the U.S. Centers for Disease Control and Prevention (CDC), more than two million patients in the US each year contract an infection as a result of exposure to a pathogen while receiving care in a hospital. 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.

Source: Nabi Biopharmaceuticals