Nabi Biopharmaceuticals announced that StaphVAX [Staphylococcus aureus Polysaccharide Conjugate Vaccine], which is currently in a confirmatory phase III clinical trial, has received fast track designation from the US FDA for the prevention of Staphylococcus aureus (S. aureus) bloodstream infections in end-stage renal (kidney) disease (ESRD) patients.
ESRD patients are at increased risk of contracting a S. aureus bloodstream infection due to the nature of their ongoing treatment. Nabi Biopharmaceuticals' novel vaccine technology, on which StaphVAX is based, is designed to stimulate the patient's immune system to build antibodies to the most common forms of S. aureus infections without the development of resistance, the company says in a release.
"Receiving fast track designation for StaphVAX from the FDA underscores the importance of addressing the significant unmet medical need related to Staphylococcus aureus bloodstream infections among ESRD patients," said Henrik Rasmussen, senior vice president of clinical, medical and regulatory affairs, Nabi Biopharmaceuticals.
"There are more than 300,000 dialysis patients in the United States and an additional 460,000 patients in other countries undergoing dialysis. And the number of patients on dialysis is expected to grow significantly over the next decade. Staphylococcus aureus infections are responsible for many illnesses and deaths among these patients, who present a particular challenge due to the invasive nature of their dialysis treatment. We look forward to working closely with the FDA to advance the development of StaphVAX and ultimately to provide this innovative new treatment option to these patients," Rasmussen added.
Dr. Rasmussen concluded, "We believe that both the patient and the healthcare system will benefit from preventing Staphylococcus aureus bloodstream infections with StaphVAX. The patient will avoid a devastating infection with a high incidence of mortality and illness; the health care system will avoid the high-cost of treating these infections in the hospital. We also believe using a cost effective vaccine that prevents staph aureus infections will help to slow the over-use of antibiotics and the associated rapid rise in antibiotic resistance."
In August 2004, the company completed enrolment in a double-blinded, placebo-controlled, randomized trial in 3,600 ESRD patients undergoing haemodialysis. This trial is designed to demonstrate that types 5 and 8 S. aureus infections will be reduced by 50 per cent or more through eight months in StaphVAX-treated patients. Patients will receive a booster dose of the vaccine at eight months, and the reduction in infections will be measured for four months after the booster injection as a secondary endpoint. The company plans to announce results from this trial in the second half of 2005 and to file a Biologics License Application for StaphVAX with the FDA by the end of 2005, the release says.
S. aureus is the most common cause of serious bloodstream infections in dialysis patients. 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 S. aureus infections.
According to data presented at the 2003 ICAAC meeting, six per cent of dialysis patients in the United States will contract an infection each year. Once introduced into the bloodstream, S. aureus can spread to the bones (osteomyelitis), to the inner lining of the heart and its valves (endocarditis), or cause abscesses in internal organs such as the lungs, liver and kidneys.
According to a study conducted at Duke University Medical Centre, the most recent and largest study of its kind, the mortality rate of those suffering from staph bacteria at 12 weeks was 24 per cent. All dialysis patients are at risk for infection regardless of the type of dialysis access or the colonization of bacteria in the nose.
Under the FDA Modernization Act of 1997, fast track regulations are designed to facilitate the development of products designed to treat serious or life-threatening diseases where an unmet medical need exists. Fast track regulations are also designed to expedite the review process for designated products, including the potential for companies to ask for priority review.