By Lisa Seachrist
Interim results from a pivotal trial testing the ability of the Nabi-StaphVAX vaccine to prevent gram-positive bacterial infections in high-risk patients showed the product is on track to have a statistically significant end result that can be used to file a new drug application with the FDA.
Nabi, of Boca Raton, Fla., is testing a single dose of Nabi-StaphVAX in a Phase III trial against a placebo injection in 1,800 end-stage renal disease patients who are dependent on dialysis. An outside data safety and monitoring board that conducted the analysis determined the study would support a filing should the current data trends continue.
"We are very happy about the results so far," said Tanina Frouge, director of investor relations for Nabi. "The trend is toward statistical significance for the primary endpoint of this trial and that is very good news."
Nabi-StaphVAX is a capsular polysaccharide vaccine designed to prevent infections by the gram-positive bacterium Staphylococcus aureus. For most people, S. aureus is an innocuous resident of their skin and nasal cavities. However, the bacteria can become deadly when it gains access to the bloodstream via a surgical incision, intravenous line or catheter.
Two million Americans will acquire a nosocomial (hospital-based) infection each year and between 60,000 and 80,000 of these patients will die. S. aureus is responsible for about 15 percent of these infections, which can affect bone and other organs.
In the pivotal trial, Nabi focused on patients likely to develop blood-borne infections with S. aureus as a result of the intravenous lines used during dialysis. Patients in the trial received either a single injection of Nabi-StaphVAX or a placebo injection at the outset of the trial. They are being followed for a year to determine whether Nabi-StaphVAX decreases the risk for these infections.
"We dosed our last patient in June and will complete the trial in June 2000," Frouge said. "If the trend continues and we have positive results, we intend to file with FDA before the end of 2000."
Nabi is developing a second-generation gram-positive vaccine that could battle the main perpetrators in 80 percent of all nosocomial infections: Staphylococcus aureus, Staphylococcus epidermidis and Enterococcus. Nabi-AltaStaph, an antibody product, is being developed as a potential therapy for patients who already have a gram-positive blood infection.
"We think these products will have utility in preventing and treating this problem," Frouge said.
Nabi's stock (NASDAQ: NABI) closed at $5.00 Wednesday, up 37.5 cents per share.