That’s an optimistic timetable: drug development typically takes 10 years. But Collier may well meet his goal because last year the U.S. Food and Drug Administration moved to speed approval of treatments that improve the nation’s readiness to respond to bioterrorism. Rather than undergoing the usual extensive preclinical animal testing and three-phase human trials to establish drug safety and efficacy, treatments such as Anacor’s, Fischetti’s, and PharmAthene’s will have only to demonstrate effectiveness in two different animal models and safety in one human trial.Improved vaccines are also critical. Current anthrax vaccines are safe and effective, but for full protection, recipients require six doses over 18 months, a delay that could be costly for military troops who will be the main beneficiaries of any new vaccines. But fast-acting vaccines could also allow civilians to live or work in contaminated areas after an attack. The anthrax spore is difficult to destroy: even now, the Washington, DC, postal facility that handled two contaminated letters in 2001 remains shut down.
In an effort to reduce both the number of doses and the time needed to protect people from anthrax, researchers at Frederick, MD-based DynPort Vaccine and Avant Immunotherapeutics in Needham, MA, have developed a vaccine they hope will induce protective antibodies more quickly. The current vaccine is basically a “soup” of bacterial cell parts; the new vaccine comprises only protective antigen, the same toxin subunit on which Collier’s treatment is based. This specificity should help avoid side effects while speeding the body’s immune response. Clinical trials started in October 2002.
Avant plans to go even further. It recently received a government subcontract to create a single-dose oral vaccine that will shield against both anthrax and plague, a flea-borne bacterial disease that could also be a bioweapon. Contracted through DynPort from the Defense Department’s Joint Vaccine Acquisition Program, the project’s costs may exceed $8 million over two years. “This isn’t just a research idea,” says Una S. Ryan, Avant’s president and CEO. “It’s pretty well down the development line.”
To start making this vaccine, Avant’s scientists have removed disease-causing genes from cholera and salmonella bacteria. They plan to insert genes that code for proteins made by anthrax- and plague-causing bacteria. The resulting proteins should prompt the body to produce disease-fighting antibodies. “You’ll get protection against cholera, anthrax, and plague with one swig-and-go,” says Ryan. Avant’s plans call for beginning human tests of this vaccine within two years, she adds.
Indeed, more effective vaccines and treatments for anthrax won’t be the only payoffs from the current surge of bioterror defense research. Anacor’s new antibiotics, for example, should work not only against anthrax and other bioweapons, but also against such common diseases as pneumonia and bacterial meningitis and staph infections. “All this money is not only going to be useful for biowarfare organisms,” Fischetti says. “It’s going to be a real shot in the arm for how we deal with infectious diseases.” But even without such medical windfalls, these new treatments for anthrax will help build much-needed defenses against this major bioterror threat.