With government backing, Human Genome Sciences Inc. has the go-ahead to continue development of its anthrax therapeutic.

The Rockville, Md.-based company was awarded a contract from the U.S. Department of Health and Human Services (HHS) that includes an initial $1.8 million testing phase and the opportunity to add large supplies of its monoclonal antibody, ABthrax, to the national stockpile under the Project BioShield Act of 2004. The first phase of the contract calls for HGS to provide 10 grams of ABthrax (raxibacumab) within the next two months for comparative in vitro and in vivo testing. Under the second phase, the government has one year to exercise its option to order up to 100,000 doses of ABthrax.

While HGS completed a number of animal studies, as well as Phase I safety data, more than a year ago, the company had to wait for a government contract before moving forward, said Jerry Parrott, vice president of corporate communications for HGS.

"We spent money, up to this point, at our own risk and out of our own pocket," he told BioWorld Today. But the costs to conduct further trials, as well as establish a manufacturing capability, were too high to proceed "without an agreement from the government to purchase" ABthrax.

"So we're certainly pleased about this step forward," Parrott added. The government has one year to exercise its option, and "when we have that decision, we'll be able to move forward expeditiously."

HGS has not disclosed an estimated value for the 100,000 doses of its drug, though other anthrax products have yielded profitable deals from anti-bioterror funding. The largest deal of late has been Brisbane, Calif.-based VaxGen Inc., which received an $878 million BioShield contract for developing rPA102, an anthrax vaccine composed of recombinant protective antigen that has fast-track status. In that deal, signed in November of last year, the government has ordered a total 25 million doses for 2006 and 50 million doses for 2007. HHS last year also agreed to include 5 million doses of the approved anthrax vaccine, BioThrax, by Lansing, Mich.-based BioPort Corp. (See BioWorld Today, Nov. 8, 2004.)

Along with the HGS deal, the U.S. government also recently awarded a similar two-phase contract to Toronto-based Cangene Corp., which will supply its anthrax immune globulin (AIG), a hyperimmune product, to HHS for preliminary efficacy testing. Based on the outcome of this testing, the government could choose to purchase between 10,000 and 100,000 doses over a period of three years.

Several other companies are working on products to prevent and treat anthrax. Elusys Therapeutics Inc., of Pine Brook, N.J., recently received $5.4 million in government funding for the development of Anthim, its antibody therapeutic to prevent and treat anthrax. That grant included $4.4 million from the National Institute of Allergy and Infectious Disease and $1 million from the Department of Defense. And PharmAthene Inc., of Annapolis, is partnering with Princeton, N.J.-based Medarex Inc. to develop a monoclonal antibody called Valortim.

ABthrax, an antibody to Bacillus anthracis, was developed by HGS using technology stemming from its collaboration with Cambridge Antibody Technology plc, of Cambridge, UK. While the drug has a prophylactic aspect, its attraction is its ability to treat bacterial toxins that have been released into a patient's system, Parrott said.

"There are vaccines that are aimed at prevention, and they play an important role," he said. "And then you've got antibiotics, which are designed to fight bacteria. The difficulty is that once the toxin complex is released from the bacteria, antibiotics can do no more good."

Therapeutics such as ABthrax are aimed at treating people who have "toxins loose in the body," he said. "There is a definite need for a therapy like this in the strategic national stockpile."

While awaiting a government contract for ABthrax, HGS has continued to advance its other clinical programs, including LymphoStat-B (belimumab), an antibody designed to inhibit the biological activity of B-lymphocyte stimulator. Earlier this year, LymphoStat-B met its primary endpoint in a Phase II trial in rheumatoid arthritis patients, and it has received fast-track designation as a treatment for systemic lupus erythematosus. The company's long-acting form of interferon alpha, Albuferon, has completed a Phase II study in patients with chronic hepatitis C who are na ve to interferon-alpha treatments. HGS also has ongoing programs in oncology and cardiovascular disease.

Shares of HGS (NASDAQ:HGSI) gained 47 cents Monday to close at $14.06.