HHS evaluates proposals for new anthrax vaccine

;

Aug 12, 2008 (CIDRAP News) – Two Maryland pharmaceutical companies recently announced that they have submitted proposals to produce and deliver at least 25 million doses of a next-generation anthrax vaccine to the nation's Strategic National Stockpile.

Both companies—Emergent BioSolutions, based in Rockville, and PharmAthene, based in Annapolis—announced in Jul 31 statements that they submitted responses to a request for proposal (RFP) from the US Department of Health and Human Services (HHS). The RFP was issued in February and seeks 25 million doses of recombinant protective antigen (rPA) anthrax vaccine, based on a key anthrax protein, with a shelf life of at least 2 years.

Federal officials didn't say if any other companies submitted proposals to produce an rPA anthrax vaccine for HHS. Robin Robinson, director of the HHS Biomedical Advanced Research and Development Authority (BARDA), said the agency received multiple offers and that they appear promising, according to a report yesterday in the Baltimore Sun.

Robinson told the Sun that BARDA expects to allocate $1.5 billion toward adding anthrax vaccines to the national stockpile. The government has said it wants to boost the national anthrax vaccine stockpile from 18.2 million doses to enough to protect 300 million, the report said.

Feds spell out vaccine request
The contract would require companies to secure Food and Drug Administration approval for the rPA anthrax vaccine. Initially, the vaccine would be used for pre-exposure prophylaxis in adults, with a future label extension to allow postexposure prophylaxis alongside antibiotics.

Federal officials said they expect to award the contract to one or more companies, based on available funding, by late September.

Federal officials have been seeking a new vaccine formulation that can provide immunity in three doses, rather than the six doses required for the licensed vaccine, and that will cause fewer side effects.

The anthrax vaccine currently in the national stockpile, Anthrax Vaccine Adsorbed (AVA), was developed in the 1950s and is produced by Emergent BioSolutions under the brand name BioThrax. The product, required for US military personnel serving in high-risk areas such as the Middle East, is given in six doses over 18 months, followed by an annual booster.

A number of service members have reported serious side effects from the vaccine, and some sued to shelve the program. However, in late February a US district court judge dismissed the suit.

The latest federal call for a new version of the anthrax vaccine came 4 months after the Government Accountability Office (GAO), the investigative arm of Congress, criticized previous attempts to secure a second-generation anthrax vaccine as premature, unrealistic, and vague regarding its intended use.

In 2007, HHS withdrew an $877.5 million contract to VaxGen, a South San Francisco, Calif., biotechnology company, after it missed some of its development milestones. The contract required VaxGen to produce 75 million doses of the rPA anthrax vaccine, enough to immunize 25 million people.

In May, VaxGen sold its experimental anthrax vaccine to its competitor, Emergent BioSolutions, according to previous reports. One month earlier, PharmAthene acquired an rPA anthrax vaccine candidate that was developed by Avecia, a biotechnology company based in the United Kingdom. The National Institute for Allergy and Infectious Diseases (NIAID) has supported both candidates with research grants.

Phase 2 studies complete
Emergent BioSolutions said its vaccine candidate is a reformulated and more stable version of the rPA 102 vaccine that was originally developed at the US Army Medical Research Institute of Infectious Diseases. In its statement, the company said phase 2 studies of rPA have been completed.

James Jackson, senior vice president and chief executive officer (CEO) of Emergent BioSolutions, said in the statement its analytical and nonclinical data support the vaccine's stability improvements: "We believe that the current formulation will meet the US government's stability requirements for an rPA vaccine," he said.

The company said it would produce the vaccine at its new manufacturing facility in Lansing, Mich.

PharmAthene said its new anthrax vaccine consists of rPA adsorbed into alhydrogel and packaged as a filled syringe for intramuscular injection. In its statement, the company said preclinical studies suggest that two or three doses administered several weeks produce an immune response that requires annual boosters.

It said phase 1 and 2 studies involving 700 human subjects suggest that its rPA anthrax vaccine is safe and well tolerated and produces a protective immune response.

David P. Wright, PharmAthene's president and CEO, said the competition for the HHS contract is stiff, according to the Sun report. "This will not be a cakewalk for us. We have very strong competitors, but I believe, with the caliber of staff we have, that we will be successful at the end of the day in producing for this country the vaccine we need," he told the Sun.

See also:

Jul 31 Emergent BioSolutions press release

Jul 31 PharmAthene press release

HHS request for proposal listing

Oct 31, 2007, CIDRAP News story "GAO critiques anthrax vaccine procurement, management"

Jul 29 CIDRAP News story "Anthrax vaccine maker wins NIAID grants"

Newsletter Sign-up

Get news & practices.

Sign up now»

OUR UNDERWRITERS

Unrestricted financial support provided by

Bentson Foundation 3M United Health Foundation Gilead Become an underwriter»