Human Genome Sciences Receives Fast-Track Product Designation For ABthrax for Prevention and Treatment of Anthrax Infections

ROCKVILLE, Md. -- Human Genome Sciences, Inc. announced today that it has received a Fast-Track Product designation from the U.S. Food and Drug Administration (FDA) for ABthrax (PA mAb), a novel drug for the prevention and treatment of anthrax infections.

The FDA established its Fast Track Drug Development Programs in response to the Food and Drug Administration Modernization Act of 1997, which authorized the FDA to take actions to facilitate the development and expedite the review of new drugs designated by the FDA as demonstrating the potential to address serious unmet medical needs. For a new drug to be designated a Fast Track Product, the condition it is designed to treat must be serious or life-threatening, and must represent an unmet medical need. The FDA also must determine that the drug has the potential to address the unmet medical need and that the development program is designed to evaluate this potential.

As previously announced, Human Genome Sciences has initiated a Phase 1 placebo-controlled, dose-escalation clinical trial of ABthrax in healthy adult volunteers to evaluate the safety, tolerability and pharmacokinetics of ABthrax. The trial will evaluate different dose levels of intramuscularly administered ABthrax and intravenously administered ABthrax. (1) The ABthrax used for preclinical and clinical studies is produced in the Company's manufacturing facilities in Rockville, Md.

Sally D. Bolmer, PhD, RAC, said, "We are pleased that the FDA has decided to grant Fast Track status to ABthrax for use in preventing and treating anthrax infections. We look forward to the opportunity for close cooperation with the FDA as we continue the development of this novel antibody drug."

Craig A. Rosen, PhD, president of research and development, said, "We believe that ABthrax has the potential to provide significant protection against anthrax infections when given prophylactically, and may lessen the natural progression of anthrax infection and increase survival if given as a post-exposure treatment. ABthrax also may prevent and treat infections by antibiotic-resistant strains of anthrax."

William A. Haseltine, PhD, chairman and CEO, said, "We are pleased to receive the FDA's Fast Track Product designation for ABthrax. We believe that ABthrax has the potential to play an important role in the prevention and treatment of anthrax infections."

ABthrax is a human monoclonal antibody to Bacillus anthracis protective antigen that was discovered and developed by Human Genome Sciences. ABthrax has been shown to be effective in protecting against anthrax in multiple experimental models in animals. A single dose of ABthrax increases survival significantly in both rabbit and nonhuman primate models of inhalational anthrax. (2) Full results of these studies will be disclosed in upcoming scientific meetings and publications as appropriate. Large-scale development and manufacture of ABthrax is dependent on government funding either under existing authority or under proposed Project Bioshield legislation.

Under the Bioterrorism Act of 2002, the FDA specified the evidence required to demonstrate the efficacy of new drug and biological products used to counter biological agents, when traditional efficacy studies in humans are not feasible. (3) According to the guidelines set forth in the Bioterrorism Act, successful studies in relevant animal models will be considered sufficient to establish efficacy for licensure and marketing approval. ABthrax has been demonstrated to be effective in preventing the lethal effects of anthrax infection in two relevant models, rabbits and nonhuman primates. According to the guidelines, clinical trials will be required to establish safety, tolerability, and pharmacology, but not efficacy.

For more information about the FDA's Fast Track Drug Development Programs, visit www.fda.gov.

References:

1. (HGSI Press Release) Human Genome Sciences Receives FDA Clearance to

Initiate Human Trial of Novel Drug to Prevent or Treat Anthrax

Infections. June 25, 2003.

2. (HGSI Press Release) Human Genome Sciences Develops New Means to

Prevent and Treat Anthrax Infections. March 18, 2003.

3. Public Health Security And Bioterrorism Preparedness And Response Act

Of 2002: Section 123.

http://www.fda.gov/oc/bioterrorism/PL107-188.html.

Source: Human Genome Sciences, Inc.