Valortim (MDX-1303) is an investigational fully human antibody created using Medarex’ UltiMAb human antibody development system that targets the Bacillus anthracis protective antigen.
The investigational antibody is designed to target a protein component known as the anthrax protective antigen of the lethal toxin complex produced by the bacterium. The anthrax protective antigen is believed to initiate the onset of the illness by attaching to cells in the infected person, and then is believed to facilitate the entry of additional destructive toxins into the cells. Valortim is designed to target anthrax protective antigen and protect the cells from damage by the anthrax toxins.
US orphan drug designation will provide important benefits to Valortim’s developers, including eligibility for a special seven-year period of market exclusivity upon approval, potential R&D grant funding, and assistance with clinical trial protocol review.
“Despite aggressive antibiotic therapy and supportive care, the anthrax attacks of 2001 resulted in a mortality rate of nearly 50%, illustrating the urgent need for more effective anthrax therapeutics,” remarked David Wright, president and CEO of PharmAthene. “Our receipt of orphan drug designation for Valortim and, earlier this year, fast track designation, should facilitate a more streamlined development process through more frequent dialogue with the FDA.”
Preclinical studies suggest that Valortim has the potential to provide significant protection against anthrax infection when administered prophylactically, and also may increase survival when administered therapeutically.
Valortim is currently being evaluated in a phase I dose-escalation clinical trial to evaluate the safety, tolerability, immunogenicity, and pharmacokinetics of a single dose of Valortim administered intravenously or intramuscularly in healthy volunteers. Results from this trial are anticipated later this year.