Specialty pharmaceutical company Emergent BioSolutions has initiated a non-interference Phase II study of BioThrax (anthrax vaccine adsorbed) to treat exposure to anthrax spores.

The randomised study will assess non-interference of BioThrax when administed with antibiotics, and is designed to support a new indication application for the vaccine to treat post-exposure prophylaxis.

BioThrax is currently the only FDA-licensed vaccine indicated for pre-exposure prophylaxis.

Emergent BioSolutions biodefense division EVP and president Adam Havey said the BioThrax post-exposure prophylaxis programme is being advanced by the company to improve the clinical utility of the vaccine.

"Inhalation anthrax is highly lethal when left untreated. Through our partnership with the Biomedical Advanced Research and Development Authority (BARDA), we are exploring how our vaccine can fit in the current PEP treatment regimen, which consists of only oral antibiotics," Havey said.

"We remain committed to working in partnership with BARDA to advance critical countermeasures that help ensure the nation’s preparedness."

Assessment of the vaccine’s impact on ciprofloxacin when the antibiotic is administered before and after a 3-dose series of BioThrax is the primary objective of the non-interference study.

The open-label study, which will enrol a total of 120 healthy adult volunteers, is also designed to provide additional safety data on the simultaneous administration of ciprofloxacin and BioThrax.

Company expects to report preliminary study data in the fourth quarter of 2013.

Image: A photomicrograph of Bacillus anthracis bacteria using Gram-stain technique. Photo: Courtesy of CDC.