HHS Contracts with Pfenex to Develop Anthrax Vaccine

HHS has contracted with San Diego-based Pfenex Pharmaceuticals to develop an anthrax vaccine that is effective after exposure — under an agreement valued at up to $143 million.

The contract, announced last week, will support Phase 1 and Phase 2 clinical studies, nonclinical efficacy studies and manufacturing of Pfenex’s mutant recombinant protective antigen anthrax vaccine Px563L.

Under the contract, Pfenex will receive base period funding of nearly $16 million over 30 months, but milestone-based optional periods could boost Pfenex’s take to $143.5 million over five years, according to Paul Wagner, the company’s chief financial officer.

In nonclinical studies, Px563L was effective after two doses administered 28 days apart. By contrast, BioDefense Operations’ BioThrax — the only anthrax vaccine currently licensed by the FDA — requires three doses administered over the same period.

BioThrax has the disadvantage of being licensed for use only prior to exposure as well, meaning wide-scale use after an exposure would require emergency-use authorization from the agency.

Px563L could also be easier and faster to produce than BioThrax. Studies indicate that Pfenex’s novel recombinant technology could produce millions of doses, and the technology could be easily transferred to the Biomedical Advanced Research and Development Authority’s manufacturing arm where even greater quantities could be produced, HHS says. — Jonathon Shacat