The U.S. Food and Drug Administration (FDA) has lifted the clinical hold previously placed on a proposed Phase II study of SparVax, a next generation recombinant anthrax vaccine, PharmAthene, Inc. announced.

The clinical hold was enacted in August 2012, prior to the commencement of a proposed Phase II clinical trial of SparVax. In its notification to the Company, the FDA requested that PharmAthene provide additional stability data for both its engineering and GMP lots of U.S. manufactured Final Drug Product, as well as additional information about the intended stability indicating assays. 

SparVax is a next-generation recombinant protective (rPA) anthrax vaccine being developed for pre and post exposure protection against anthrax infection. SparVax has previously been evaluated in three separate Phase I and Phase II clinical trials involving 770 healthy human subjects. These studies suggest that SparVax appears to be well tolerated and immunogenic in humans.

In a letter to the Company, the FDA acknowledged that PharmAthene had satisfactorily addressed all of the Agency's clinical hold issues and that consequently, the clinical hold had been lifted, effective immediately. PharmAthene's rPA anthrax vaccine program has been funded in whole or in part with Federal funds from the National Institute of Allergy and Infectious Disease, National Institutes of Health and the Biomedical Advanced Research and Development Authority.

"We are very pleased by the FDA's thorough review of the SparVax stability data and its subsequent decision to allow our clinical trial to proceed," commented Eric I. Richman , President and Chief Executive Officer. "Anthrax has been identified as one of the foremost potential biological threats to the Nation. The U.S. government's requirement for a recombinant anthrax vaccine for the civilian Strategic National Stockpile is an important national security imperative that remains unfilled. Next-generation anthrax vaccines like SparVax, which employ modern vaccine technology, offer the potential for improved convenience, cost-effectiveness, more rapid immunity, and the ability for large scale rapid delivery. We look forward to working in collaboration with BARDA to fulfill this objective."