Soligenix reports results from long-term stability studies of SGX204 anthrax vaccine

Soligenix, Inc. (OTCBB: SNGX) (Soligenix or the Company), a development stage biopharmaceutical company, announced today results from long-term stability studies of its proprietary DNI (dominant negative inhibitor) anthrax rPA (recombinant protective antigen) subunit protein vaccine, known as SGX204. SGX204 is a hyperimmunogenic derivative of PA and is being developed as a vaccine to protect against anthrax disease either as a pre-exposure prophylactic vaccine or post-exposure vaccine.

Positive stability was demonstrated when DNI rPA was subjected to temperatures as high as 70 degrees Celsius for one month.  In that case, DNI rPA retained native configuration with no evidence of denaturation that typically occurs in water buffers under the same thermal conditions. Redundant methods to determine protein structure each yielded results that indicated that the thermally stressed DNI protein retained completely native conformation after exposure to 70C. The water free DNI protein was formulated with common excipients that allow for preservation of protein structure in the dried state. Long-term stability of DNI rPA was also demonstrated after refrigerated storage for more than 7 years. More importantly, when DNI rPA was combined with a potent adjuvant formulation, animals vaccinated with the combination developed high titer neutralizing antibodies that confer protection against anthrax disease. 

"We are very excited about these extraordinary stability results," stated Robert N. Brey, PhD, Chief Scientific Officer of Soligenix. "We believe that the combination of long-term stability over several years with stability at such elevated temperatures has the potential to confer a distinct advantage over other anthrax vaccine technologies currently in development. Further, SGX204 is highly immunogenic and thereby offers the potential for complete immunization with just one or two doses. As with any biodefense product, our goal is to have SGX204 stockpiled by the US government."