SGX204

**SGX204** is a proprietary recombinant subunit vaccine developed by Soligenix for protection against anthrax disease caused by *Bacillus anthracis*. It utilizes a translocation-deficient mutant derivative of recombinant Protective Antigen (rPA) with double mutations (K397D and D425K), known as dominant negative inhibitor (DNI), which prevents endosomal membrane translocation and anthrax toxin function while exhibiting hyperimmunogenicity compared to native rPA. Licensed from Harvard College, SGX204 induces neutralizing antibodies against the anthrax toxin complex and is formulated with ThermoVax™ for thermostability, enabling fewer doses and ambient temperature storage for biodefense stockpiling. Initial preclinical development was supported by a $9.4 million NIAID grant, with plans for intramuscular or intradermal administration at low doses; higher-dose intravenous therapeutic use was discontinued due to adverse events.