IBT is developing STEBVax, a recombinantly detoxified SEB vaccine, for the prevention of toxic shock syndrome from staphylococcus enterotoxin B (SEB) exposure due to nosocomial, environmental or potential bioterrorist events. IBT licensed STEBVax for development from the US Army Medical Research Institute of Infectious Diseases (USAMRIID).
STEBVax is currently the world’s only advanced-stage SEB vaccine candidate. STEBVax is a recombinant engineered form of SEB containing three point mutations that disrupt the interaction of the toxin with human major histocompatibility complex (MHC) class II receptors and render the protein non-toxic while retaining immunogenicity.
STEBVax has been manufactured under current Good Manufacturing Practice (cGMP). Alhydrogel-adjuvanted STEBVax is intended for intramuscular (IM) injection, achieving immune response within 14 days in a primed adult population. Multi-year stability testing indicates a favorable stability profile. In mice and nonhuman primates, STEBVax shows strong immunogenicity and 100% protection vs. SEB challenge with a good safety profile.
STEBVax’s Phase I safety trial is nearing completion, with the final results expected in Spring 2016. On completion of the trial with satisfactory human safety, STEBVax can proceed to Phase 2 studies to define adult dosing and expand the safety database. The Phase 2 data combined with results of pivotal GLP animal studies could form the basis of a data package to obtain Emergency Use Authorization (EUA) and FDA licensure under the Animal Rule.