VX-765 is an orally absorbed prodrug of VRT-043198, a potent and selective inhibitor of caspase-1 and 4. In cultures of peripheral blood mononuclear cells stimulated with bacterial products, VRT-043198 inhibited the release of Interleukin (IL)-1β and IL-18, but had no affect the secretion of other cytokines including IL-α, TNFα, IL-6 and IL-8.