Therapeutic effects of TAK-242, a novel selective Toll-like receptor 4 signal transduction inhibitor, in mouse endotoxin shock model.

Ethyl (6R)-6-[N-(2-chloro-4-fluorophenyl)sulfamoyl]cyclohex-1-ene-1-carboxylate (TAK-242), a novel small molecule that selectively inhibits Toll-like receptor 4-mediated signaling, inhibits various kinds of inflammatory mediators such as nitric oxide (NO), tumor necrosis factor (TNF)-alpha, interleukin (IL)-1, IL-6, IL-10, macrophage inhibitory protein (MIP)-2 and prostaglandin E2 from lipopolysaccharide (LPS)-stimulated macrophages. The effects of TAK-242 were evaluated in a mouse model of endotoxin shock. Intravenous administration of TAK-242 to mice 1 h before LPS challenge dose-dependently inhibited LPS-induced increases in serum levels of TNF-alpha, IL-1beta, IL-6, IL-10, MIP-2, and NO metabolites. TAK-242 protected mice from LPS-induced lethality in a similar dose-dependent manner, and rescued 100% of mice at a dose of 1 mg/kg. Interestingly, TAK-242 worked quickly, and showed beneficial effects even when administered after LPS challenge. Even though increases in serum levels of IL-6 and hypothermia were already evident 2 h after LPS challenge, TAK-242 administration inhibited further increase in IL-6 levels and decrease in body temperature. LPS-induced increases in serum levels of organ dysfunction markers, such as alanine aminotransferase, total bilirubin, and blood urea nitrogen, were also significantly suppressed by post-treatment as well as pre-treatment. Furthermore, administration of 3 mg/kg TAK-242 significantly increased survival of mice, even when given 4 h after LPS challenge. These results suggest that TAK-242 protects mice against LPS-induced lethality by inhibiting production of multiple cytokines and NO. TAK-242 has a quick onset of action and provides significant benefits by post-treatment, suggesting that it may be a promising drug candidate for the treatment of sepsis.

Discovery of novel and potent small-molecule inhibitors of NO and cytokine production as antisepsis agents: synthesis and biological activity of alkyl 6-(N-substituted sulfamoyl)cyclohex-1-ene-1-carboxylate.

To develop a new therapeutic agent for sepsis, screening of the Takeda chemical library was carried out using mouse macrophages stimulated with lipopolysaccharide (LPS) to identify a new class of small-molecule inhibitors of inflammatory mediator production. The lead compound 5a was discovered, from which a series of novel cyclohexene derivatives I bearing a sulfamoyl and ester group were designed, synthesized and tested for their inhibitory activity against nitric oxide (NO) production. Derivatives I were synthesized by the coupling of sulfonyl chlorides and anilines with concomitant double bond migration in the presence of triethylamine, and phenyl ring substitution and modification of the ester and cyclohexene moieties were carried out. Among the compounds synthesized, ethyl (6R)-6-[N-(2-chloro-4-fluorophenyl)sulfamoyl]cyclohex-1-ene-1-carboxylate [(R)-(+)-5n, TAK-242] was found to exhibit the most potent suppressive activity for the production of not only NO but also inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) induced by LPS-stimulated mouse macrophages with IC50 values of 1.8, 1.9 and 1.3 nM, respectively. It shows marked beneficial effects in vivo also. Intravenous administration of (R)-(+)-5n at doses of 0.1 mg/kg or more suppressed the production of NO and various cytokines [TNF-alpha, IL-6 and IL-1beta] in the mouse endotoxin shock model. Furthermore, it protected mice from death dose-dependently and all mice survived at a dose of 3 mg/kg. The minimum effective dose to protect mice from lethality in this model was 0.3 mg/kg, which was consistent with those for inhibitory effects on the production of NO and cytokines. Compound (R)-(+)-5n is currently undergoing clinical trials for the treatment of sepsis.