Eritoran Tetrasodium

BackgroundStudies in cell cultures and rodents suggest that TLR4 is involved in the pathogenesis of insulin resistance, but direct data in humans are limited. We tested the hypothesis that pharmacologic blockade of TLR4 with the competitive inhibitor eritoran would improve insulin resistance in humans.MethodsIn protocol I, 10 lean, healthy individuals received the following 72-hour i.v. infusions in a randomized crossover design: saline (30 mL/h) plus vehicle; Intralipid (30 mL/h) plus vehicle; or Intralipid (30 mL/h) plus eritoran (12 mg i.v. every 12 hours). In protocol II, also a randomized crossover design, 9 nondiabetic individuals with obesity received eritoran or vehicle for 72 hours. The effect of eritoran was assessed with euglycemic hyperinsulinemic clamps.ResultsIn protocol I, lipid infusion significantly decreased peripheral insulin sensitivity (M value) by 14% and increased fasting plasma glucose (FPG) concentrations, fasting plasma insulin (FPI) concentrations, and the homeostatic model assessment of insulin resistance (HOMA-IR) index by 7%, 22%, and 26%, respectively. Eritoran did not prevent lipid-induced alterations of these metabolic parameters. Eritoran also failed to improve any baseline metabolic parameters (M, FPG, FPI, HOMA-IR) in individuals with obesity and insulin resistance (protocol II).ConclusionsAcute TLR4 inhibition with eritoran did not protect against lipid-induced insulin resistance. Short-term eritoran administration also failed to improve obesity-associated insulin resistance. These data do not support a role for TLR4 in insulin resistance. Future studies with a different class of TLR4 inhibitors, longer drug exposure, and/or lipid-enhancing interventions richer in saturated fats may be needed to further clarify the role of TLR4 in metabolic dysfunction in humans.Trial registrationClinicalTrials.gov NCT02321111 and NCT02267317.FundingNIH grants R01DK080157, P30AG044271, P30AG013319, and UL1TR002645.

Eritoran (E5564) is Eisai's in-house discovered and developed investigational Toll-Like Receptor 4 (TLR4) antagonist created with natural product organic synthesis technology. It is a structural analogue of Lipid A, which is an activator of endotoxins of bacteria. It has been previously observed to be safe in 14 clinical studies including a large Phase 3 randomized trial in severe sepsis. In order to evaluate therapeutic efficacy by eritoran, we are participating in the international network REMAP-CAP-COVID (Randomized, Embedded, Multi-factorial, Adaptive Platform-Community Acquired Pneumonia COVID) which aims for novel coronavirus medicine development through drug repurposing, and began an international collaborative clinical trial in October 2020 which is designated for confirmed novel coronavirus patients who are hospitalized and are in a progressing disease state. It is hoped that through suppressing the most upstream TLR4 activity which controls production of multiple cytokines by eritoran, the cytokine storm in patients can be suppressed and pneumonia can thus be prevented from becoming severe. On the other hand, E6011 is the only humanized anti-fractalkine (FKN) monoclonal antibody in the world created by KAN Research Institute. E6011 inhibits the tight binding of CD16-positive monocytes (a cell population that highly expresses the FKN receptor CX3CR1) to vascular endothelial cells, which are important for the local inflammatory response. This is expected to suppress the formation and exacerbation of vasculopathy in COVID-19.