GSK-2256294

Epoxyeicosatrienoates (EETs) are endogenous regulators of neuroinflammation and cerebral blood flow. Their metabolism to dihydroxyeicosatrienoates (DHETs) is catalyzed by soluble epoxide hydrolase (sEH). After subarachnoid hemorrhage (SAH), EETs' pathway amplification may be a therapeutic target for the prevention of delayed cerebral ischemia (DCI). We conducted a double-blind, placebo-controlled, phase Ib randomized trial of GSK2256294, a pharmacologic inhibitor of sEH, to evaluate the safety profile and to assess biomarkers of neurovascular inflammation in patients with aneurysmal SAH.

Patients were randomly assigned to receive 10 mg of GSK2256294 or a placebo treatment once daily for 10 days, beginning within 72 hours after aneurysm rupture. The primary study end point was safety. Secondary end points included serum and cerebrospinal fluid (CSF) EETs-to-DHETs ratio, cytokine levels, and serum endothelial injury biomarkers, measured at day 7 and day 10 after SAH. Tertiary end points included neurologic status, disposition, length of stay, incidence of DCI, and mortality; these were assessed at hospital discharge and at 90 days.

Ten patients received GSK2256294 and nine patients received a placebo. There were no adverse events related to the study drug. GSK2256294 administration resulted in a significant increase in the EET/DHET ratio at day 7 and day 10 in serum, but not in the CSF. There was a trend for decreased CSF inflammatory cytokines following GSK2256294 administration, but this did not reach statistical significance.

GSK2256294 administration was safe and well tolerated in critically ill patients with SAH, producing an increase in serum EETs and the EET-to-DHET ratio. Our findings support future studies in a larger population to evaluate the role of sEH inhibition in the prevention of DCI after SAH and other forms of brain injury and inflammatory conditions.

ClinicalTrials.gov: NCT03318783.

The pharmacological inhibition of soluble epoxide hydrolase (sEH) has been suggested as a potential therapy for the treatment of pain and inflammatory diseases through the stabilization of epoxyeicosatrienoic acids, endogenous chemical mediators derived from arachidonic acid that show anti‐inflammatory and analgesic effects.1Although several potent sEH inhibitors (sEHI) have been developed, including clinical candidates AR9281, GSK2256294, and EC5026, so far no sEHI has reached the market.2Recently, a new series of benzohomoadamantane‐based ureas endowed with potent inhibitory activity for the human and murine sEH was reported. However, their very low microsomal stability prevented further development.3Herein, novel series of benzohomoadamantane‐based ureas were synthesized, fully characterized, and evaluated as sEHI. Most of them were endowed with subnanomolar inhibitory potencies at the human and murine enzymes. Further in vitro profiling (solubility, cytotoxicity, metabolic stability, CYP450s, hLOX‐5, hCOX‐2, hERG inhibition, permeability) allowed us to select a candidate for efficacy studies.In summary, these novel results and the previously reported studies using other families of sEHI, strongly suggest that sEH may be a target of clinical interest for the treatment of inflammatory and pain‐related disorders.4References: 1‐Morisseau, C.; Hammock, B. D. Annu.Rev. Pharmacol. Toxicol. 2013, 53, 37–58.2‐Sun, C.‐P.; Zhang, X.‐Y.; Morisseau, C.; Hwang, S. H.; Zhang, Z.‐J.; Hammock, B. D.; Ma, X.‐C. J. Med. Chem.2021, 64, 184–215.3‐Codony, S.; Calvó‐Tusell, C.; Valverde, E.; Osuna, S.; Morisseau, C.; Loza, M. I.; Brea, J.; Pérez, C.; Rodríguez‐Franco, M. I.; Pizarro‐Delgado, J.; Corpas, R.; Griñán‐Ferré, C.; Pallàs, M.; Sanfeliu, C.; Vázquez‐Carrera, M.; Hammock, B. D.; Feixas, F.; Vázquez, S. J. Med. Chem., 2021, 64, 5429–5446.4‐McReynolds, C.; Morisseau, C.; Wagner, K.; Hammock, B. D. Adv. Exp. Med. Biol.2020, 1274, 71–99.