Description
Belnacasan (273404-37-8) is a prodrug of VRT-043198, a potent (Ki = 0.8 nM ICE/caspase-1; <0.6nM caspase-4) and selective inhibitor of interleukin-converting enzyme/caspase-1 subfamily caspases.1 VRT-043198 ICE/caspase-1 IC50 = 0.67 μM PBMCs, 1.0 μM whole blood.? It inhibited the release of IL-1b and IL-18 from human monocytes in vitro and their production in vivo in models of inflammation. Belnacasan inhibited the activation and expression of the NLRP3 Inflammasome leading to moderation of depressive-like behaviors induced by chronic mild stress2 and prevention of glial pyroptosis in multiple sclerosis models3. It inhibited pyroptosis in vascular smooth muscle cells during atherogenesis suggesting a possible therapeutic effect in treating atherosclerotic disease.4 Belnacasan reduced acute seizures and drug resistant chronic epileptic activity in mice5 and provided neuroprotection in two rat models of temporal lobe epilepsy6.? It also displays protective effects in models of stroke7and Alzheimer’s disease8.
General Description
The cell-permeable prodrug of the caspase-1/4-selective inhibitor VRT-43198 (
Ki in nM = <0.6/Caspase-4, 0.8/Caspase-1, 100/Caspase-8, 560/Caspase-6, 1,030/Caspase-9, 9,000/Granzyme B, 16,000/Caspase-7, 21,500/Caspase-3; IC
50 >100 μM against Cathepsin B & Trypsin). In addition to inhibiting LPS-induced IL-1β production in primary human PBMC cultures (IC
50 ~1 μM), VX-765 is also effective in preventing HIV infection-induced IL-1β production and pyroptosis of CD4 T cells in human lymphoid aggregate cultures (HLAC; CD4 population = 29.2% in non-infected control cultures, 8.3% vs. 30.2% in infected cultures with or without 5 μM VX-765). VX-765 is orally available in mice (Blood
Cmax = 0.78 μg/mL = 1.53 μM;
Tmax = 1.0 h; AUC
last = 2.06 μg · h/mL; 84 mg/kg, p.o.) and shown to display
in vivo anti-inflammatory efficacy against LPS-induced plasma IL-1β production (ED
max = 100 mg/kg, p.o.), Oxazolone-induced delayed-type hypersensitivity (ED
max = 50 mg/kg, p.o.), collagen-induced arthritis (ED
max = 100 mg/kg, p.o.). When administered via intraperitoneal injection, VX-765 is also demonstrated to suppress the severity of seizure induction (ED
max = 50 mg/kg i.p.) among rats receiving kainic acid via intracerebroventricular injection.
References
Wannamaker et al. (2007)(S)-1-((S)-2-{[1-(4-Amino-3-chlorophenyl)-methanoyl]-amino}-3,3-dimethylbutanoyl)-pyrrolidine-2-carboxylic acid ((2R,3S)-2-ethoxy-5-oxotetrahydrofuran-3-yl)-amide (VX-765), an Orally Available Selective Interleukin (IL)-Converting Enzyme/Caspase-1 Inhibitor, Exhibits Potent Anti-Inflammatory Activities by Inhibiting the Release of IL-1b and IL-18, J. Pharmacol. Exp. Ther.?321 509
Zhang et al. (2015) NLRP3 Inflammasome Mediates Chronic Mild Stress-Induced Depression in Mice via Neuroinflammation, J. Neuropsychopharmacol. 18 pyv006
McKenzie et al. (2018) Caspase-1 inhibition prevents glial inflammasome activation and pyroptosis in models of multiple sclerosis, Proc. Natl. Acad. Sci USA 115 E6065
Li et al. (2020) VX-765 attenuates atherosclerosis in ApoE deficient mice by modulating VSMCs pyroptosis, Exp. Cell Res. 389 111847
Maroso et al. (2011) Interleukin-1b biosynthesis inhibition reduces acute seizures and drug resistant chronic epileptic activity in mice, Neurotherapeutics 8 304
Noe et al. (2013) Pharmacological blockade of IL-1b/IL-1 receptor type 1 axis during epileptogenesis provides neuroprotection in two rat models of temporal lobe epilepsy, Neurobiol. Dis. 59 183
Li et al. (2019) Caspase-1 inhibition mediates neuroprotection in experimental stroke by polarizing M2 microglia/macrophage and suppressing NF-kB activation, Biochem. Biophys. Res. Commun. 513 479
Flores et al. (2018) Caspase-1 inhibition alleviates cognitive impairment in an Alzheimer’s disease mouse model, Nat. Commun. 9 3916
