Molecule

Description

Epilepsy

Description

VX-765 is a potent and selective inhibitor of caspase-1 with K_i of 0.8 nM.

Targets

IC₅₀

In Vitro

VX-765 is an orally absorbed prodrug of VRT-043198, which exhibits potent inhibition against ICE/caspase-1 and caspase-4 with Ki of 0.8 nM and less than 0.6 nM, respectively. And VRT-043198 also inhibits IL-1β release from both PBMCs and whole blood with IC50 of 0.67 μM and 1.9 μM, respectively. ^[1]

In Vivo

In collagen-induced arthritis mouse model, VX-765 (200 mg/kg) inhibits LPS-induced IL-1β production by about 60%, and results in a dose-dependent, statistically significant reduction in the inflammation scores and effective protection from joint changes. ^[1] In vivo, VX-765 blocks kindling epileptogenesis in rats by preventing IL-1β increase in forebrain astrocytes without significant effect on afterdischarge duration. ^[2] In the mouse model of acute seizures, VX-765 (50 mg/kg-200 mg/kg) produces the anticonvulsant effect by delaying the time to onset of the first seizure and decreasing the number of seizures as well as their total duration by average 50% and 64%. ^[3] In adult rats with genetic absence epilepsy (GAERS), VX-765, after the 3rd drug injection, significantly reduces the cumulative duration and number of spike-and-wave discharges (SWDs) by 55% on average by selectively blocking IL-1β biosynthesis. ^[4]

Clinical Trials

VX-765 is currently in Phase II clinical trials in patients with treatment-resistant partial epilepsy.

Features

VX-765 is a potent and selective inhibitor of interleukin-converting enzyme/caspase-1.

Protease Enzyme Assays

Enzyme inhibition is assayed by tracking of the rate of hydrolysis of an appropriate substrate labeled with either p-nitroaniline or aminomethyl coumarin (AMC) as follows: ICE/caspase-1, suc-YVAD-p-nitroanilide; caspase-4, Ac-WEHD-AMC; caspase-6, Ac-VEID-AMC; caspase-3, -7, -8, and -9, Ac-DEVD-AMC; and granzyme B, Ac-IEPD-AMC. Enzymes and substrates are incubated in a reaction buffer [10 mM Tris, pH 7.5, 0.1% (w/v) CHAPS, 1 mM dithiothreitol, and 5% (v/v) dimethyl sulfoxide] for 10 minutes at 37 °C. Glycerol is added to the buffer at 8% (v/v) for caspase-3, -6, and -9 and granzyme B to improve stability of enzymes. The rate of substrate hydrolysis is monitored using a fluorometer.

Animal Models

Collagen-induced arthritis mouse model.

Formulation

VX-765 is dissolved in 25% Cremophor EL.

Doses

≤200 mg/kg

Administration

Administered via p.o.