rEV131 is smaller than therapeutic antibodies and its compact structure gives good bioavailablity by a number of routes including: injected, inhaled, intraperitoneal, topical (ocular and nasal). The molecule is thermo-stable and can be stored in solution for more than 18 months at room temperature without significant loss of activity. This is an attractive feature for a protein drug candidate.
rEV131 is a novel histamine binding protein that modulates the immediate inflammatory response largely caused by the release of pre-formed histamine from mast cells in the skin. This molecule binds histamine at two active sites, one of which has an affinity for histamine 10 - 100 times higher than any known histamine receptor. This enables rEV131 to out compete the body's natural receptors and prevent histamine from reaching and activating them.
There are at least four different natural histamine receptors. The most recently discovered H4 receptor, was described in 2001, and appears to be involved in the late phase inflammatory process. rEV131 is understood to be the only drug candidate in clinical development, which prevents activation of the H4 receptor.
rEV131 has demonstrated activity against both early and late phase inflammation in clinical and preclinical studies. This differentiates it from approved treatments: anti-histamines used in early phase inflammation and corticosteroid therapies, which are used predominantly in late phase inflammation. A favourable safety profile and a variety of delivery routes provide additional potential advantages for rEV131 over existing therapies.
The H4 subclass of histamine receptors could mediate the histamine signals in peripheral tissues. Displays a significant level of constitutive activity (spontaneous activity in the absence of agonist).