Butyrylcholinesterase (BuChE) is a naturally occurring protein found in minute quantities in human blood (2 mg/liter). BuChE functions as a natural bioscavenger, like a sponge, to absorb and degrade poisons (e.g. nerve agents) before they cause neurological damage.

Approaches to utilising cross species sources or recombinant technologies (including bacterially expressed and expression in goats milk) to generate sufficient quantities for use in an emergency have met with a multitude of problems including immunological issues and lower functional efficacy.

Stabilitech is developing a novel recombinant form of human BuChE which is being developed as a pre- and post-exposure therapy following exposure to susceptible agents.

Stabilitech is in the unique position of being able to deliver reproducible doses of infectious non replicating viral vectors to the luminal surface of the intestinal mucosa. Once the epithelial lining cells are infected they can produce proteins which can accumulate in the blood. The proteins can be expressed for several days but if necessary further doses of vector can be administered to extend the period over which the cells express the protein of interest.

rBuChE MECHANISM OF ACTION

The mechanism of action of rBuChE is reversal of the acute toxicity associated with OP agents used in chemical warfare (cholinergic crisis) by removing them directly from the bloodstream by breaking them down into inactive components, rather than just treating the symptoms, as is the case with existing therapies.

Multiple efficacy studies using a broad spectrum of live nerve agents have demonstrated that rBuChE is a potent bioscavenger of nerve agents and can act as both a prophylactic as well as a post-exposure therapeutic.

THE MARKET

Both the U.S. Department of Defense (DoD) and the civilian Health and Human services (HHS) have requirements for a broad spectrum pre and post exposure prophylaxis for nerve agent exposure. The current DoD requirement is for full force protection so the stockpile would need to be sufficient to protect all of the branches of the military as well as civilian first-responders.