Teva licenses drug that could shut down allergic reactions

Professor Francesca Levi-Schaffer and one of her doctoral students Ido Bachelet, at the Hebrew University, Israel, have developed several drugs based on a new approach to tackle diseases such as asthma, allergy and parasitic infections.

Teva Pharmaceuticals has now decided to snap up two of the most advanced compounds.

One of these drugs is currently being investigated in mice as a potential therapy for allergies and asthma.

Although current drugs treat the symptoms, there are none that can prevent an attack - something that Prof. Levi-Schaffer is hopeful her drug will do.

In 2005, over 250,000 people died from asthma worldwide.

The World Health Organization estimates that this rate will increase by 20 per cent within the next decade if urgent action is not taken.

Asthma is the also most common chronic disease among children.

The research has focussed on mechanisms that regulate the function of mast cells - the "villains" in triggering allergic reactions.

When exposed to allergens, mast cells react violently and release an enormous array of pro-inflammatory substances, of which histamine is a well known example.

This leads to a myriad of symptoms, including stuffy nose, rash, and airway constriction to the lethal shock known from food or venom allergies.

Later on, they attract inflammatory cells that will maintain the response, which often persists as a chronic disease.

Therefore, a drug that prevents mast cells from carrying out this function could prevent allergic reactions and also treat some of the symptoms people suffer from when they have a cold.

A receptor protein on mast cells, called CD300a, can be used to virtually shut down mast cell activity.

Although there is an antibody that binds to this receptor and activates it, CD300a itself is spread throughout the immune system and simply targeting it alone could result in widespread, undesired immunosupression.

To overcome this, the scientists combined a fragment of the CD300a antibody with a fragment another fragment that recognises a marker specific to mast cells.

In this way, the drug only works if it can bind to both at once and therefore only interferes with CD300a if it is found on a mast cell.

According to Prof. Levi-Schaffer, the part of the final drug that targets CD300a on the surface of mast cells was an antibody originally discovered by Alessandro and Lorenzo Moretta, two eminent scientists from the University of Genova, Italy.

In fact, Lorenzo Moretta is one of the top cited scientists in the world.

In tests in mice, the antibody potently eliminated four different types of allergic diseases in mice.

Moreover, when mice suffering from severe chronic asthma received the antibody in nose drops, they completely reverted to normal, healthy mice in less than two months.

The team have also designed a similar drug that only binds to CD300a on another type of cell - eosinophils.

These immune system white blood cells also play a role in asthma and allergy but are also responsible for fighting infection by parasites.

Prof. Levi-Schaffer said that the drugs will initially be researched in asthma and allergy and she hoped that human trials would begin "very soon" .

She also revealed that other indications were possible, in fact any mediated by these two types of cell - although she wouldn't divulge which will be actively perused by herself and Teva.

The company remained silent when contacted by DrugResearcher's about the deal.

For his efforts, Chilean-born Bachelet, a first cousin of the president of Chile, Michelle Bachelet, has been named the winner of one of this year's Barenholz Prizes for Creativity and Originality in Applied Research.

Clearly, the prize-givers were not the only ones impressed by the work, with Teva willing to put its money where its mouth is and invest in the antibody.