TNX-901 is a drug being tested at National Jewish Medical and Research Center and other locations across America. It is believed that the drug may prevent allergic reactions to small amounts of peanuts, such as remanant in foods.

The U.S. Food and Drug Administration (FDA) has "fast-tracked" the drug. A drug is given fast-track status if it meets a medical need not currently being met by any medication.

It is made by a Houston-based company called Tanox ; there is a legal dispute against this lab that the drug is based on the same anti-asthma sciences paid for by Genentech and Novartis.

TNX-901 is an anti-IgE antibody. IgE is the compound responsible for allergic reactions and severe asthma attacks. An anti-IgE antibody binds IgE and prevents it from initiating an allergic reaction. In clinical trials, people who were very allergic to peanuts were able to eat up to half a peanut before they started to have symptoms. So it wouldn't cure allergies, but it would prevent reactions from accidental exposure. It is already on the market for asthma, called Xolair (Omalizumab is the generic name, but it's not generic yet). The problem is that Xolair isn't approved for use in food allergies and TNX-901 can't be released because Xolair's manufacturer sued Tanox for patent violation. One could get prescribed Xolair without it getting approved for use in allergies, but most insurance will not cover it without FDA approval, meaning it could cost on the order of $1000 a month for a patient.

Recently, TNX-901 has been shelved by its creator Tanox in exchange for money from Genentech and Novartis, and the three companies plan to focus on researching Xolair for use against peanut allergies instead of TNX-901. Xolair entered Phase II trials for use against peanut allergies in July 2004.