Each year, 50 to 100 Americans die after eating just one or two peanuts. These people are afflicted with a violent allergic reaction to peanuts, the most common food allergy. But recently, an experimental drug has proven in a large clinical study to protect people who have this allergy. Despite this good news, however, further development of the drug is now in limbo because of a convulted dispute over the rights to it between the developer, Houston-based Tanox (TNOX), and its two much larger partners, Genentech (DNA) and Novartis (NVS).
The drug, dubbed TNX-901, has stirred up a good deal of excitement in the allergy world because it's the first preventive treatment for an allergy suffered by 1.5 million people in the U.S. alone. Last September, the Food & Drug Administration granted TNX-901 so-called fast-track status, guaranteeing it a speedy review once marketing approval is requested -- a designation reserved for promising drugs that target dire unmet medical needs. But no moves have been made to start the final clinical trial needed to gain approval because of the legal dispute.
Meanwhile, the Phase 2 study of TNX-901 that showed its effectiveness is being highlighted at the huge American Academy of Allergy, Asthma & Immunology conference in Denver this week. The study of 82 patients suffering severe peanut allergies will be published in the Mar. 14 issue of the New England Journal of Medicine. Each of the patients was given four injections monthly of either a placebo or the drug. The researchers reported that patients receiving TNX-901 raised the average threshold at which they had an allergic reaction from half a peanut to almost nine peanuts.
LURKING DANGER. Dr. Donald Leung of National Jewish Medical & Research Center in Denver, a co-leader of the research team, says TNX-901 "could help lift a cloud of fear that people with peanut allergies live under every time they eat." Many foods contain trace amounts of peanut oil that can trigger a violent or even fatal reaction when people who have this affliction unknowingly eat them. The drug is not a cure, however, and patients would lose its effects if they stopped receiving the injections.
Leung told a news conference in Denver on Mar. 10 that the researchers were all set to proceed with a much larger Phase 3 trial of the drug in January, but the companies shut down the tests because of their legal dispute. "Right now we're on hold," said Leung. "We are not happy about this."
Tanox specializes in developing antibodies that correct diseases caused by an overactive immune system. Its most advanced product is Xolair, an asthma drug developed in partnership with Genentech and Novartis that has run into significant delays at the FDA, where it's awaiting an approval. Xolair and TNX-901 both target the same immune system pathway, called IgE, which is a key player in allergic reactions.
Tanox, however, wanted to keep TNX-901 to itself. Its partners disagreed, claiming the Xolair agreement covered development of all anti-IgE drugs. In October, an arbitration panel ruled that Tanox didn't have the right to develop TNX-901 independently under the terms of its contract with Novartis. A Tanox spokesperson says Tanox, Genentech, and Novartis are now holding discussions in an attempt to resolve the dispute, but no decision has been made as to how they might proceed. By Catherine Arnst in New York