The first drug designed to protect the 1.5 million Americans who are severely allergic to even the smallest trace of peanuts also may aid millions more with other food allergies, researchers said.
The drug, called TNX-901 for now, significantly increased the threshold of sensitivity to peanuts during trials, according to data presented Monday in Denver to the American Academy of Allergy, Asthma and Immunology.
While no cure, the still-experimental drug should let people avoid severe complications if they unknowingly eat one or two peanuts, the typical accidental exposure.
Since the drug is designed to grab immunoglobulin-E, or IgE, a molecule that plays a major part in asthma and allergies, it might also help people with other food allergies, said one of the researchers.
"We may be talking 6 to 8 million Americans who will have relief from this medicine," study co-author Dr. Donald Y.M. Leung, of the National Jewish Medical and Research Center in Denver, told the academy's annual meeting.
Though on the fast track for federal approval, the drug is many years away from market and a critical third round of tests has been stalled by legal infighting among the three companies with rights to it.
For 15-year-old Allison Rush, a study participant with a potentially lethal allergy to peanuts, the drug means she will no longer have to be hypervigilant about avoiding even the tiniest bit of peanut contamination.
Before her first treatment, the equivalent of one-60th of a peanut made her throat start closing up, her skin break out in hives, her face swell, and her blood pressure drop. After four monthly injections of TNX-901, it took the equivalent of six peanuts to bring on such an anaphylactic attack. Other symptoms of the attack include shortness of breath and swelling shut of the throat.
"Basically, we would not be seeing people in the emergency room or the morgue from peanut accidents," said Dr. S. Allan Bock, an allergist from Boulder, Colo., who was not part of the study.
Dr. Hugh A. Sampson of Mount Sinai Medical School in New York, also not connected with the study, said patients would need lifelong monthly shots of the drug and still would have to guard against eating peanuts.
Peanut allergies account for 50 to 100 deaths in the United States each year. Some youngsters must eat at peanut-free cafeteria tables or even in an isolated room. Some airlines have stopped serving peanuts.
Peanut allergies have been rising in recent decades. No one is sure why, but a new study found that baby creams or lotions containing peanut oil applied on children may lead to peanut allergies in adulthood.
The TNX-901 study — and research on the effectiveness of the allergy drug — will be published Thursday in the New England Journal of Medicine, which released the results Monday on its Web site.
The study was paid for by one of the drug's developers, Tanox Inc., and by grants from the Peanut Board, the Peanut Foundation and the National Institutes of Health.
In the study, 84 people with immediate allergic reactions to peanuts got monthly shots of either a placebo or TNX-901 for four months. There were three different doses of TNX-901; neither doctors nor patients knew who got what.
Those on the highest dose could handle an average of almost nine peanuts' worth of peanut flour at the end, compared with about a half-peanut at the start. And five of them ate the equivalent of 24 peanuts without reacting.
"That's a pretty impressive amount," Sampson said.
The drug is likely to be expensive even if it hits the market, but none of the companies involved — Tanox, Genentech, and Novartis Pharmaceuticals — would say what it may cost.
Jacqui Corba, 13, wasn't in the first two rounds of tests but has gladly been scheduled for the third set. She once was rushed to the emergency room for a reaction apparently set off when another student opened a bag of peanuts two tables away from her peanut-free table in the cafeteria.
"I would love to be relaxed for once," she said.
On the Net: Food Allergy Network: www.foodallergy.org
American Peanut Council: www.peanutsusa.com