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How a skin patch could be safe treatment for peanut allergies

March 2, 2015


A skin patch that experts say could be a breakthrough treatment for peanut-allergy sufferers appears to be both safe and effective, according to an early stage clinical trial that involved Seattle-area children, among others, to test the potentially lifesaving technology.

The Viaskin Peanut patch made by the French biotech firm DBV Technologies boosted the amount of peanut protein it took to elicit an allergic reaction by at least 10-fold, particularly in kids younger than 12.

That’s according to the first results of a multicenter, gold-standard clinical trial presented recently at the annual meeting of American Academy of Allergy, Asthma and Immunology in Houston, Texas.

The trial tested whether an immunotherapy patch can effectively desensitize allergy sufferers by administering small amounts of peanut protein into the outer layers of the skin, activating an immune response, but without releasing antigens into the bloodstream, where they trigger allergic shock.

"What they wanted was to find out, on average, if patients could tolerate at least 10-fold as much peanut protein after being on the patch as before being on the patch," said Dr. Stephen Tilles, a physician partner at Northwest Asthma & Allergy Center in Seattle, which oversaw 11 area participants.

It’s a novel treatment that poses fewer challenges — and dangers — than allergy shots or oral immunotherapy, in which sufferers eat small amounts of reaction-producing foods to desensitize their bodies to the triggers, Tilles said.

For 11-year-old Spencer Baty of Issaquah, one of the participants in the peanut-patch trial, the test has been a success. He went from having an allergic reaction to as little as one-tenth of a peanut to having a reaction only when exposed to 10 peanuts — or more.

That could mean the difference between having — or avoiding — a potentially fatal reaction, said Lisa Geschke Sawyer, a spokeswoman for the Seattle Food Allergy Consortium, or SeaFAC, which works to bring allergy-related clinical trials to Seattle.

"Your biggest fear is to get something with a little bit of (an allergen) in it," said Sawyer, whose own son is allergic to cashews and pistachios. "It’s a big deal to have this here now."

The double-blind trial included 221 participants ages 6 to 55 — 113 of them under age 12 and 73 ages 12 to 17 — at sites in the U.S., Canada, France, the Netherlands and Poland. They were tested to see how much peanut protein it took to elicit a reaction, and then asked to wear adhesive patches infused with doses of 50, 100 or 250 micrograms of peanut protein. After a year they were tested again to see if their reaction thresholds were higher.

The 250-microgram patch, the highest dose, was the most effective, according to the study led by Dr. Hugh Sampson, a professor of pediatric allergy and immunity at the Mount Sinai Hospital in New York. In children ages 6 to 11, more than 53 percent responded to the infused patch, versus less than 20 percent who responded to a placebo. Significantly, none of the participants required epinephrine injections to stop allergic reactions, indicating that the patch is safe, Tilles said.

The results are encouraging, said Dr. James Baker, chief executive of Food Allergy Research & Education, or FARE, an advocacy group.

About 15 million people in the U.S. have food allergies, and the rate of peanut allergies among children tripled between 1997 and 2008, according to the Centers for Disease Control and Prevention.

"It is a crucial time to accelerate the development of new therapeutics," Baker said.

The next step is a Phase III clinical trial, the final hurdle before submitting the product for consideration by the federal Food and Drug Administration. If all goes well, the product could be available in 2018, Tilles said.

The recent Phase IIb trial lasted a year, but Spencer’s father, David Baty, 53, said the boy was accepted into a two-year extended program in which he’ll continue applying the peanut patches to his back every day. The family would have participated in the trial simply in the interest of advancing science, but the benefit for Spencer has been remarkable, the Batys said.

"I like having the bit of cushion that I have," Spencer said. "If I eat something, it’s not the end of the world."

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