Kate Johnson

March 02, 2015

HOUSTON — The daily application of a skin patch (Viaskin, DBV Technologies) that releases peanut protein is effective and safe for peanut immunotherapy, according to the largest clinical trial in peanut allergy desensitization to date.

The epicutaneous immunotherapy could be "the first FDA-approved form of therapy for peanut allergy," said Hugh Sampson, MD, from the Jaffe Food Allergy Institute at the Kravis Children's Hospital at Mount Sinai in New York City.

Dr Sampson presented results from the Viaskin Peanut's Efficacy and Safety (VIPES) study here at the American Academy of Allergy, Asthma & Immunology 2015 during a late-breaking abstract session.

Of the 221 peanut-allergic patients involved in the study, 51% were children, 33% were adolescents, and 16% were adults. All underwent a double-blind placebo-controlled food challenge at baseline to establish the threshold peanut dose at which they reacted.

The patients were randomly assigned to wear a daily patch that delivered a 50 µg, 100 µg, or 250 µg of peanut or placebo.

For children younger than 12 years, the patch was placed on the back by a parent; for older children and adults, it was placed on the inner arm.

The primary end point was the ability to tolerate either 1000 mg of peanut protein or 10 times the baseline threshold at 12 months.

 
In children you see a more robust response, and you also see a nice dose response.
 

"In the young children, 50% initially reacted to 50 mg of peanut protein or less, so we were looking for a fairly significant increase in their tolerance to peanut protein," Dr Sampson explained.

After 12 months, the primary end point was met by more patients using the highest-dose patch than using placebo (50% vs 25%; P = .0108).

Overall, the lower-dose patch was not significantly more effective than placebo. However, in children, the overall response rate was significantly higher with a patch of any dose than with placebo (53.6% vs 19.4%; P = .008).

"In children you see a more robust response, and you also see a nice dose response, in that those who received the higher-dose patch were able to tolerate higher amounts of peanut," Dr Sampson reported.

Serologic markers measured at baseline and at 3, 6, and 12 months were significantly better in the high-dose treatment group. There was an initial increase in peanut-specific immunoglobulin (Ig)E, "as we see in many forms of immunotherapy, but by the end of the year, it had dropped back down to the level of initiation in the study," he added.

IgG4 levels increased in a dose-dependent manner; at 12 months, there was a 19-fold increase in IgG4 levels in children younger than 12 years in the high-dose treatment group.

Safety Results

Epicutaneous immunotherapy might be less effective than oral immunotherapy, but it has other advantages, said Dr Sampson.

"With oral immunotherapy, about 90% of kids experience adverse reactions. For each individual dose, that's a pretty high adverse reaction rate," he told Medscape Medical News.

"Most reactions are pretty mild — itchiness in the mouth and throat, nausea, stomach ache — but about 4% to 5% do require therapy for systemic symptoms. When you talk to people in practice, they don't want to deal with that adverse reaction rate. I know in our studies, we have nurse practitioners who are on duty 24/7 fielding those calls," he explained.

In the VIPES study, the safety profile was "excellent," said Dr Sampson.

"Overall, 6% of subjects dropped out, which is quite low for any immunotherapy trial. Of those dropouts, less than 1% had anything to do with patch placement. Only two subjects dropped out because of flaring atopic dermatitis around the patch site, so the safety record seems to be very good," he explained.

This novel and promising therapy "demonstrates good rates of peanut desensitization," said Katie Allen, MD, from the Murdoch Children's Research Institute in Melbourne, Australia, who was not involved in the study.

"Although children are not cured of their peanut allergy, if they continue to apply the daily patches, a good proportion of them will be able tolerate small amounts of peanut if they accidentally ingest it," she told Medscape Medical News.

"The patch appears to be simple and safe, and will offer hope to patients," said Dr Allen. "However, at this point, it appears that the treatment would need to be indefinite."

Dr Sampson acknowledged that at some point, the duration of therapy will have to be determined, "because when you stop any form of immunotherapy, after a period of time the reactivity comes back."

In the meantime, the VIPES trial has been extended for another year. "My anticipation, based on what we see with other immunotherapies, is that we might very well see even more protection," he said.

The study was funded by DBV Technologies. Dr Sampson reports being an unpaid member of the DBV scientific advisory board; serving on advisory boards for Danone, Novartis, sanofi-aventis, ThermoFisher Scientific, and Food Allergy Research & Education; receiving research grants through Mount Sinai from the National Institute of Allergy and Infectious Diseases the National Institutes of Health; being a scientific advisor and 4% owner of ThermoFisher Scientific; having competing relationships with Allertein Therapeutics; consulting for Regeneron; and chairing the Phadia Allergy Research Forum Scientific Selection Committee. Dr Allen has disclosed no relevant financial relationships.

American Academy of Allergy, Asthma & Immunology (AAAAI) 2015: Abstract L28. February 24, 2015.

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