Laird Harrison

March 04, 2014

SAN DIEGO — An experimental skin patch reduces allergic reactions to peanuts in children, a new study suggests.

At the end of the 18-month study, children could eat the equivalent of 1.5 peanuts, on average. That was 10 times more than they could tolerate at the beginning of the study.

However, when the patch with peanut protein was compared with a placebo patch for 6 months, the peanut patch did not work any better, said lead investigator Christophe Dupont, MD, from Necker Enfants Malades Hospital in Paris, France.

"Basically, the study was negative," he told Medscape Medical News.

Dr. Dupont presented results from the phase 2 clinical trial here at the American Academy of Allergy, Asthma & Immunology 2014. His poster presentation attracted a crowd of allergists eager to see results from one of the first trials to treat allergies with a patch.

Multiple trials have shown that taking peanut protein orally can increase tolerance, but oral therapy can also make some patients very sick.

 
Most people are going to walk away from this and say it doesn't work.
 

The peanut patches used in this study didn't cause that problem because each contained only 100 µg of peanut protein, Dr. Dupont explained. "The amount of peanut in the patch is so small that even if a child swallows the patch, there will be no problem."

Patients typically wore the small patches on their backs or arms. They replaced an old patch with a new one every 24 hours.

To measure safety and efficacy, Dr. Dupont and his team evaluated 54 children 5 to 17 years of age who were highly sensitive to peanuts.

All participants had peanut-specific immunoglobulin (Ig)E levels above 5 kU/L or a positive skin prick test with a wheal diameter greater than 8 mm. All reacted to 300 mg of peanut protein or less.

Successful responders could tolerate either at least 1000 mg of peanut protein or at least 10 times the amount they could tolerate before the patch therapy.

At 6 months, there was no difference in the number of responders; both the peanut and placebo groups had 2 responders.

Patients using the peanut patch improved their tolerance more than those using the placebo patch, but the difference was not significant.

However, patients in the peanut group experienced a greater increase in peanut-specific IgE than those in the placebo group, as well as a significant increase in peanut-specific IgG4 (= .023).

After 6 months, patients in the placebo group crossed over to the peanut group. The researchers pooled results from the 2 groups and found a steady increase in the mean dose of peanut protein to which the children reacted.

Table. Pooled Mean Cumulative Reactive Dose

Time Point Dose (mg)
Baseline 24.27
6 months 122.6
12 months 303.3
18 months 357.7

 

At 18 months, two-thirds of children were responders. None of the responders was older than 11 years.

The researchers reported 3 severe adverse reactions "possibly related to study drug": a herpetic gingivostomatitis, a hospitalization related to pilonidal abscess, and an anaphylactic reaction that occurred after a study participant ate a kebab sandwich. There were also 190 "application-site disorders."

Dr. Dupont said he believes the patch itself caused only mild adverse reactions, such as pruritus and eczema.

When the researchers were testing how much peanut the patients could eat before reacting, there were 4 severe adverse reactions — 3 anaphylactic and 1 bronchospasm.

For people looking forward to using patches for their peanut allergy, these results are not encouraging, said David Dreyfus, MD, associate clinical professor of pediatrics at Yale University in New Haven, Connecticut, who was not involved with the study.

"Most people are going to walk away from this and say it doesn't work," Dr. Dreyfus told Medscape Medical News. "It's theoretically the best approach, but at this stage it's not convincing."

Dr. Dupont speculated that the peanut protein patch failed to show superiority because the dose was so small. He said he is working with other researchers on a much larger trial that will compare a 100 µg dose with a 250 µg dose.

This study was funded by DBV Technologies. Dr. Dupont and Dr. Dreyfus have disclosed no relevant financial relationships.

American Academy of Allergy, Asthma & Immunology (AAAAI) 2014. Abstract 357. Presented March 2, 2014.

Comments

3090D553-9492-4563-8681-AD288FA52ACE
Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.
Post as:

processing....