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NEW ORLEANS -- Safety of a dermal patch for helping peanut-allergic children tolerate the ubiquitous legume improved over time in a 3-year, open-label study, a researcher reported here.

Although adverse effects (AEs) from the product were common in the first year, they diminished markedly in subsequent years, said Terri Brown-Whitehorn, MD, of Children's Hospital of Philadelphia, in a video presentation at the American College of Allergy, Asthma, and Immunology annual meeting.

The product, known as "epicutaneous immunotherapy" or EPIT for peanut allergy, contains 250 μg of peanut protein, equivalent to about one-thousandth of a whole peanut. Notably, however, its France-based developer, DBV Technologies, is reformulating the product in response to concerns from the FDA about its adhesiveness. The firm said last month that it's for a new efficacy study.

In the safety study that Brown-Whitehorn reported, most of the events were application-site reactions, she said. The EPIT patch is applied to the patient's back and moved among several sites to minimize irritation at any one spot.

REALISE enrolled 393 children (mean age 7), with an initial 6-month, randomized, placebo-controlled phase. A well-documented history of peanut allergy was required for inclusion, including strongly positive results from skin-prick testing and peanut-specific IgE levels of at least 14 kUA/L. Brown-Whitehorn emphasized that children with histories of severe anaphylaxis could participate in the study, and 14 did. (Food challenge was not required, however.)

At this first phase's completion, all remaining participants (n=392, after one child in the placebo group withdrew) went on open-label treatment with the active patch through year 3.

During the first year, most participants (91%) experienced AEs deemed treatment-related. These were not all mild: 11.5% suffered severe reactions and 60.5% had effects rated as moderate. But rates of moderate and severe effects dropped by half in year 2 (34.5% and 4.9%, respectively), and fell still further in year 3 (23.9% and 0.9%, respectively).

At the same time, though, mild reactions continued to be common, experienced by 73.5% of participants in year 3.

A few cases of anaphylaxis from EPIT occurred as well: a total of 17 in 16 participants. However, none were rated severe, and only three participants discontinued the therapy permanently, including one who did not have an anaphylaxis event.

Also, participants with previous histories of severe anaphylaxis did not appear to be at greater risk than others in the trial, Brown-Whitehorn said.

Overall, the treatment-related AE rates seen in REALISE were somewhat better than those reported in a for peanut allergy. Pooled data from 27 studies showed discontinuation rates of 6.6%, with 7.6% of patients using epinephrine to control reactions.

In REALISE, the discontinuation rate was less than 1% and 2.3% needed epinephrine, Brown-Whitehorn said. On the other hand, some of the trials included in the meta-analysis went back to 2009, when peanut OIT was still in its infancy; discontinuations were less common in the later studies.

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