High dose peanut patch shows promise for peanut sensitivity
Patients with peanut sensitivity who wore a 250-µg epicutaneous immunotherapy-based peanut patch had a significant treatment response compared to patients wearing patches with smaller doses or placebo, according to phase 2b trial findings recently published in JAMA.
“Numerous single-center studies [on immunotherapies] have been published; although they have demonstrated induction of varying degrees of desensitization, there is concern about significant risk of severe treatment-associated adverse reactions,” Hugh A. Sampson, MD, department of pediatrics, Icahn School of Medicine at Mount Sinai, New York City, and colleagues wrote. “Moreover, only a minority of treated patients achieve any measure of longer-term tolerance.”
Researchers performed standardized food challenges using PRACTALL criteria on 221 patients with peanut sensitivity before starting therapy and following 12, 24, and 36 months of daily peanut patch application. Patients received incremental peanut protein doses of 1, 3, 10, 30, 100 and 300 mg every half hour, with additional doses of 1,000 and 2,000 mg of peanut protein for challenges at 12, 24, and 36 months. One more dose of 1,600 mg of peanut protein was administered at 24 and 36 months. Food challenges were stopped, and eliciting doses determined only when symptoms were present, according to researchers.
Sampson and colleagues randomly assigned these patients to receive an epicutaneous immunotherapy-based peanut patch containing 50 µg (n = 53), 100 µg (n = 56), or 250 µg (n = 56) of peanut protein or a placebo patch (n = 56) for 12 months. The patches were applied on children’s backs and adolescents’ and adults’ inner upper arms each day. The first patch was administered under a researcher’s supervision; all other patches were self-applied at home daily for 3, 6, and 12 hours per day during the first, second and third weeks, respectively, then for 24 hours each day.
Primary endpoints were percentage of treatment responders — those with an eliciting dose of 10-times increase or more and/or reaching 1,000 mg or more of peanut protein — in each peanut patch group vs. those using a placebo after 1 year. Secondary endpoints included treatment-emergent adverse events and percentage of responders by age group.
Researchers observed a significant absolute difference in response rates at month 12 between the 250-µg patches vs. placebo patches (difference = 25%; 95% CI, 7.7-42.3). No significant difference was seen between the placebo patch vs. the 100-µg patch. The 50-µg patch was not compared to placebo due to statistical testing hierarchical rules. The response rate difference between the 250-µg patch vs. placebo was only significant in the 6- to 11-year-old group (difference = 34.2%; 95% CI, 11.1-57.3).
In addition, no dose-related serious adverse events were observed. The percentage of patients with one or more treatment-emergent adverse events in year 1 was similar, and mostly comprised local skin reactions across all age groups. In addition, the study dropout rate for such events was 0.9% and the overall median study adherence was 97.6% after 1 year.
“To our knowledge, this is the largest trial to use the PRACTALL food challenge guidelines,” researchers wrote. “This phase 2b trial and extension study, which included an older and significantly larger patient population enrolled in more diverse study sites in North America and Europe, further validated the clinical efficacy, serological changes, safety, and compliance reported in the Consortium of Food Allergy Research epicutaneous immunotherapy trial.”
“These findings warrant a phase 3 trial,” Sampson and colleagues concluded. – by Janel Miller
Disclosures: Please see the study for a full list of the authors’ relevant financial disclosures.