Oral, on-the-skin immunotherapies show promise against peanut allergy in children

Children who are allergic to peanuts may benefit from two immunotherapies, one oral and another epicutaneous or on-the-skin, which have demonstrated safety and efficacy in separate studies presented at the recent AAAAI 2023.

In the first study, EPITOPE, use of the 250-μg peanut patch (VP250) resulted in greater response from peanut-allergic children aged 1‒3 years as compared to placebo, regardless of whether the patients were allergic to other foods or just peanuts at study entry.

“The safety and tolerability profiles were similar in peanut-allergic children randomized to VP250 with peanut allergy alone or peanut with concomitant food allergies (CFA),” said the researchers led by Dr David Fleischer of the Children's Hospital Colorado, University of Colorado, Aurora, Colorado, US.

Of the participants, 242 (66.9 percent) had CFA and 120 (33.1 percent) were solely peanut-allergic at baseline. Among those with CFA, the responder rate was 64.1 percent with VP250 relative to 34.7 percent with placebo (risk difference [RD], 29.4 percent, 95 percent confidence interval [CI], 15.97‒42.80). [J Allergy Clin Immunol 2023;doi:10.1016/j.jaci.2022.12.088]

In children with isolated peanut allergy, the responder rate was 72.7 percent with VP250 as compared with 31.4 percent with placebo (RD, 41.3 percent, 95 percent CI, 21.42‒61.22).

Serious treatment-emergent adverse events (TEAEs) associated with VP250 occurred in one (1.2 percent) participant with solely peanut allergy and none in those with CFA. In addition, two (2.4 percent) children with isolated peanut allergy and six (3.7 percent) with CFA discontinued participation in the study due to these TEAEs.

EPITOPE was a phase III, randomized, double-blind, placebo-controlled trial of VP250 in 362 children 1‒3 years of age. Fleischer and his team defined the primary outcome based on eliciting dose at month 12 double-blind placebo-controlled food challenge and analysed the missing primary endpoint data using multiple imputation. They assessed safety and efficacy outcomes in children with and without CFA.

POSEIDON trial

In the second study, POSEIDON, peanut-allergic children 1‒3 years of age who received oral immunotherapy with peanut (Arachis hypogaea) allergen powder-dnfp (PTAH) showed a favourable and acceptable profile. Systemic allergic reaction (SAR) rates between PTAH and placebo were similar, and only a few discontinued treatment. [J Allergy Clin Immunol 2023;doi:10.1016/j.jaci.2022.12.097]

Of the 146 children analysed, 98 received PTAH and four placebo. Most adverse events (AEs) reported were mild or moderate. Severe AEs occurred in 5.1 percent of children in the PTAH arm relative to 4.2 percent of those in the placebo arm. None, however, were related to treatment in either group.

The most common treatment-related AEs were cutaneous (49 percent vs 37 percent), gastrointestinal (47 percent vs 21 percent), and respiratory (36 percent vs 25 percent). The frequency of SARs and treatment-related SARs was 8.2 percent and 2 percent, respectively, for PTAH, while the corresponding frequency for placebo was 8.3 percent and 0 percent. Severe SARs were not reported.

In addition, treatment-related epinephrine use was reported in two PTAH participants, with a total of three events. No events were noted for placebo. Discontinuation rates due to AEs were 5.1 percent and 2.1 percent for PTAH vs placebo, respectively.

POSEIDON is an international, double-blind, placebo-controlled, randomized phase III efficacy and safety trial with PTAH in children aged 1‒3 years. The study was led by Dr George Du Toit of Guy's and St Thomas' NHS Foundation Trust in London, UK.

Du Toit and colleagues randomized children 2:1 to PTAH or placebo. Participants continued maintenance with 300 mg/day for ∼12 months of overall treatment following initial dose escalation and up-dosing. The researchers assessed AEs, including SARs, severe AEs, and epinephrine use.