Sublingual Immunotherapy May Provide Peanut Allergy Desensitization in Toddlers

Edwin Kim, MD, MS (UNC)

Sustained unresponsiveness, a pivotal, sought-after benchmark in allergic immunotherapy research, may be achievable with early initiation of peanut sublingual immunotherapy designed to desensitize children with peanut allergy.

In late-breaking data presented during the American Academy of Allergy & Immunology (AAAAI) 2021 Virtual Sessions, a team of North Carolina and Texas investigators reported findings showing a dozen toddlers to have undergone sublingual immunotherapy for a peanut allergy were able to pass a sustained unresponsiveness food challenge after 3 years of care.

The 12 peanut-allergic children were also part of a treatment arm which achieved a median peanut tolerance of 4433 mg.

Led by Edwin Kim, MD, MS, of the University of North Carolina School of Medicine, investigators randomized peanut-allergic children aged 1-4 years old with a positive peanut-specific immunoglobulin E (IgE) and skin prick test (SPT) 1:1 to either 4 mg daily peanut protein sublingual immunotherapy or placebo for a study duration of 36 months.

Patient peanut allergy was confirmed by a food challenge prior to baseline.

The younger patient population was a deliberate choice by the investigators. Though previous research has indicated potential benefit in overall desensitization of peanut allergy when sublingual immunotherapy is initiated at younger ages, no safety nor efficacy data has been described in toddler-aged children.

In fact, AR101 (PALFORZIA), the first oral peanut protein immunotherapy approved by the US Food and Drug Administration (FDA) for desensitizing pediatric peanut allergy, is currently indicated in patients aged 4-17 years old.

Kim and colleagues assessed allergy desensitization by way of double-blind, placebo-controlled food challenge with 4333 mg peanut protein. Sustained unresponsiveness was defined as identical food challenge success after discontinuing sublingual immunotherapy for 3 months.

Patients and their families recorded their dosing compliance and any observed adverse events on home diaries shared with investigators.

At total of 50 participants were randomized at 2 academic centers. Median patient age was 2.2 years old, with the treatment and placebo arms having similar demographics in gender, race, ethnicity, atopic history, peanut SPT, and qualifying food challenge results.

Among the 36 participants (19 treatment; 17 placebo) to complete the desensitization food challenge, cumulative median tolerated dose increased from 143 mg to 4443 mg in the immunotherapy group. Among the placebo group, median tolerated dose increased from 43 mg to 143 mg (P <.0001).

Fourteen immunotherapy participants passed the desensitization double-blind, placebo-controlled food challenge; another 12 passed the sustained unresponsiveness mark. Comparatively, 0 and 2 placebo participants achieved such marks, respectively.

Mean peanut SPT had decreased from 10 mm to 3.25 mm in peanut immunotherapy participants, versus an increase from 11.5 mm to 12 mm with placebo (P <.0001). Cumulatively, 1031 immunotherapy doses were associated with patient-reported symptoms, versus 629 placebo doses.

In highlighting the significance of the outcomes, Kim and colleagues noted the need for continued assessment of such an early initiation of sublingual peanut immunotherapy in such a young population of peanut-allergic patients.

“Significant desensitization was observed with peanut sublingual immunotherapy in peanut-allergic toddlers when compared to placebo with a strong potential for sustained unresponsiveness,” they concluded. “Peanut sublingual immunotherapy may be a promising treatment option for early intervention in peanut allergy.”

The study, “Safety and efficacy of peanut sublingual immunotherapy in toddler-aged peanut-allergic children,” was presented at AAAAI 2021.