Sublingual Peanut Immunotherapy Provides Long-Term Pediatric Benefit

Edwin H. Kim, MD, MS

New data from a trial assessing long-term sublingual immunotherapy (SLIT) for peanut allergy show an extended regimen of the investigative treatment provides clinically meaningful allergy desensitization in children.

The positive findings come at a time when a pair of peanut immunotherapies—administered orally (AR101) and epicutaneously (Viaskin Peanut)—are nearing marketing decision, while SLIT therapy options are limited to non-food allergies.

Investigators—led by Edwin H. Kim, MD, MS, of the Division of Rheumatology, Allergy and Immunology at the University of North Carolina School of Medicine—sought to assess extended maintenance SLIT in pediatric peanut allergy patients aged 1-11 years old, from a trio of factors: safety, clinical efficacy, and immunologic changes.

Extended maintenance SLIT at a 2 mg/d peanut protein dose was observed in 48 pediatric patients for up to 5 years. Early therapy discontinuation was allowed for patients who reported with peanut skin test wheals of < 5 mm, and peanut-specific Immunoglobulin E (IgE) levels of < 15 kU/L.

Kim and colleagues assessed desensitization through a double-blind, placebo-controlled food challenge with peanut protein doses up to 5000 mg following SLIT treatment completion. For sustained unresponsiveness results, investigators conducted identical double-blind, placebo-controlled food challenges 2-4 weeks post-peanut exposure.

Of the 48 observed children, 37 (77%) completed 3-5 years of SLIT. Another 32 (67%) were able to consume ≥750 mg during the food challenge, and 12 (25%) passed the 5000-mg food challenge without reporting clinical symptoms. Of the 12, 10 demonstrated sustained unresponsiveness in the challenge following 2-4 weeks.

Just 4.8% of all doses were associated with a side effect, with transient oropharyngeal itching reported most commonly. Just 0.21% of all side effects required antihistamine, and none required epinephrine administration.

Investigators observed significant decreases in peanut skin test wheals, peanut-specific IgE levels, and basophil activation. Peanut-specific IgG₄

Peanut skin test wheals, peanut-specific IgE levels, and basophil activation decreased significantly, and peanut-specific Immunoglobulin G4 (IgG₄) levels increased significantly after peanut SLIT.

The team concluded the extended peanut SLIT dosing provided clinically meaningful desensitization for a majority of allergic children. The therapy also provided a balance of “ease of administration and a favorable safety profile.”

In an interview with MD Magazine® while at the American Academy of Allergy, Asthma & Immunology (AAAAI) 2019 Annual Meeting, Kim highlighted the noted successes of differing peanut immunotherapy modalities in pediatric patients.

Their significant successes in young children—he and UNC colleague Scott Commins, MD, noted&mdash;mean an eventuality of earlier and earlier food allergy diagnosis.

“You know, I think at this stage, the data from all different modalities—oral, epicutaneous, even sublingual&mdash;seemed to suggest not that it can't work in older populations, but seems to have a stronger benefit in younger populations,” Kim said. “And then if you kind of add on top of that another layer of this whole idea of early introduction, we're going to be likely diagnosing people with peanut allergy much, much, much earlier.”

Last month, the US Food and Drug Administration (FDA) received the resubmission of Viaskin Peanut biologics license application (BLA). The BLA is scheduled to be decided upon in 2020.

Next week, the FDA’s Allergenic Products Advisory Committee (APAC) will review the BLA of oral therapy AR101.

The study, "Long-term sublingual immunotherapy for peanut allergy in children: Clinical and immunologic evidence of desensitization," was published online in The Journal of Allergy & Clinical Immunology.