AR101 May Protect Against Accidental Peanut Exposure

In general, study patients were able to tolerate a peanut dose 100 times greater at the end of the study than they were able to at the start of the study.
In general, study patients were able to tolerate a peanut dose 100 times greater at the end of the study than they were able to at the start of the study.

This article is part of MPR's coverage of the ACAAI 2018 meeting, taking place in Seattle, Washington. Our staff will report on medical research related to allergy, asthma, and more conducted by experts in the field. Check back regularly for more news from ACCAI 2018.


SEATTLE — For patients with a peanut allergy, it may be possible to protect themselves against accidental ingestion by growing their peanut tolerance over time, according to researchers at the 2018 Annual Scientific Meeting of the American College of Allergy, Asthma and Immunology held in Seattle, November 15 to 19, 2018.1

"Our hope when we started the study was that by treating patients with the equivalent of one peanut per day, many would tolerate as much as 2 peanuts. We were pleased to find that two-thirds of the people in the study were able to tolerate the equivalent of 2 peanuts per day after 9 to 12 months of treatment, and half the patients tolerated the equivalent of 4 peanuts," stated study coauthor, Stephen Tilles, MD, consulting advisor for Aimmune Therapeutics.

AR101 is a novel peanut-derived, oral biologic drug that provides a target daily maintenance of 300mg of peanut protein. The phase 3 PALISADE study (ClinicalTrials.gov Identifier, NCT02635776) assigned 551 patients (aged 4 to 55 years) with a peanut allergy 3:1 to AR101 or placebo in increasing amounts until the maintenance dose was reached (equivalent to one peanut a day). All patients underwent a double-blind, placebo-controlled oral food challenge (OFC) to test for a severe reaction. The primary efficacy end point was the proportion of patients aged 4 to 17 years who could ingest a challenge dose of 600mg or more without dose-limiting symptoms. 

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A total of 80% of patients successfully reached the maintenance dose. Of patients who were 4 to 17 years of age, 67.2% of patients who received AR101 were able to ingest a dose of 600 mg or more of peanut protein at the exit food challenge, without dose-limiting symptoms vs 4.0% of patients who received placebo (difference, 63.2%; 95% CI, 53.0-73.3; P<.001). 

The severity of symptoms was rated "moderate" in 25% of patients in the active treatment group vs 59% in the placebo group; symptoms were rated "severe" in 5% and 11% of patients, respectively. 

In general, study patients were able to tolerate a peanut dose 100 times greater at the end of the study than they were able to at the start of the study. The researchers further reported there were less severe allergic reactions requiring epinephrine intervention during the OFC. Six percent of patients discontinued the study due to gastrointestinal effects; one-third of patients finished the study while experiencing only mild adverse events. 

Among children and adolescents who were highly allergic to peanut, "treatment with AR101 resulted in higher doses of peanut protein that could be ingested without dose-limiting symptoms and in lower symptom severity during peanut exposure at the exit food challenge than placebo," concluded the authors. 

The full study has been concurrently published in The New England Journal of Medicine.2

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References

1. Tilles SA, Lieberman J. Age-related findings from the Peanut Allergy Oral Immunotherapy Study of AR101 for Desensitization (PALISADE) study. Presented at: the Annual Scientific Meeting of the American College of Allergy, Asthma, and Immunology; November 15-19, 2018; Seattle, WA. Abstract 103.

2. The PALISADE Group of Clinical Investigators. AR101 oral immunotherapy for peanut allergy [published online November 18, 2018]. N Engl J Med. doi:10.1056/NEJMoa1812856