Current Status of Peanut Allergy Treatments

Lack of FDA-Approved Options

Despite the increasing prevalence of peanut allergies among children in North America, there remains no FDA-approved treatment specifically for this condition. The standard recommendation for peanut-allergic individuals is to avoid peanuts entirely and to carry epinephrine for emergency situations, as accidental exposure can lead to severe reactions.

Phase-3 Trial of AR101

Aimmune Therapeutics has developed a new oral treatment for peanut allergies, known as AR101, which recently completed a phase-3 clinical trial. The PALISADE trial, which stands for the Peanut Allergy Oral Immunotherapy Study of AR101 for Desensitization, involved over 550 participants, including more than 490 children aged between four and 17.

Trial Objectives and Results

Evaluation of Efficacy and Safety

The primary aim of the trial was to assess how many participants aged four to 17 could ingest the equivalent of two peanut kernels without experiencing allergy symptoms. The findings were published in the New England Journal of Medicine.

Participant Tolerance Levels

Participants were randomly assigned to receive either AR101 in increasing doses or a placebo over approximately 12 months. Following the treatment phase, those who completed the study underwent a food challenge to evaluate the primary efficacy outcome. The study defined a positive response as the ability to consume 600 mg of peanut proteins without significant allergic reactions.

The results indicated that 67.2% of participants treated with AR101 could tolerate 600 mg of peanut proteins with only mild symptoms, compared to just 4.0% of the placebo group. Additionally, 76.6% of those treated with AR101 tolerated 300 mg, while 50.3% tolerated 1000 mg.

Safety Analysis and Side Effects

Reported Side Effects

A comprehensive safety analysis revealed that both the AR101 and placebo groups experienced high rates of side effects. However, the active drug group reported a higher incidence of gastrointestinal, respiratory, and immunological issues. Serious side effects, classified as such by study investigators, occurred in less than six percent of the active group and less than two percent of the placebo group.

Considerations and Limitations of the Study

Funding and Potential Biases

The study has several limitations, primarily regarding potential biases due to its funding by Aimmune Therapeutics, the company that developed AR101. Several members of the writing committee were employees of the company, which raises concerns about the objectivity of the study’s analysis and conclusions.

Participant Selection Criteria

Additionally, the study’s participant selection may not accurately reflect the general peanut-allergic population. Participants were chosen based on their sensitivity to 100 mg of peanut proteins, excluding those who react to higher doses or have severe asthma or gastrointestinal issues. The maintenance phase of treatment lasted only 24 weeks, making it difficult to ascertain long-term safety and efficacy.

Conclusion

In summary, the phase-3 trial of AR101 demonstrated significant efficacy in peanut-allergic patients aged four to 17, suggesting that the treatment could modify immune responses and increase the tolerance threshold for peanut proteins. However, further research is necessary to include a broader range of participants and to evaluate long-term safety and efficacy for this innovative oral treatment.

References

PALISADE Group of Clinical Investigators. AR101 Oral Immunotherapy for Peanut Allergy. N Engl J Med. 2018.
EurekAlert. Researchers find promise in new treatment for peanut allergy. American Association for the Advancement of Science. 2018 Nov.
Aimmune Therapeutics. 2018 Aimmune Therapeutics.