Peanut oral immunotherapy in adolescents: study protocol for a randomized controlled trial

Efficacy and safety of low-dose sesame oral immunotherapy in paediatric patients: a protocol for a single-centre, randomised controlled trial

INTRODUCTION

Sesame allergy, though with low prevalence, can result in severe, potentially life-threatening reactions and poses challenges in allergen avoidance due to hidden sources. In the majority of patients, sesame allergy persists and there is currently no effective long-term treatment available. Therefore, oral immunotherapy (OIT) is a promising alternative approach to managing sesame allergy. In this study protocol, we present a randomised controlled trial evaluating the efficacy and safety of OIT with low-dose sesame protein in paediatric patients. The study's aim is to compare OIT with a 300 mg maintenance dose of sesame protein against controls.

METHODS AND ANALYSIS

39 participants aged 3-17 with IgE-mediated sesame allergy confirmed by oral food challenge will be enrolled into the study. The trial will be conducted at the Paediatric Hospital of the Medical University of Warsaw, Poland. The study comprises two arms-sesame OIT and control. In the sesame OIT group, interventions will be administered once daily for up to 18 months. During the first phase, the dose will be escalated every 2-4 weeks, and in the second phase, the maintenance dose of 300 mg sesame protein will continue for 3 months. Members of the control group will receive standard treatment, which includes an elimination diet and will remain under observation for 1 year. The primary outcome is the proportion of participants tolerating a single dose of 4000 mg of sesame protein during the final oral food challenge in the experimental group versus the control group. Secondary outcomes assess adverse events, changes in immunological parameters and the maximum tolerated doses of sesame protein in each group.

ETHICS AND DISSEMINATION

This study has been approved by the Ethics Committee of the Medical University of Warsaw (approval number: KB/269/2023). Results will be published in peer-reviewed journals and disseminated via presentations at international conferences.

TRIAL REGISTRATION NUMBER

NCT06261554.

Novel Approaches in the Inhibition of IgE-Induced Mast Cell Reactivity in Food Allergy

Allergy is an IgE-dependent type-I hypersensitivity reaction that can lead to life-threatening systemic symptoms such as anaphylaxis. In the pathogenesis of the allergic response, the common upstream event is the binding of allergens to specific IgE, inducing cross-linking of the high-affinity FcεRI on mast cells, triggering cellular degranulation and the release of histamine, proteases, lipids mediators, cytokines and chemokines with inflammatory activity. A number of novel therapeutic options to curb mast cell activation are in the pipeline for the treatment of severe allergies. In addition to anti-IgE therapy and allergen-specific immunotherapy, monoclonal antibodies targeted against several key Th2/alarmin cytokines (i.e. IL-4Rα, IL-33, TSLP), active modification of allergen-specific IgE (i.e. inhibitory compounds, monoclonal antibodies, de-sialylation), engagement of inhibitory receptors on mast cells and allergen-specific adjuvant vaccines, are new promising options to inhibit the uncontrolled release of mast cell mediators upon allergen exposure. In this review, we critically discuss the novel approaches targeting mast cells limiting allergic responses and the immunological mechanisms involved, with special interest on food allergy treatment.

Peanut gastrointestinal delivery oral immunotherapy in adolescents: Results of the build-up phase of a randomized, double-blind, placebo-controlled trial (PITA study)

BACKGROUND

Oral immunotherapy to peanut is effective in desensitizing patients but has significant side effects including anaphylaxis and gastrointestinal symptoms. In most protocols, peanut is administered in a vehicle food.

OBJECTIVE

In an exclusively adolescent population, we tested a new approach using sealed capsules of peanut (gastrointestinal delivery oral immunotherapy or GIDOIT) to bypass the upper gastrointestinal tract. The primary aim was to assess the efficacy of the oral build-up phase of GIDOIT and the secondary aim to analyse its safety.

METHODS

Adolescents with a history of a clinical allergic reaction after peanut ingestion were included in a 2-armed, parallel-design, individually randomized, double-blind, placebo-controlled, multicentre trial after a positive double-blind placebo-controlled oral food challenge (DBPCFC1). A central randomization centre used computer-generated tables to allocate treatments. Peanut (or placebo) capsules were ingested daily over a period of 24 weeks with increments every 2 weeks from 2 to 400 mg of peanut protein (pp). Primary outcome was tolerance of 400 mg of pp at DBPCFC2.

RESULTS

Thirty patients were included between September 2013 and May 2014. At DBPCFC2, unresponsiveness to 400 mg of pp was achieved in 17/21 peanut group patients (2 withdrawn patients) and 1/9 in the placebo group (Intention-to-treat analysis, P < .001, absolute difference = 0.7, 95%IC 0.43 0.96). Oropharyngeal symptoms were equally frequent in both groups. No dysphagia or other signs of eosinophilic oesophagitis occurred. Digestive adverse events (AE) were more frequent in the treated group (P = .02), but mild and without compliance issues. Only one severe advent event led to withdrawal in a patient who ingested twice the investigated treatment. Peanut-specific humoral immune responses were modulated.

CONCLUSION

The GIDOIT protocol demonstrated clinical and immunological efficacy and had an acceptable level of safety with weak oropharyngeal symptoms, no dysphagia, mild digestive events and few severe systemic AE.