The management of food allergies has shifted over the past 5 to 10 years from predominantly food avoidance to now also including oral immunotherapy (OIT) as an active treatment option for selected patients. At the American College of Allergy, Asthma & Immunology (ACAAI) 2024 Annual Scientific Meeting, data from several studies evaluating OIT were presented that focused on assessing the clinical response to OIT and on long-term patient outcomes and quality of life.

Following these presentations, featured expert Brian P. Vickery, MD, was interviewed by Conference Reporter Associate Editor-in-Chief Mona Shah, PharmD. Dr Vickery’s clinical perspectives on these findings are presented here.

The intended outcome of OIT for food allergies is desensitization. To achieve desensitization, patients are repeatedly exposed to small doses of the allergen, and these doses are very slowly increased. However, it is difficult to assess the clinical effectiveness of OIT because those with food allergies continue to avoid their allergens while on OIT and experience symptoms only when they are accidently exposed to the allergen. We are still very much in the early days of trying to predict who is going to do well with OIT. Currently, it is very much a trial-and-error process because we do not yet have a validated scoring system, algorithm, or guideline-recommended companion diagnostic testing to use.

At the ACAAI 2024 Annual Scientific Meeting, Matthew GoodSmith, MD, and Christina Ciaccio, MD, MSc, conducted a retrospective chart review and found that patients with high levels of peanut IgE components (Ara h2 and Ara h6), which are measurable with a widely available blood test, were less likely to complete OIT updosing and achieve maintenance (abstract R257). This adds to the results of previous studies showing that IgE levels to whole or component allergens may be important as a baseline predictor of successfully completing the updosing phase of OIT. To move toward personalized treatment selection, larger studies will be necessary to confirm the results.

Another study presented at the recent ACAAI meeting by H. Henry Li, MD, PhD, et al was a retrospective chart review in patients receiving OIT for severe peanut allergies to assess the utility of several assays, including component testing and basophil activation testing (BAT), in monitoring response to peanut OIT (abstract R052). Although the investigators found that BAT was helpful in measuring OIT responses, unlike component testing, BAT is not available in commercial laboratories and is very finicky due to the need for live basophils to be quickly brought to the laboratory, processed, and stimulated. Even under ideal conditions, some people’s basophils are nonresponsive and cannot be stimulated for the test. As a result, BAT remains primarily a research use–only test at present.

Ghinwa Al Hassanieh, MD, and colleages presented a long-term follow-up study at the ACAAI 2024 Annual Scientific Meeting reporting 5-year outcomes of peanut OIT facilitated by the initial use of adjuvant omalizumab. Since OIT is not a disease-modifying treatment, it has to be continued long-term, and there is no evidence that people can stop OIT and continue to enjoy prolonged benefit, as the desensitization is expected to wear off. Studies like this are interesting and important because there is a paucity of long-term outcomes data. In this trial, 37 patients received omalizumab by itself for several months before starting the OIT process. Once they reached the maintenance dose, they stopped the omalizumab. A total of 28 of the 37 patients who were enrolled in the original trial participated in the long-term follow-up. Of these 28 patients, 13 (46.4%) continued peanut OIT for 5 years, 12 (42.8%) discontinued therapy, and 3 (10.7%) were lost to follow-up. Data on allergic reactions were available for 16 patients; 11 of them (68.8%) experienced allergic reactions to peanut OIT over the long-term follow-up period. This occurred years into treatment, when these patients were theoretically desensitized to the peanut allergen. Nevertheless, there were improvements in patients’ IgE levels and quality-of-life scores, which were more pronounced in those who were able to continue OIT compared with those who stopped OIT. This study, although small, suggests that long-term adherence to OIT may be challenging, with a minority of patients able to continue for 5 years.