麻豆传媒

SAN ANTONIO -- Peanut oral immunotherapy (OIT) at maintenance doses 10 times lower than conventional dosing may be an effective strategy for desensitizing peanut-allergic patients, according to findings from an ongoing study.

Researchers from academic centers in Toronto and Montreal are randomizing peanut-allergic children to peanut avoidance, very low-dose OIT at a dosage of 30 mg, or standard peanut OIT involving 300 mg of maintenance dosing.

After a year, none of the children in the avoidance group, 11 of 13 in the very low-dose OIT group, and eight of 10 children in the conventional OIT group could tolerate 443 mg of peanut, reported Julia Upton, MD, of the Hospital for Sick Children (SickKids) in Toronto.

Furthermore, six of the children in both the very low-dose and conventional OIT groups were able to tolerate 1,043 mg or higher.

"Very low-dose OIT -- only 30 mg -- likely provides significant peanut desensitization versus avoidance, and it provides a cumulative tolerant dose that is many times higher than maintenance," Upton said at the annual meeting.

Upton explained that there is no known dosing threshold for effective maintenance peanut OIT, and that very-low dosing, if proven effective, would have advantages over the standard 300-mg maintenance dose, such as potentially making long-term treatment or treating multiple food allergies easier and reducing side effects.

She said that children in the study's avoidance group are undergoing a peanut challenge after a year of avoidance, while the protocol in the very low-dose OIT group involves a starting dose of 0.5 mg of peanut, escalating to a maximum of 30 mg, with a food challenge conducted after 1 year and at 21 months. The conventional OIT group also started with a 0.5-mg dose of peanut, with escalation to 300 mg (about one peanut) being the goal, with the same food challenge schedule.

A total of 17 children and adolescents -- median age of 10 years (IQR 8-13) -- who were highly allergic to peanut at study entry were included in each group. Three in the very low-dose group and six in the conventional OIT group withdrew from the study. On average, study participants could tolerate 44 mg of peanut (IQR 14-144) at the beginning of the trial.

Upton noted that studying lower than conventional maintenance peanut OIT doses may guide treatment management if dose escalation proves problematic, and it may reduce side effects and increase the feasibility for wider OIT use, given less "updosing" and a lower cost.

Sesame Allergies

At the same AAAAI session, Ami Shah, MD, of Icahn School of Medicine at Mount Sinai in New York City, presented data from a study examining outcomes among sesame-allergic pediatric patients undergoing sesame OIT, showing that oral desensitization with crushed sesame seeds and tahini can be a safe and effective way to desensitize such children.

Estimates suggest that 0.34% of people in the U.S. are allergic to sesame, Shah noted, and the allergy is not typically outgrown.

She added that despite the fact that as many as one third of people with sesame allergies have experienced severe allergic reactions, sesame OIT is rare in the U.S.

The retrospective chart review included 86 mostly pediatric patients (median age of 3 years, range of 0-24 years), who underwent sesame OIT at a single center from January 2018 through August 2022.

Starting doses varied, but early dosing typically involved 12 crushed sesame seeds (6 mg of sesame protein) with escalation to 1 teaspoon of tahini (1,000 mg of sesame protein).

After 6 months of daily dosing of 1,000 mg of sesame protein (maintenance phase), a food challenge consisting of 1 tablespoon tahini (3,000 mg sesame protein) was conducted.

A total of 51 patients (59%) achieved maintenance and 26 (30%) were still in the build-up phase at the time of presentation.

Nine of the 86 patients (10.5%) discontinued therapy, and 26 (30%) had treatment-related adverse events, with 92% of reactions occurring during the updosing phase. Specifically, three patients discontinued the treatment due to reactions, one due to uncontrolled asthma, one to difficulty with daily dosing, and four for unknown reasons. One patient was treated with epinephrine due to respiratory distress.

Despite these adverse events, Shah said sesame OIT with crushed sesame seeds and tahini represents a potential strategy for the management of sesame allergy.