Toddlers With Peanut Allergy Tolerate Oral Immunotherapy

LOUISVILLE, Ky. — Kids under 4 years old with peanut allergies seemed to overcome their sensitivity with a treatment using peanut (Arachis hypogaea) allergen powder (PTAH, Palforzia), according to results from the POSEIDON trial.

At the end of the up-dosing schedule, 73.5% of children who were being desensitized using PTAH were able to tolerate at least 600 mg of peanut protein compared with 6.3% of children in the placebo arm of the trial (P<0.0001), reported George Du Toit, MBBch, of King’s College/Guy’s and St. Thomas’ NHS Foundation Trust in London.

In addition, Du Toit said in a presentation at the American College of Allergy, Asthma & Immunology (ACAAI) annual meeting, more children on PTAH were able to tolerate 300 mg, 1,000 mg, and even 2,000 mg doses compared with children on placebo. For example, in the 2,000-mg PTAH group, 61.2% of the children could tolerate that amount of peanut protein while experiencing nothing more than mild symptoms versus 2.1% of the children on placebo (P<0.0001).

PTAH, an oral immunotherapy, is FDA approved to mitigate allergic reactions that may occur with accidental exposure to peanuts. Treatment initiation is indicated for those ages 4 to 17 years with a confirmed diagnosis of peanut allergy. These patients must still avoid peanuts when taking PTAH.

Du Toit noted that POSEIDON is the first study of PTAH in children with peanut allergy who are younger than 4 years. About one-third of the children in the trial had reported a history of an anaphylactic reaction to peanuts, and it had been about 4 months since the children had last experienced a peanut-related reaction.

He said that six children in the PTAH group discontinued participation in the study due to treatment-emergent adverse events (AEs) compared with none of the placebo patients.

“Overall, PTAH demonstrated a favorable safety profile, with no PTAH-related serious or severe adverse events reported. Systemic allergic reactions were similar between the PTAH group and the placebo group — about 8% in each group — and there were no severe or serious systemic allergic reactions,” Du Toit stated.

ACAAI session moderator and meeting program chair Brian Kelly, MD, of Midwest Allergy and Asthma Clinic in Omaha, Nebraska, told MedPage Today, “This is an exciting potential opportunity. If we can identify these children with peanut allergies at a very young age, and you start them on these treatments young, they appear to be able to tolerate a much higher level of peanut than they would even have been able to tolerate in the past.”

“It appears to work better in these young children even compared to similar studies of the agent with older children,” Kelly added, noting the lower rates of AEs.

POSEIDON was a double-blind, placebo-controlled, randomized phase III study that evaluated the efficacy and safety of PTAH in peanut-allergic children, ages 1 year to 3 years, in North America and Europe.

Developer Aimmune Therapeutics said it plans to submit post-publication POSEIDON results to the FDA in the first half of 2023 to support the use of PTAH in peanut-allergic children, ages 1-3 years.