A recent study indicates that peanut oral immunotherapy (OIT) can be an effective treatment for adults with peanut allergies. the research, published in Allergy, highlights that OIT can lead to desensitization and improve the quality of life (QOL) for those affected. However, the authors note that further studies are necessary to fully understand the long-term safety and efficacy of this treatment across different patient populations.

Peanut allergies are a widespread concern in the Western hemisphere, affecting approximately 1.5% of the population. It is believed that for 75% to 80% of those affected, the allergy persists throughout their lives.this can substantially impact their mental and psychosocial well-being.

traditionally,managing peanut allergies has involved avoiding peanuts,carrying epinephrine for emergencies,and educating individuals on how to manage allergic reactions. In a significant progress,the FDA approved Peanut (Arachis hypogaea) Allergen Powder-dnfp (Palforzia; Aimmune Therapeutics,Inc) in January 2020 for children aged 4 to 17. this approval was extended to children aged 1 to 3 in July 2024, based on data from the POSEIDON (NCT03211247) phase 3 trial.

Palforzia, the first licensed OIT formula, is designed to reduce the severity of allergic reactions, including anaphylaxis, resulting from accidental peanut exposure. OIT involves gradually increasing doses of peanut protein to induce desensitization and modulate the immune system.

The Phase 2 Grown-Up Peanut Immunotherapy trial investigated the effectiveness and safety of OIT in adults with peanut allergies. The study enrolled 21 adults in the OIT group, with an average age of 24.2 years, beginning treatment before the COVID-19 pandemic in March 2020.

The study found that 67% of participants reached the daily maintenance dose and achieved the primary endpoint.While 29% withdrew from the study,this was not directly attributed to OIT. A control group of 12 recruits, with 9 completing the protocol, showed no significant differences compared to the OIT group.

Among the participants,78% in the primary efficacy population tolerated at least 1.4 g of peanut protein, and 67% in the intention-to-treat population met the primary endpoint.The median highest tolerated dose increased significantly from 30 mg to 3000 mg, a 100-fold increase (P <.0001). Additionally, 56% of the primary efficacy population tolerated a cumulative dose of 4.4 g peanut protein, and 48% in the intention-to-treat population.

One participant required epinephrine in the hospital during a baseline food challenge but later completed the OIT protocol and achieved the primary endpoint.During home dosing, 3 patients self-administered epinephrine on 4 occasions.

adverse events (AEs) typically occurred during dose increases in the hospital. the majority of AEs were classified as grade 1 (95.4%), with all grade 2 AEs (4.3%) occurring during up-dosing. One grade 4 reaction occurred while a participant ran after receiving a 1000 mg maintenance dose.

Skin Prick test Results

“Larger studies will be required to further characterize the safety profile…”

Follow-up skin prick tests showed significant reductions in wheal size among the 15 participants who completed the trial protocol. These reductions were observed with undiluted peanut skin prick test extract (median reduction, 2.5 mm) and with 1:10 (3.5 mm reduction), 1:100 (4 mm reduction), and 1:1000 (3 mm reduction) dilutions (P < .001). The control group showed a small reduction at the 1:10 dilution (1.8 mm reduction; P < .05),but not at other concentrations.

Participants undergoing OIT showed post-treatment increases in peanut- and Arachis hypogaea 2-specific Immunoglobulin G. No changes were observed in specific Immunoglobulin E (IgE), and the control group showed no changes during the same period.

Among the participants, 5 out of 21 were IgE-sensitized to Arachis hypogaea allergen 8 (Ara h 8). Approximately 60% of participants sensitized to Ara h 8 experienced local symptoms during OIT, compared to 67% of non-sensitized participants.

Quality of life Improvements

Quality of life (QOL) scores significantly improved at the time of the exit food challenge (mean difference, -1.7 out of total score of 7; P < .001), and these improvements were sustained after a 3-month follow-up compared to pre-OIT.

Food neophobia scores also showed significant improvements (mean reduction of 1.4 out of total score of 7; P < .001), as did food situations scores (increase of 1.5 out of total score of 5; P < .001). The primary efficacy population demonstrated highly significant results for all three parameters.

The study’s limitations include potential bias due to the Simon’s minimax design and a lack of diversity among participants. Further research is needed to address these limitations and to evaluate the longer-term effects of OIT,including whether desensitization can be maintained without daily peanut consumption.

“Larger studies will be required to further characterize the safety profile and identify the group of adult patients most likely to benefit with the minimum risk of systemic adverse reactions, and also if OIT has the potential to lead to long-term tolerance in this age group,” study authors concluded.