A new follow-up study highlights the efficacy and safety of the daily oral immunotherapy in. younger patient populations.
An open-label follow-up study evaluating the efficacy and safety of the oral biologic Peanut Allergen Powder-dnfp (PTAH) found improved safety and tolerability profiles in children with peanut allergy.
The daily oral immunotherapy had also been linked to an increased quality of life and continued clinical and immunological responses.
Montserrat Fernandez-Rivas, MD, PhD, and colleagues from Spain, the United Kingdom, and the US noted that the daily administration of PTAH had been established in previous trials such as the PALISADE, ARC004, and ARTEMIS trials, which involved children and adult patients.
However, they believed the long-term benefits warranted further research, especially when younger patient populations were considered.
The most recent study enrolled 142 participants from both the PALISADE and ARC004 trials, all of whom tolerated a 300 mg dose of PTAH with no new safety concerns. Participants aged 4-17 years were eligible.
Including the PALISADE trial, participants were treated for a total of roughly 1.5-2 years with the oral immunotherapy. In the current study, participants were treated with a daily dose of 300 mg of PTAH for 28 (for Group A) or 56 (Group B) weeks.
Efficacy was assessed via a double-blind placebo-controlled food challenge (DBPCFC).
Additional outcome measures like skin prick testing (SPT), peanut-specific antibody assays, and scores on the Food Allergy Quality of Life Questionnaire (FAQLQ) and Food Allergy Independent Measure (FAIM) were used for the study.
The 2 questionnaires were issued during the PALISADE trial prior to the DBPCFC.
Fernandez-Rivas and colleagues included safety assessments that monitored the incidence of adverse events (AEs) such as including allergy symptoms, hypersensitivity reactions, systemic allergic reactions, and anaphylaxis.
With these assessments came efficacy and safety endpoints.
The efficacy endpoints included desensitization to peanut protein, the single highest administered dose, the maximum severity of symptoms at each challenge dose, and the incidence of adrenaline use as a rescue medication during the DBPCFCs.
Safety endpoints included the incidence of treatment-emergent AEs (TEAEs) during the overall study period, incidences of systemic allergic reactions, use of adrenaline as a rescue medication, AEs leading to discontinuation, gastrointestinal (GI) AEs of clinical interest, and accidental food allergen exposure.
Participants in Group A and B who received ≥1 dose of PTAH were considered the safety population and the primary population for all safety analyses. The investigators would collect data from each group and summarize their findings in descriptive statistics that covered the changes from baseline to the end of the study (PALISADE entry to ARC004 exit).
Of the participants who completed the study, 104 (94.5%) came from Group A and 26 (81.3%) from Group B.
The investigators found the percentage of participants able to tolerate higher doses of peanut at the exit DBPCFC rose with longer duration of PTAH treatment.
At ARC004 exit, 80.8% of participants who completed 2 years of treatment (Group B) tolerated the highest challenge dose of 2000 mg without dose-limiting symptoms, versus 48.1% of those who completed ~1.5 years of treatment (Group A).
Additionally, the percentage of participants who required adrenaline as rescue medication during the exit DBPCFCs were 24.0% for those who completed ~1.5 years of treatment (Group A) and 3.8% for those who completed ~2 years of treatment (Group B).
Most participants experienced 1 or more treatment-emergent AEs, but they were not life-threatening and did not result in the death of any participants. The overall exposure-adjusted AE rate decreased in both groups during the intervention period.
An immunological parameter assessment found that mean peanut skin prick tests wheal diameters decreased from the initial screening to the exit of the ARC004 trial, with the most important reductions occurring after the PTAH dosing.
Mean changes in the food allergy quality of life of participants were positive. The self-reported scores in Groups A and B, respectively, were −0.75 (95% CI: −1.21, −0.29) and −0.44 (95% CI: −1.74, 0.85) in children, and −0.64 (95% CI: −1.18, −0.11) and –0.80 (95% CI: –1.72, 0.12) in teenagers.
Food Allergy Independent Measure Child-Form (FAIM) scores were also promising, as children and teenagers recorded significant improvements. Investigators noted the greatest improvements were seen in “likelihood of having a severe reaction” and “chance of dying from accidental exposure” in teenagers and caregivers of teenagers aged 13–17.
Despite some common AEs recorded in the study, Fernandez-Rivas and colleagues believed the continued doses of PTAH resulted in increased tolerance of peanut allergy in the young participants.
They noted how other oral immunotherapy peanut formulations had also been resulted in partipants having improved safety, tolerability, and food allergy quality of life.
Though the careful monitoring of AEs during the trial did not mimic the general awareness of everyday life, the investigators believed the findings presented much needed insight into the long-term safety, tolerability, and efficacy of PTAH.
"The association between extended dosing with PTAH treatment and a trend towards improved FAQoL is intriguing and warrants further investigation,” the team said. “Longer-term data on this cohort will continue to be gathered on participants enrolled in the follow-on ARC008 study.”
The study, “Open-label follow-on study evaluating the efficacy, safety, and quality of life with extended daily oral immunotherapy in children with peanut allergy,” was published online in the European Journal of Allergy and Clinical Immunology.