Introduction
Peanut allergy persists for life in the majority of
patients1,2. Current management relies on strict
allergen avoidance; however, up to 50% of peanut allergic patients have
accidental exposures within 1 year3. Moreover,
allergic reactions to peanut can be severe, and account for 30% of food
anaphylaxis deaths4. There is an unmet need for a
treatment that induces long-lasting remission of peanut allergy and
improves health-related quality of life (HRQL).
In clinical trials, patient-reported outcomes, such as HRQL, are vital
to understand the patient perspective and experience since they capture
perceived benefits of treatment not captured by other endpoints.
Regulatory agencies increasingly require these data as part of their
evaluation process5. In drug trials, HRQL is generally
only assessed at baseline and at treatment completion; yet assessment of
HRQL beyond the treatment phase is needed to ascertain whether benefits
are sustained over a longer time period6.
Peanut OIT is effective at inducing desensitization and can induce
sustained unresponsiveness (SU) in a subset of treated patients, however
there is a paucity of data on long-term
effectiveness7,8 and impact on HRQL. Few studies have
evaluated for long-term SU following peanut OIT; these suggest that
OIT-induced SU may be short-lived, with up to 67% of treatment
responders losing their SU status within 12-months7,8.
A meta-analysis of peanut OIT studies found that peanut OIT was
associated with frequent adverse events and did not lead to significant
improvement in HRQL9. Further research to identify
novel approaches that improve the efficacy and safety of OIT are needed.
A combined probiotic and peanut oral immunotherapy (PPOIT) treatment was
shown to induce desensitization (83.9%) and 2-6 week SU (74.2%) after
18-months of treatment in a Phase 2a randomized control trial (PPOIT-001
study; ACTRN 12608000594325)10. Long-term follow-up of
patients showed that PPOIT-induced SU persisted to 4-years
post-treatment in 70% of initial treatment
responders11. PPOIT treatment also resulted in
improved HRQL compared with placebo, with improvement specifically
related to the attainment of SU12. Weaknesses of the
Phase 2a study included the selection of subjects with peanut allergy
based upon a clinical history of reaction and positive peanut skin prick
test (SPT) or specific-IgE (sIgE) rather than double-blind
placebo-controlled food challenge (DBPCFC) and assessment of SU at 2-6
weeks post-treatment rather than a longer period after treatment.
This study aimed to confirm previous findings using a more stringent
8-week post-treatment SU test in children aged 1-12 years with
challenge-confirmed peanut allergy. Safety, HRQL and long-term outcomes
were also evaluated.