Efficacy of 16‑Week Omalizumab Monotherapy in Patients with Plant-derived Food Allergy Mediated by LTP and Profilin Sensitization

Primary objective: To evaluate the clinical efficacy of omalizumab administered as monotherapy for 16 weeks in patients with vegetable allergy driven by lipid transfer protein (LTP) and profilin sensitisation. This assessment determines whether anti‑IgE therapy can meaningfully reduce allergic reactivity to plant‑derived foods.

Secondary objectives:

• To assess changes in food tolerance as reflected by skin test reactivity and controlled oral food challenge with at least two previously reactive foods, comparing pre‑ and post‑treatment responses.
• To characterize immunological alterations post‑treatment, including humoral measurements of specific IgE and IgG4 antibodies to peach LTP (Pru p 3) and palm profilin (Pho d 2), and cellular evaluation of basophil activation to these allergens by flow cytometry.

The trial enrolled male and female participants aged 14–55 years who provided informed consent and agreed to biobank sample storage. All subjects had a documented vegetable allergy attributable to sensitisation to LTP or profilin, confirmed by clinical history, positive skin tests, and specific IgE to the relevant allergens. Inclusion required a positive oral challenge test to peach (or melon) and at least one additional food, and, for the LTP subgroup, documented failure of prior sublingual immunotherapy with Pru p 3. The study population was considered vulnerable and comprised patients rather than healthy volunteers. No additional lifestyle criteria such as diet or physical activity were specified. The sponsor did not provide information on the total number of participants.

The phase 4, open‑label study evaluates the clinical efficacy of monotherapy with omalizumab administered as a 75 mg solution for injection over a 16‑week treatment period in patients aged 14–55 years who have proven vegetable allergy due to sensitisation to lipid‑transfer proteins or profilin. After obtaining informed consent, eligible participants attend a screening visit for medical history, skin testing, specific IgE assessment and a positive oral challenge test to the relevant foods. Baseline assessments and the first dose are given at the enrollment visit (week 0). Subsequent study visits occur at weeks 4, 8, 12 and 16 to administer the drug, monitor safety, and perform quantitative oral food challenges to assess changes in tolerated amounts of peach (LTP) or melon (profilin) and additional related foods. The final visit at week 16 also includes quality‑of‑life questionnaires and collection of biobank samples. Participant involvement therefore spans approximately 18 weeks, encompassing the screening period, 16 weeks of treatment, and the end‑of‑study assessment.

The investigational product is Omlyclo 75 mg solution for injection supplied in a pre‑filled syringe. Each syringe contains 75 mg of omalizumab in a sterile aqueous solution (percentage volume/volume as indicated by the manufacturer) intended for subcutaneous administration. The dose is delivered as a single injection per administration; the treatment period spans 16 weeks, with dosing intervals defined by the study protocol and recorded in the dosing schedule. The pharmaceutical form is a solution for injection, and the route of administration is injection using the pre‑filled syringe device.

No additional active comparator, standard‑of‑care therapy, or placebo is administered; the trial evaluates omalizumab as monotherapy. Participant compliance is assessed by recording each injection in the study log, verification of syringe disposal, and periodic review of dosing records by study staff. Adherence to the dosing schedule is monitored through scheduled clinic visits and electronic case report forms, ensuring that each dose is administered according to the protocol‑specified timing.

Efficacy will be evaluated by measuring changes in food tolerance after 16 weeks of treatment with omalizumab. The primary efficacy parameter is the increase in the amount of peach tolerated by patients sensitized to lipid transfer protein (LTP) and the amount of melon tolerated by patients sensitized to profilin, assessed during a standardized oral food challenge (PPO). Secondary efficacy parameters include quantitative increases in the tolerated amounts of at least one additional food associated with LTP sensitization, quantitative increases in the tolerated amounts of at least one additional food associated with profilin sensitization, and changes in patient‑reported quality of life before and after treatment.

Assessments will be performed at baseline and at the end of the 16‑week treatment period. Food challenge results will be recorded in milliliters or grams as appropriate, and quality of life will be captured using a patient‑reported outcome instrument. Comparative analyses will examine the differences between baseline and week 16 values for each endpoint.