Omalizumab monotherapy for patients with vegetable (plant‑based food) allergy due to LTP and profilin sensitization

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What is this study about?

The study focuses on people who have a food allergy to plant‑based foods such as peach, melon, or other vegetables. In these individuals the immune system reacts to tiny proteins called LTP (lipid transfer protein) and profilin, which can cause symptoms ranging from mild itching to serious reactions. The treatment being tested is a medication called omalizumab, which is given as an injection under the skin and is intended to calm the allergic response.

The purpose of the study is to see whether a 16‑week course of omalizumab can make it possible for participants to eat larger amounts of the foods that previously triggered their allergy and to improve their overall quality of life. Participants will receive the medication at regular visits, and during the study they will be asked to try small portions of the problematic foods under medical supervision to check for any reaction. Information about how they feel and any changes in their ability to tolerate the foods will be recorded throughout the trial.

1 baseline assessment

purpose: establish the starting condition before treatment begins.

activities: complete medical history, undergo allergy testing for plant foods, and fill out a quality‑of‑life questionnaire.

all information is recorded for comparison with later results.

2 first injection of omalizumab

medication: omalizumab 75 mg solution for injection in a pre‑filled syringe.

dose: 75 mg administered as a single injection.

the injection is given at the clinic on the first day of the 16‑week treatment period.

explanation: omalizumab is a drug that blocks a specific antibody that contributes to allergic reactions.

3 ongoing omalizumab treatment

additional injections of omalizumab are given according to the trial schedule for a total duration of 16 weeks.

each injection uses the same 75 mg dose.

the exact interval between injections follows the protocol approved for the study.

4 interim clinic visits

periodic visits to the clinic are scheduled to check safety, record any side effects, and assess response to the medication.

during these visits, the same allergy tests and quality‑of‑life questionnaires may be repeated.

5 final assessment at week 16

after completing 16 weeks of omalizumab, a final evaluation is performed.

primary outcome: measurement of the amount of peach (LTP) and melon (profilin) that can be tolerated without reaction.

secondary outcomes: assessment of tolerance to at least one other food linked to LTP or profilin, and comparison of quality‑of‑life scores before and after treatment.

all results are compared with the baseline assessment to determine the effectiveness of the therapy.

Who Can Join the Study?

You must be a male or female between 14 and 55 years old and you must sign the informed consent (a form that shows you agree to join the study) and agree to let a sample of your blood be stored in a biobank.
You must have a vegetable food allergy caused by being sensitised (your immune system reacts) to LTP (a protein found in many fruits) or to profilin (another fruit protein). This must be confirmed by a clear medical history, a positive skin test (a tiny amount of the allergen is placed on your skin to see if it reacts), and a blood test showing specific IgE antibodies to peach LTP (Pru p 3) and to date‑palm profilin (Pho d 2).
You must have had a positive oral challenge test (you ate the food under medical supervision and showed an allergic reaction) to peach and at least one other food if you are allergic to LTP, or a positive oral challenge test to melon and at least one other food if you are allergic to profilin.
You must be part of the group of people who are allergic to LTP and did not get relief after previous treatment with sublingual immunotherapy using Pru p 3 (a therapy where the allergen is placed under the tongue), which is considered a therapeutic failure.

Who Cannot Join the Study?

Being pregnant or breastfeeding.
Having any immune system disease or taking medicines that modify or block the immune system (immunomodulatory or blocking drugs).
Having a mental health condition that prevents following the study requirements, such as severe depression or psychosis.
Having severe eczema (skin allergy) measured by a scoring system called SCORAD, and a lung function test called FEV1 that shows less than 70% of normal capacity, especially if you have asthma.
Having serious mouth inflammation (swelling, infection, or pain) or having had mouth surgery within the past seven days.
Having received pollen allergy immunotherapy (allergy shots or tablets) at any time in the last two years.
Being unable to keep the required study visit schedule or to eat the test food because of work or other personal difficulties.

Where you can join this trial?

Verified and Recommended Sites

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Verified Sites

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Other Sites

Site Name	City	Country	Status
Hospital Regional Universitario de Málaga	Malaga	Spain

Trial status

Country	Status	Recruitment Start
Spain	Not yet recruiting	02.03.2026

Trial locations

Investigated drugs:

Omalizumab

Omalizumab is a medication given by injection. It works by linking to a protein in the blood called IgE, which is a key player in allergic reactions. By attaching to IgE, it helps stop the chain of events that lead to allergy symptoms. In this trial, patients received omalizumab alone for about 16 weeks to see if it can lower their allergic reactions to vegetables that contain LTP and profilin proteins.

Investigated diseases:

Food allergy

Lipid transfer protein (LTP) allergy – A food allergy caused by the immune system reacting to lipid transfer proteins found in many fruits, vegetables, and nuts. When a person with this allergy eats the offending food, symptoms such as itching, swelling, or stomach upset may appear. Repeated exposure can lead to stronger reactions over time. The allergy often begins in childhood or early adulthood and can spread to include new foods that contain LTPs. Symptoms may vary from mild to more noticeable but do not necessarily indicate a severe condition.
Profilin allergy – A food allergy in which the immune system responds to profilin, a protein present in a wide range of plant-based foods. Eating foods containing profilin can cause oral itching, mouth swelling, or mild skin rash. With continued exposure, the body may respond more quickly, and reactions can become more frequent. The condition commonly starts after repeated eating of raw fruits, vegetables, or pollen exposure. Symptoms usually stay limited to the digestive or oral area without progressing to serious complications.

Trial ID:

2025-524629-42-00

Protocol code:

ID/OMA2025

Trial Phase:

Therapeutic exploratory (Phase II)

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Omalizumab monotherapy for patients with vegetable (plant‑based food) allergy due to LTP and profilin sensitization

What is this study about?

Who Can Join the Study?

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