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Efficacy and safety of Depigoid Olea 1000 DPP/ml compared with placebo in patients with moderate to severe allergic rhinoconjunctivitis due to olive pollen

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What is this trial about?

A plain-language summary of the goals, design and what participants do

The trial focuses on people who suffer from allergic rhinoconjunctivitis caused by olive pollen, a condition that produces a runny or blocked nose, sneezing, itchy eyes and sometimes watery eyes. Some participants may also have mild to moderate asthma, a lung disease that makes breathing harder, especially during allergy season. The investigational medication being tested is called Depigoid Olea, a specially processed extract of olive pollen that is given as a subcutaneous injection (an injection under the skin). A matching placebo will be used for comparison. The purpose of the study is to determine whether the medication can reduce allergy symptoms and the need for other medicines during the peak olive pollen season.

Participants will receive a series of injections over several months, with at least eight doses given before the main allergy season begins. Throughout the study, symptoms and medication use will be recorded daily in a simple mobile app, creating a combined score that reflects how severe the symptoms are and how much rescue medication is required. The study will continue through multiple pollen seasons to see if the benefits are maintained, while safety will be monitored by collecting any side‑effects or adverse reactions reported by the participants.

The research process

The trial runs in 7 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Baseline Visit and Initial Allergy Tests

    You will attend a first clinic visit after joining the study. During this visit a conjunctival provocation test is performed by placing five drops of a special olive pollen solution into each eye to see how your eyes react. The test helps confirm that the olive pollen causes your symptoms.

    A prick test is also done on your forearm. A single drop of sodium chloride solution is placed on the skin and a tiny needle gently pricks through the drop. This checks the skin’s response and serves as a control for the allergy testing.

    All results from these tests are recorded before any treatment is given.

  2. Step 2

    Randomization and First Injection

    After the baseline tests you will be randomly assigned to receive either the active medication, Depigoid Olea, or a matching placebo. Randomization means you will not know which one you receive, and the study staff will also be blinded.

    The first dose is given as a subcutaneous injection (injection under the skin) of 0.5 ml. If you are in the active group the injection contains the olive pollen extract; if you are in the placebo group it contains an inactive solution that looks the same.

  3. Step 3

    Repeated Injections (At Least Eight Doses)

    You will receive additional injections of the same volume (0.5 ml) according to the study schedule. The schedule requires a minimum of eight injections, typically spaced several weeks apart, so the treatment period lasts several months.

    Each injection is administered in the same way – a subcutaneous injection in the upper arm – and you will be observed for a short time after each dose to monitor any immediate reactions.

  4. Step 4

    Daily Symptom and Medication Recording

    During the olive pollen season you will use a mobile app to record your daily symptoms and any allergy medication you take. The app calculates a combined symptom‑medication score (cSMS) ranging from 0 (no symptoms) to 6 (severe symptoms).

    You will enter information such as nasal discharge, sneezing, itching, congestion, eye itching and tearing, as well as whether you used antihistamine eye drops, oral antihistamines or nasal steroids.

  5. Step 5

    Seasonal Allergy Threshold Assessment

    After each pollen season (up to three seasons) you will undergo another conjunctival provocation test to measure any change in the concentration of olive pollen needed to produce a positive eye reaction. This helps determine whether the treatment has increased your tolerance to the allergen.

  6. Step 6

    Quality‑of‑Life Questionnaires

    At the start of the study and after each pollen season you will complete standardized questionnaires about how your allergy affects daily life. These include the Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) and its versions for children and adolescents.

    The questionnaires are filled out on paper or electronically and are used to compare how you feel before and after treatment.

  7. Step 7

    Final Evaluation After Third Pollen Season

    After the third olive pollen season you will have a final clinic visit. The visit includes a repeat of the baseline allergy tests, a review of all symptom scores recorded in the app, and collection of blood samples to measure specific antibodies (IgE, IgG4) against olive pollen.

    All data from the injections, symptom recordings, test results and questionnaires are compiled to assess the overall safety and effectiveness of the treatment compared with placebo.

Who can join the trial?

8 criteria

  • Age: You must be at least 5 years old.
  • Allergic rhinitis: You need to have moderate to severe hay‑fever symptoms caused by olive pollen for at least the last two pollen seasons. This may be with or without mild to moderate asthma.
  • Olive pollen sensitivity proof: Your allergy must be confirmed by at least one of these tests: a skin prick test showing a reaction of 3 mm or larger (a tiny needle prick on the skin that shows a small bump if you are allergic), a blood test measuring specific IgE antibodies higher than 0.7 kU/L for olive pollen or the component Ole e1 (IgE is a protein that signals an allergic reaction), or a positive controlled pollen exposure test (CPT) where a small amount of olive pollen is placed on the skin to see if a reaction occurs.
  • Asthma control (if you have asthma): Your asthma must be well‑controlled according to the GINA guidelines (a set of rules doctors use to manage asthma) and your lung function measured as FEV1 must be more than 70% of the normal value (FEV1 is the amount of air you can force out of your lungs in one second).
  • Informed consent: You (or your parent/guardian) must read and sign a consent form showing that you understand the study. If you are a minor, you also need to give an assent form (a simpler agreement for children).
  • Mobile phone and internet: You need a smartphone that works with the study’s cSMS app and an internet connection so you can record your symptoms on the app.
  • Ability to follow the study plan: You must be able to attend required visits, take the study medication as instructed, and answer the app questions correctly.
  • Stay in your home area: You should remain where you live for most of the olive pollen season so the study can track your symptoms accurately.

Who cannot join the trial?

21 criteria

  • Had allergy shots (AIT) within the last five years.
  • Have any reason why a doctor would say they should not receive subcutaneous specific allergen immunotherapy (injection under the skin of allergy medicine).
  • Took oral corticosteroids (steroid pills) in the past 12 weeks, except for short courses (10 days or less) that ended at least four weeks ago.
  • Experienced a severe reaction during skin prick testing (a small needle prick to check allergy).
  • Are medically unstable now (for example, an asthma flare, a respiratory infection, low‑grade fever, acute hives, etc.).
  • Have chronic urticaria (persistent hives), severe dermographism (skin reacts strongly to pressure), severe atopic dermatitis (eczema), sunburn, active psoriasis on the skin‑test area, hereditary angioedema (dangerous swelling), or any condition that makes giving adrenaline unsafe (such as severe heart disease).
  • Are taking immunosuppressive treatment (medicines that lower immune activity) except topical creams.
  • Have another serious disease unrelated to their nose/eye allergy or asthma that could interfere with treatment or follow‑up (for example, epilepsy, movement disorders, birth defects, multiple surgeries, kidney disease).
  • Have uncontrolled autoimmune diseases (like thyroiditis or lupus), active malignancies (cancer), or a diagnosed immunodeficiency (weak immune system).
  • Cannot cooperate with study staff because of severe psychiatric (mental health) disorders.
  • Are allergic to any ingredient in the vaccine other than the olive pollen extract.
  • Show strong sensitisation (positive allergy test) to other seasonal allergens such as grass pollen, Parietaria pollen, or plane tree pollen above specific test levels.
  • Have lower‑respiratory diseases other than asthma, such as emphysema or bronchiectasis.
  • Are a first‑degree relative (parent, sibling, or child) of the study investigator.
  • Are sensitised to the mold Alternaria alternata with a specific IgE level higher than 0.7 kU/L.
  • Are sensitised to house dust mites in a clinically relevant way.
  • Are sensitised to animal skin proteins and live with or regularly contact the animal.
  • Have used biological therapies for T2‑related diseases (type‑2 immune conditions) within the past six months.
  • Have uncontrolled asthma according to the GINA guidelines, asthma attacks in the past three months, or lung function (FEV1) less than 70 % of normal.
  • Are pregnant, planning to become pregnant, or may become pregnant during the study period.
  • Are nursing (lactation).
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Investigated drugs

  • Conjunctival Provocation Test Olea europaea

    is a liquid that is placed as drops on the surface of the eye to see how a person reacts to olive pollen. It contains a small amount of olive pollen extract and helps confirm that the study participants are truly allergic to olive pollen before they receive any treatment.

  • Depigoid Olea

    is an allergy vaccine that is injected under the skin. It is made from a specially treated olive pollen extract that has been depigmented and polymerized, which means it is less likely to cause strong side‑effects while still teaching the immune system to become less sensitive to the pollen. This injection is the active treatment being studied to see if it can lower the symptoms of allergic rhinoconjunctivitis and asthma caused by olive pollen.

  • Prick Test Negative Control

    is a simple skin test that uses a salty (sodium chloride) solution applied with a tiny needle prick. It acts as a control to show that any skin reaction seen during allergy testing is caused by the allergen itself and not by the testing procedure.

What is already known about the treatment

  • Depigoid Olea 1000 DPP/ml

    This medication is a sterile suspension that is given by subcutaneous injection, usually in the upper arm. It is an approved allergen immunotherapy product in several European countries and is well documented in allergy research literature. It is used to treat moderate to severe allergic rhinoconjunctivitis, with or without mild asthma, caused by olive pollen. The depigmented polymerized olive pollen proteins slowly train the immune system to become less reactive, classifying it as a modified allergen extract for immunotherapy.

  • Conjunctival Provocation Test Olea europaea LETI 30 HEP/ml

    This product is a liquid solution applied as eye drops (conjunctival use) to provoke a controlled allergic reaction for testing purposes. It is primarily used in clinical studies and allergy clinics as a diagnostic tool and is not a therapeutic drug. It helps identify sensitivity to olive pollen by temporarily exposing the eye surface to the pollen extract, causing a measurable reaction. The mechanism involves direct activation of eye surface immune cells, placing it in the category of diagnostic allergen extracts.

Investigated diseases

  • Allergic rhinoconjunctivitis

    It is an allergic inflammation of the nose and eyes triggered by inhaled allergens such as pollen. Symptoms include sneezing, runny or blocked nose, itching and watering of the eyes. The condition typically worsens during the pollen season when exposure increases, and may improve during low‑pollen periods. Repeated exposure can lead to more persistent nasal congestion and eye irritation. It is caused by an IgE‑mediated response that releases histamine and other inflammatory mediators.

  • Seasonal allergic asthma

    This is a type of asthma that is triggered by seasonal allergens, most commonly pollen. It is characterized by wheezing, shortness of breath, chest tightness and coughing that become more frequent when allergen levels rise. During the peak pollen season, airway inflammation and hyper‑responsiveness increase, leading to greater symptom severity. Symptoms often lessen outside the allergen season but may persist at a lower level. The underlying mechanism involves IgE‑driven airway inflammation similar to that seen in allergic rhinitis.

Trial detailsLast updated 6 Nov 2026
Age18+ yearsPhasePhase IIITrial ID2026-525840-13-00Protocol code0618-PG-PSC-219Estimated enrolment45 patientsSponsorLETI Pharma S.L.U.

sourced from the EU Clinical Trials Register and site verification

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