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Standardization of Olea europaea pollen extract for patients with olive pollen allergies

Fast replyInvestigationalNo placebo
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What is this trial about?

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

This study focuses on Allergies, specifically reactions to pollen. The goal is the biological standardization of Olea europaea pollen extract, which is a substance derived from olive tree pollen used to identify sensitivities. During the process, several substances are used for a skin-prick test, a method where small amounts of substances are applied to the skin to see if a reaction occurs. These substances include histamine dihydrochloride, used as a positive control to ensure the skin responds correctly, and sodium chloride, used as a negative control to ensure no reaction occurs from the liquid itself.

The study involves applying these different solutions to the skin to observe the physical response. This response is measured by looking at the wheal, which is a small, raised, itchy bump on the skin that appears during an allergic reaction. By measuring the size of these bumps, the relationship between the amount of pollen extract and the body's reaction can be determined. The process helps to ensure that the pollen extracts used in medical settings are consistent and reliable.

The research process

The trial runs in 2 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Skin prick testing

    A skin prick test is performed to evaluate reactions to different substances. this involves applying small amounts of specific liquids to the skin and creating a tiny prick to see how the skin responds.

    A positive control is administered using histamine dihydrochloride at a concentration of 10 mg/ml via a subcutaneous method, which means the liquid is injected just under the skin, to ensure the skin is capable of reacting.

    A negative control is administered using sodium chloride (salt water) at a concentration of 10 mg/ml via a subcutaneous method to ensure there is no reaction to the liquid itself.

    The test substance, which is olea europaea pollen extract (extract from olive tree pollen), is administered via an intraepidermal method, which means the liquid is placed into the top layer of the skin, at a concentration of 10 mg/ml.

  2. Step 2

    Observation and measurement

    The area of the wheal, which is the raised, swollen part of the skin that appears after the test, is measured in square millimeters (mm2).

    The reaction to the olea europaea pollen extract is compared to the reaction caused by the histamine to determine the strength of the extract.

Who can join the trial?

8 criteria

  • You must live in a place where olive trees (Olea europaea) are commonly found.
  • You must be between 18 and 50 years old, regardless of whether you are male or female.
  • You must have an allergy to olive tree pollen that is triggered by IgE, which is a specific type of antibody (a protein in your immune system that reacts to allergens).
  • Your skin prick test, which is a small test where a tiny amount of the allergen is placed on the skin to see if a reaction occurs, must show a wheal (a raised, itchy bump) that is at least 3 mm larger than the one produced by the negative control (a substance used during the test to ensure there is no false reaction).
  • Your specific IgE blood test, which measures the amount of allergy-related antibodies in your blood, must show a level of class 1 or higher.
  • Your skin must react to a histamine solution, which is a substance used during the test to ensure your skin is capable of having an allergic-like reaction, by creating a bump that is at least 4 mm wide.
  • You must be able to understand why the study is being done and what it involves.
  • You must sign an informed consent form, which is a legal document where you agree to participate after being told all the details of the study.

Who cannot join the trial?

13 criteria

  • You have received allergen immunotherapy, which is a treatment involving small amounts of an allergen to reduce sensitivity, using the specific extract being studied or other similar allergens within the last 5 years.
  • You are using medications that could change the results of a skin prick test, which is a quick test where tiny amounts of allergens are placed on the skin to see if a reaction occurs. This includes antihistamines (medicines used to treat allergy symptoms) or cromolyn sodium (a medicine used to prevent allergy symptoms), if they cannot be stopped before the test.
  • You have lesions, which are areas of damaged or abnormal skin, or tattoos in the area where the skin tests will be done.
  • You are pregnant or breastfeeding.
  • You have dermographism, a condition where skin becomes raised and itchy after being lightly scratched.
  • You have atopic dermatitis, which is a type of chronic itchy skin inflammation (often called eczema), in the area being tested.
  • You have urticaria, which is the medical term for hives or itchy red bumps on the skin.
  • You have any other skin disease in the area where the tests will be performed.
  • You are unable to understand why the study is being conducted.
  • You are unable or unwilling to sign the informed consent, which is a formal document where you agree to participate after being told all the details of the study.
  • You have a hypersensitivity, or an allergic reaction, to any of the excipients, which are the inactive ingredients used to make the medicine.
  • You are taking beta-blockers or angiotensin-converting enzyme (ACE) inhibitors, which are types of medications often used for heart or blood pressure issues.
  • You are taking long-term treatment with tricyclic antidepressants (a type of medicine used for depression) or systemic corticosteroids (strong medicines used to reduce inflammation throughout the entire body, unlike inhaled versions used for breathing).
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Investigated drugs

Olea europaea pollen extract is a substance used in skin testing to check for an allergic reaction to olive tree pollen.

What is already known about the treatment

  • Histamine dihydrochloride

    This substance is used as a positive control in skin prick tests and is applied by injecting a small amount just under the skin. It is a well-known chemical widely used in medical diagnostics to ensure that a patient's skin is capable of reacting to an allergen. As a pharmacological agent, it works by binding to specific receptors on immune cells, which triggers the release of chemicals that cause typical allergy symptoms like redness and swelling.

  • Olea europaea pollen extract

    This extract is administered via a skin prick test where a tiny amount is placed into the top layer of the skin to check for sensitivities. It is commonly used in clinical settings to help identify if a person is allergic to olive tree pollen. At a molecular level, the extract works by interacting with the body's immune system to see if it recognizes the pollen proteins as harmful, which helps in diagnosing seasonal allergies.

  • Sodium chloride

    This is a simple salt solution used as a negative control during skin prick testing and is applied through a small prick in the skin. It is a standard, safe substance used in medical procedures to ensure that a skin reaction is actually caused by an allergen and not just by the physical act of testing. It does not trigger an immune response because it lacks the specific molecules needed to activate the body's allergy defense system.

Investigated diseases

Allergies - Allergies occur when the immune system overreacts to a typically harmless substance, such as pollen. Upon contact with the allergen, the body produces antibodies that trigger an inflammatory response. This reaction can manifest as skin irritation, respiratory issues, or other physical symptoms. The severity and type of response often depend on the specific substance encountered. As exposure continues, the immune system may become increasingly sensitive to the trigger.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IITrial ID2025-523866-26-00Protocol codeAPI-EAO-2025-01Estimated enrolment36 patientsSponsorAsac Pharmaceutical Inmunology S.A.

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