Skip to content
Clinical Trials – home

Rare diseases

Investigational molecules

Locations

Our offerNewsroom

Not yet recruiting

Standardization of Cynodon dactylon allergen extract for skin‑prick testing in patients with allergies

InvestigationalNo placebo
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

What is this trial about?

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

The study focuses on people with Allergies and uses a solution containing Cynodon dactylon in a skin-prick test. During the test a tiny drop of the solution is placed on the skin and a very small puncture allows the substance to reach the surface layer; a negative control using sodium chloride and a positive control using histamine dihydrochloride are also applied for comparison.

The purpose is to standardize how strong the allergen extract is by measuring the size of the raised bump (wheal) that forms after the test. Participants will attend a few visits where the different drops are applied, the reaction is recorded, and any side effects are noted. No other medication or treatment is given beyond the test drops.

Safety is monitored throughout the study by observing any adverse reactions that may occur after the skin exposures. Information is collected only to understand the allergen’s activity and to ensure the procedure is safe.

The research process

The trial runs in 6 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial Study Visit

    You arrive at the clinic on the scheduled day and confirm your participation. A study staff member explains the purpose of the visit and obtains your written consent.

    Your medical history related to allergies is reviewed to ensure you meet the study criteria.

  2. Step 2

    Skin Prick Test Procedure

    A small amount of each solution is placed on the surface of your forearm:

    Cynodon dactylon extract (test solution) – 10 mg/ml, applied by a gentle prick into the epidermis (the outer layer of skin).

    Sodium chloride (negative control) – 10 mg/ml, applied by a small puncture under the skin (subcutaneous).

    Histamine dihydrochloride (positive control) – 10 mg/ml, also applied subcutaneously.

    Each solution is applied only once during this visit.

  3. Step 3

    Observation Period

    After the pricks, you remain seated for about 15 minutes while the skin reaction develops.

    The study staff watches for the formation of a wheal (a raised, red bump) at each application site.

  4. Step 4

    Measurement of Reactions

    The diameter of each wheal is measured with a ruler or a calibrated device.

    The area of each wheal (in square millimetres) is recorded for later analysis.

  5. Step 5

    Safety Monitoring

    You are asked about any discomfort, itching, or other symptoms that may have occurred during the test.

    Any adverse reactions are documented, even if they are mild.

  6. Step 6

    Study Completion

    After the observations, the test site is cleaned and you are given instructions to keep the area dry for the rest of the day.

    No further medication or visits are required unless a safety issue arises.

Who can join the trial?

6 criteria

  • The patient can understand what the study is about and has signed the informed consent form, which is a written agreement to take part.
  • The patient is between 18 and 50 years old, and any gender is allowed.
  • The patient lives in an area where the grass Cynodon dactylon (Bermuda grass) is common.
  • The patient has an IgE‑mediated allergy (an allergy caused by a specific type of antibody called IgE) to Cynodon dactylon and meets two test requirements:
    • A positive skin prick test, which means a tiny needle prick on the skin caused a raised bump called a wheal that is at least 3 mm larger than the negative control (a blank test).
    • A positive result on an allergen-specific IgE in vitro diagnostic test (a blood test that looks for allergy‑related antibodies) at class 1 or higher.
    • The patient shows a normal skin reaction to a histamine dihydrochloride solution (a chemical that makes a small bump on the skin) with a wheal of at least 4 mm when used as a positive control (a test to confirm the skin can react).

Who cannot join the trial?

8 criteria

  • You have received allergen‑specific immunotherapy (treatment that uses the same allergy extract or other related allergens) within the past 5 years, which could affect the skin test results.
  • You are taking medicines that can interfere with the skin prick test, such as antihistamines (H1 or H2 blockers) or cromoglycate, and you cannot stop them before the test.
  • You have skin lesions (sores, rashes, or other skin problems) or tattoos on the area where the skin test will be performed, which could make the test results unclear.
  • You have any condition that might change how your skin reacts to the test, including being pregnant or breastfeeding, having dermographism (skin that raises when scratched), atopic dermatitis (eczema) on the test area, urticaria (hives), or any other skin disease on the test site.
  • You are unable to understand why the study is being done.
  • You are unable or unwilling to sign the informed consent form required for participation.
  • You are known to be allergic to any of the inactive ingredients (excipients) in the study medication.
  • You are currently taking beta‑blockers, ACE inhibitors, tricyclic antidepressants, or systemic (non‑inhaled) corticosteroids.
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.

We usually reply within a few days

Trial locations

Where you can join this trial

Countries are shaded by recruitment status. Click a recruiting country to ask about joining there.

Not yet recruiting
Not finding your country?

Not sure what to do next?

Joining a clinical trial can seem overwhelming. We guide you step by step, so you know exactly what to expect and how we support you through the process.

See the full process and FAQ

Investigated drugs

  • Diagnóstico prick Cynodon dactylon

    is a liquid solution that contains an extract from the grass *Cynodon dactylon* (also known as Bermuda grass). In the study it is placed on the skin and a tiny prick is made to see if the person’s immune system reacts. A reaction, such as a small raised bump, would indicate that the person is allergic to this grass. This test helps researchers measure how strong the allergic response is and to standardize the allergen extract.

  • Diagnóstico prick control negative

    is a simple saline (sodium chloride) solution used as a negative control during the skin‑prick test. It is applied to the skin in the same way as the allergen extract but should not cause any reaction. By comparing the response to this control, researchers can be sure that any bumps they see are due to the allergen and not just the skin‑prick procedure itself.

  • Diagnóstico prick control positive

    is a solution containing histamine, a substance that reliably causes a small skin reaction. It is used as a positive control to confirm that the skin‑prick test is working correctly. If the skin shows the expected reaction to this solution, it shows that the person’s skin can react and that the test is being performed properly.

What is already known about the treatment

  • Diagnóstico prick Cynodon dactylon

    This allergen extract is applied by a tiny skin prick (intra‑epidermal) using a solution that contains 10 mg/mL of Cynodon dactylon proteins. It is an experimental diagnostic material and is not an approved medication in regular medical practice. The test helps doctors see if a person is allergic to Bermuda grass by looking for a small skin reaction. The extract works because its proteins can bind to specific IgE antibodies, causing a local immune response; it is classified as an allergen extract for skin‑prick testing.

  • Diagnóstico prick control negative

    The negative control is a sterile sodium chloride (saline) solution given subcutaneously during the skin‑prick test. Saline is a well‑known, widely used substance with no therapeutic effect of its own. It is used to show what a normal, non‑reactive skin response looks like. Because it does not trigger immune cells, it is classified as an isotonic saline solution serving as a diagnostic control.

  • Diagnóstico prick control positive

    The positive control contains histamine dihydrochloride and is applied subcutaneously in the same skin‑prick test. Histamine is an established compound available in pharmacies for allergy testing. It is used to confirm that the test system works by producing a predictable redness and swelling at the test site. Histamine causes blood vessels to widen and nerves to fire, creating a visible reaction; it is classified as a diagnostic histamine agent.

Investigated diseases

Allergy - Allergy is an immune system reaction to normally harmless substances such as pollen, foods, or animal dander. When a person is exposed, the immune system releases chemicals that cause symptoms like itching, sneezing, swelling, or redness. Repeated exposures can lead to larger skin reactions or respiratory symptoms. Over time, sensitivity may increase, causing reactions to lower amounts of the allergen. The condition can affect the skin, eyes, nose, lungs, or digestive tract depending on the trigger.
Trial detailsLast updated 29 Oct 2026
Age18+ yearsPhasePhase IITrial ID2025-522597-37-00Protocol codeAPI-EAC-2026-01Estimated enrolment36 patientsSponsorAsac Pharmaceutical Inmunology S.A.

sourced from the EU Clinical Trials Register and site verification

Want to learn more about this trial or check if you can participate?

Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.