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Study of CLU-RX-PHL injection therapy for patients with moderate to severe grass pollen allergy to find the most effective and safe dose

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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 treating patients with allergic rhinitis and rhinoconjunctivitis caused by grass pollen. These conditions cause symptoms like nasal congestion, runny nose, and eye irritation during grass pollen season. The study will test a medication called CLU-RX-PHL, which contains modified grass pollen extract and is given as an subcutaneous injection under the skin. This type of treatment is known as allergy immunotherapy, which helps reduce allergic reactions to specific substances.

The purpose of this study is to determine which dose level of CLU-RX-PHL works best and is best tolerated by patients. The study will compare three different strengths of CLU-RX-PHL (high, medium, and low dose) against a placebo. The treatment will be given over a period of 50 weeks.

During the study, participants will receive injections of either CLU-RX-PHL or placebo. The effectiveness of the treatment will be measured during the grass pollen season by tracking allergy symptoms and the use of additional allergy medications. Participants will need to keep track of their symptoms using an electronic diary. The study team will monitor participants' health throughout the treatment period to ensure safety.

The research process

The trial runs in 5 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial treatment phase

    You will receive subcutaneous injections (injections under the skin) of either CLU-RX-PHL (in low, medium, or high dose) or a placebo solution

    The placebo solution looks, smells, and feels the same as the treatment but contains no active medication

    Your assigned treatment group will be determined randomly

  2. Step 2

    Symptom monitoring during grass pollen season

    You will need to complete an electronic diary to record your daily symptoms and any additional medications used

    The monitoring will focus on both nasal symptoms (such as sneezing, runny nose) and eye symptoms

    You will rate your symptoms using a simple scoring system

    This monitoring will be particularly important during the peak grass pollen period

  3. Step 3

    Quality of life assessment

    You will complete questionnaires about how your allergies affect your daily life

    You will use a visual scale to rate your overall discomfort from allergy symptoms

    These assessments will be done both before and after treatment to measure any changes

  4. Step 4

    Nasal provocation testing

    You will undergo a nasal provocation test before and after treatment

    This test involves applying grass pollen extract to your nose in increasing amounts

    The test helps measure how your sensitivity to grass pollen changes with treatment

  5. Step 5

    Follow-up evaluations

    Regular check-ups will monitor your response to treatment

    Your lung function will be tested if you have asthma

    Blood tests will be conducted to ensure your safety throughout the study

Who can join the trial?

8 criteria

  • Patient must sign an informed consent form before any study procedures begin
  • Age must be between 18 and 65 years at the time of signing the consent form
  • Must have moderate-to-severe allergic rhinitis/rhinoconjunctivitis (allergic nose and eye symptoms) caused by grass pollen for at least 2 years. Patients can participate if they either: - Have well-controlled mild-to-moderate asthma, or - Have no asthma
  • For patients with asthma: Must have FEV1 (amount of air that can be forcefully exhaled in one second) greater than 80% of normal predicted value
  • Must show allergic reaction to Phleum pratense (timothy grass) pollen through: - Positive skin prick test - Specific blood test showing allergy antibodies - History of significant allergy symptoms during grass pollen season - Positive nasal reaction test to grass pollen
  • Must be able to understand and follow instructions for using an electronic diary
  • Must be willing and able to complete regular electronic diary entries about symptoms and medication use
  • Must have laboratory test results within normal range or considered not medically significant if outside normal range

Who cannot join the trial?

15 criteria

  • History of severe allergic reactions (anaphylaxis) requiring emergency treatment
  • Current or past treatment with immunotherapy for grass pollen allergy within the last 5 years
  • Presence of other significant allergies that could interfere with the study results (such as severe pet or dust allergies)
  • Ongoing asthma that requires regular medication
  • Use of medications that could affect the study results, including:
    • Regular use of oral antihistamines
    • Regular use of nasal corticosteroids
    • Use of oral steroids in the past 3 months
    • Pregnancy or planning to become pregnant during the study period
    • Significant medical conditions that could affect participation, including:
      • Heart disease
      • Liver disease
      • Kidney disease
      • Autoimmune disorders
      • Current participation in other clinical trials or within the past 30 days
      • History of drug or alcohol abuse within the past 2 years
      • Any condition that could compromise the ability to follow study procedures
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Investigated drugs

CLU-RX-PHL is an immunotherapy treatment given as an injection under the skin (subcutaneously) to treat grass pollen allergies. This medication is designed to help reduce allergic reactions by gradually exposing the patient's immune system to grass pollen allergens. The treatment aims to decrease allergy symptoms and reduce the need for other allergy medications during grass pollen season.

What is already known about the treatment

CLU-RX-PHL – A subcutaneous immunotherapy medication being investigated in Phase II-III clinical trials for the treatment of moderate to severe allergic rhinitis and rhinoconjunctivitis caused by grass pollen allergies. The drug is administered through subcutaneous injection using a cluster immunotherapy protocol, which aims to gradually build tolerance to grass pollen allergens in patients who have suffered from these allergic conditions for at least two years. This investigational treatment works by modifying the immune response to grass pollen allergens at the molecular level, potentially offering a therapeutic solution beyond traditional symptom management, with ongoing studies focusing on determining optimal dosing for the best balance between efficacy and safety.

Investigated diseases

  • Allergic Rhinitis

    A condition where the immune system overreacts to allergens like grass pollen, causing inflammation of the nasal passages. The condition causes symptoms in both the nose and eyes, including sneezing, runny nose, nasal congestion, and itchy, watery eyes. The symptoms typically worsen during exposure to specific allergens, such as during grass pollen season. Allergic rhinitis can vary in severity from mild to severe, affecting daily activities and quality of life. When the eyes are also affected (rhinoconjunctivitis), patients experience additional symptoms like red, itchy, and watery eyes.

  • Rhinoconjunctivitis

    A combination of rhinitis and conjunctivitis, affecting both the nasal passages and eyes simultaneously. The condition causes inflammation of the nasal membranes and the conjunctiva of the eyes, resulting in both nasal and ocular symptoms. The symptoms include nasal congestion, runny nose, sneezing, along with red, itchy, and watery eyes. The condition commonly occurs in response to allergens such as grass pollen. The symptoms may fluctuate in intensity depending on allergen exposure levels.

Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IVTrial ID2024-517521-25-00Protocol codeSC-3G2AEstimated enrolment560 patientsSponsorROXALL Medizin GmbH

sourced from the EU Clinical Trials Register and site verification

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