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Study on the Effectiveness of PURETHAL Mites for Adults with Moderate to Severe Allergic Rhinitis or Rhinoconjunctivitis Due to House Dust Mite Allergy

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What is this trial about?

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

This clinical trial is focused on studying the effects of a treatment for people with allergic rhinitis or rhinoconjunctivitis, which are conditions that cause symptoms like sneezing, runny nose, and itchy eyes. These symptoms are triggered by an allergy to house dust mites. Some participants may also have asthma, a condition that affects breathing. The treatment being tested is called PURETHAL Mites 50,000 AUeq/mL, which is a type of subcutaneous immunotherapy. This means it is given as an injection under the skin to help the body build up a tolerance to the allergens from house dust mites.

The purpose of the study is to see how effective this treatment is in reducing the symptoms of allergic rhinitis and rhinoconjunctivitis over a period of one year. Participants will receive either the PURETHAL treatment or a placebo. The study will involve regular visits to the clinic for injections and assessments. Participants will be asked to keep a daily diary of their symptoms and any changes they notice. The study will also monitor the safety of the treatment and any side effects that may occur.

In addition to the main treatment, the study will use various tests to assess the participants' allergic reactions. These include skin-prick tests with substances like dog epithelia, cat epithelia, and mugwort pollen extract, as well as nasal sprays and eye drops containing substances like loratadine and azelastine. These tests help to understand how the body reacts to different allergens and to measure the effectiveness of the treatment. The study aims to provide valuable information on managing allergic conditions caused by house dust mites.

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 visit

    Upon joining the study, you will attend an initial visit where you will receive detailed information about the trial. You will be asked to sign an informed consent form, confirming your understanding and willingness to participate.

    During this visit, a series of tests will be conducted to confirm your eligibility. These tests include a skin-prick test to check for allergies to house dust mites, and a nasal provocation test to assess your reaction to specific allergens.

  2. Step 2

    Baseline assessment

    You will be required to complete a daily electronic diary for two weeks. This diary will record your symptoms and any medication you take. It is important to maintain at least 70% compliance with diary entries to ensure accurate baseline data.

  3. Step 3

    Treatment phase

    The treatment phase involves receiving subcutaneous injections of PURETHAL Mites 50,000 AUeq/mL. These injections are administered under the skin and are designed to help your body build tolerance to house dust mites.

    The dosage is 0.5 mL per injection, and the treatment will continue for approximately one year. The frequency of injections will be determined by the study protocol and communicated to you by the study team.

  4. Step 4

    Monitoring and follow-up

    Throughout the treatment phase, you will have regular follow-up visits to monitor your progress and any side effects. These visits will include assessments of your symptoms and overall health.

    You will continue to complete the electronic diary during specific periods, including one week after the seventh maintenance visit and for eight weeks at the end of the treatment.

  5. Step 5

    Final assessment

    At the end of the treatment period, a final assessment will be conducted. This will include a review of your symptom scores, lung function tests, and any changes in your allergy-related blood markers.

    The study team will evaluate the effectiveness of the treatment based on the data collected throughout the trial.

Who can join the trial?

12 criteria

  • Before starting, you must sign a form called the Informed Consent Form (ICF) to show you agree to participate.
  • You need to have a daily Total Nasal Symptom Score (TNSS) of at least 8 out of 12 points at the beginning, based on entries in an electronic diary over 2 weeks. You should fill out the diary at least 70% of the time.
  • If you are a woman who can have children, you must have a negative pregnancy test at the start.
  • Women who can have children must use two effective methods of birth control and agree to continue using them during the study.
  • You must be between 18 and 65 years old when you sign the consent form.
  • You should have a history of moderate to severe House Dust Mite (HDM) allergic rhinitis (with or without asthma) for at least one year before starting the study.
  • You must be willing and able to fill out daily electronic diaries for 4 weeks during the screening period, 1 week after a specific visit, and for 8 weeks at the end of the treatment.
  • Your Forced Expiratory Volume in 1 second (FEV1), a measure of lung function, should be more than 70% at the start.
  • If you have asthma, it must be controlled throughout the study. This means using only certain medications as needed.
  • You must have a positive Skin Prick Test (SPT) for specific dust mites, which means a reaction of a certain size on your skin when tested.
  • You must have a positive Nasal Provocation Test (NPT) for a specific dust mite extract, which means a certain reaction in your nose when tested.
  • Your blood test must show a specific level of IgE antibodies for certain dust mites, which indicates an allergy.

Who cannot join the trial?

10 criteria

  • Patients with any other significant health conditions that could interfere with the study.
  • Patients who are pregnant or breastfeeding.
  • Patients who have participated in another clinical trial within the last 30 days.
  • Patients with a known allergy to the study medication or its ingredients.
  • Patients who are unable to comply with the study procedures.
  • Patients with a history of severe reactions to allergy shots.
  • Patients who are currently using medications that could interfere with the study results.
  • Patients with uncontrolled asthma, meaning their asthma symptoms are not well-managed.
  • Patients with a history of drug or alcohol abuse.
  • Patients with any condition that, in the opinion of the study doctor, makes them unsuitable for the study.
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Investigated drugs

PURETHAL Mites Mixture is a type of treatment known as subcutaneous immunotherapy. It is designed to help people who have allergies caused by house dust mites. This therapy works by gradually exposing the body to small amounts of the allergen, which in this case is a mixture of proteins from dust mites. Over time, this can help the immune system become less sensitive to the allergen, reducing symptoms like sneezing, runny nose, and itchy eyes. This treatment is given as an injection under the skin and is intended for people with moderate to severe allergic reactions, with or without asthma, due to dust mites.

What is already known about the treatment

PURETHAL Mites Mixture – This medication is administered through subcutaneous injections, meaning it is injected under the skin. It is currently being studied in clinical trials to evaluate its effectiveness in treating moderate to severe allergic rhinitis or rhinoconjunctivitis, with or without asthma, caused by house dust mite allergies. The main therapeutic use of PURETHAL Mites Mixture is to reduce allergy symptoms by gradually desensitizing the immune system to house dust mites. At the molecular level, it works by modifying the immune response to allergens, helping the body become less sensitive over time. It is classified as an allergen immunotherapy, which is a type of treatment designed to target and reduce allergic reactions.

Investigated diseases

Allergic Rhinitis – Allergic rhinitis is an inflammation of the nasal passages caused by an allergic reaction to airborne substances, such as pollen, dust mites, or pet dander. It is characterized by symptoms such as sneezing, nasal congestion, runny nose, and itching of the nose, eyes, or roof of the mouth. The condition can be seasonal, occurring at certain times of the year, or perennial, occurring year-round. Over time, exposure to allergens can lead to persistent symptoms and may affect sleep and daily activities. The inflammation can also extend to the eyes, causing allergic conjunctivitis, which results in red, itchy, and watery eyes. Chronic exposure to allergens may also contribute to the development of asthma or exacerbate existing asthma symptoms.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2023-504942-75-01Protocol codePM/0059Estimated enrolment582 patientsSponsorHAL Allergy B.V.

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