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Study on Hydroxychloroquine for Patients with Cutaneous Mastocytosis or Indolent Systemic Mastocytosis with Skin Involvement

Verified siteRegistered drugNo placebo
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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 the medication hydroxychloroquine on patients with a condition called mastocytosis. Mastocytosis is a disease where certain cells in the body, known as mast cells, grow in excess and can cause symptoms like itching and skin flushing. The study is specifically looking at two types of mastocytosis: isolated cutaneous mastocytosis, which affects the skin, and indolent systemic mastocytosis, which involves the skin and other parts of the body.

The purpose of the study is to evaluate how well hydroxychloroquine can reduce symptoms such as itching and flushing over a period of 12 months. Participants in the study will take hydroxychloroquine in the form of a film-coated tablet, with a daily dose adjusted to their body weight. The study will also involve a comparison with a placebo to assess the effectiveness of the treatment. Additionally, the study will monitor other symptoms related to mast cell activation, such as diarrhea and joint pain, and will evaluate the safety of the treatment.

Another medication, lidocaine, combined with epinephrine, is also mentioned in the study, but it is not the primary focus. The study will last for 12 months, during which the changes in symptoms and the safety of hydroxychloroquine will be closely observed. The goal is to determine if hydroxychloroquine can be an effective treatment for reducing the symptoms of mastocytosis and improving the quality of life for those affected by this condition.

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

    Beginning of the trial

    Upon joining the study, you will be informed about the trial's purpose and procedures. You will be asked to provide consent to participate.

    You will undergo an initial assessment to confirm eligibility, which includes checking your age, medical condition, and other criteria.

  2. Step 2

    Treatment initiation

    You will start taking the medication hydroxychloroquine in the form of a film-coated tablet. The dosage will be between 6 to 6.5 mg per kilogram of your body weight per day.

    The medication is taken orally every day for a duration of 12 months.

  3. Step 3

    Regular monitoring

    Throughout the trial, you will have regular check-ups to monitor your symptoms and any side effects. This includes assessing changes in symptoms like itching and flushing.

    You may be asked to report any other symptoms such as diarrhea, frequent urination, joint pain, or discomfort.

  4. Step 4

    Safety assessments

    The safety of the treatment will be evaluated regularly. This involves checking for any adverse effects of the medication.

    You will be required to use effective contraception during the treatment and for 8 months after stopping the medication if you are of childbearing age.

  5. Step 5

    End of treatment

    At the end of the 12-month treatment period, your symptoms will be evaluated to determine the effect of the medication.

    The study will also assess the change in mast cell mass and other symptoms from the start to the end of the treatment.

Who can join the trial?

7 criteria

  • Age must be over 18 years.
  • Must have either Isolated Cutaneous Mastocytosis or Indolent Systemic Mastocytosis with skin lesions, as defined by the World Health Organization (WHO) or international standards for cutaneous mastocytosis.
  • Must experience at least one of the following symptoms at a moderate to severe level:
    • Cutaneous pruritus (itchy skin) with a score of 3 or higher on a scale from 0 to 10.
    • At least 5 episodes of flushing (sudden redness of the skin) per week.
    • Must have a known Skin KIT mutation (a specific genetic change related to mastocytosis).
    • Must have a performance status of 1 or less on the OMS/ECOG scale (a scale that measures how the disease affects daily living abilities).
    • Women and men of childbearing age must use effective contraception during treatment with hydroxychloroquine and for up to 8 months after stopping it.

Who cannot join the trial?

10 criteria

  • Patients with any other serious health condition that might interfere with the study.
  • Patients who are pregnant or breastfeeding.
  • Patients who have had an allergic reaction to hydroxychloroquine or similar medications in the past.
  • Patients who are currently participating in another clinical trial.
  • Patients with a history of drug or alcohol abuse.
  • Patients who have a condition that affects their ability to understand or follow the study instructions.
  • Patients with severe liver or kidney disease.
  • Patients with certain eye conditions, as hydroxychloroquine can affect the eyes.
  • Patients who have a history of heart rhythm problems.
  • Patients who are taking medications that might interact with hydroxychloroquine.
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Investigated drugs

Hydroxychloroquine is a medication that is being tested in this clinical trial to see if it can help reduce symptoms like itching and flushing in patients with certain types of mastocytosis, which is a condition that affects the skin and sometimes other parts of the body. The trial aims to find out if taking hydroxychloroquine for a year can improve these symptoms in people with this condition.

What is already known about the treatment

Hydroxychloroquine – Hydroxychloroquine is taken orally in the form of tablets. It is currently being studied for its effects on symptoms of mastocytosis, a condition where certain cells in the body grow excessively and cause skin issues like itching and flushing. The medication is thought to work by reducing the activity of these cells, which can help alleviate symptoms. Hydroxychloroquine is classified as an antimalarial and immunomodulatory drug, meaning it can modify the immune system's response.

Investigated diseases

Mastocytosis – Mastocytosis is a condition characterized by an abnormal accumulation of mast cells in the skin and sometimes in other parts of the body. In cutaneous mastocytosis, the skin is primarily affected, leading to symptoms such as itching and flushing. Indolent systemic mastocytosis involves the skin and may also affect other organs, but progresses slowly. Symptoms can include skin lesions, gastrointestinal issues like diarrhea, and discomfort. The disease can cause episodes of mast cell activation, leading to symptoms like pruritus and flushing. Over time, the number of mast cells may increase, potentially leading to more pronounced symptoms.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2024-518594-33-00Protocol codeRC31/19/0504Estimated enrolment30 patientsSponsorCentre Hospitalier Universitaire De Toulouse

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