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Study on the Effectiveness and Safety of Masitinib for Patients with Severe Systemic Mastocytosis Unresponsive to Treatment

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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 a condition known as Systemic Mastocytosis, which is a rare disorder where there is an excess of mast cells in the body. Mast cells are a type of white blood cell that play a role in allergic reactions and other immune responses. The study specifically targets two forms of this condition: Smouldering Systemic Mastocytosis and Indolent Systemic Mastocytosis. These forms are characterized by severe symptoms that do not respond well to standard treatments. The trial aims to evaluate the effectiveness and safety of a medication called masitinib, which is a type of drug known as a tyrosine kinase inhibitor. This medication is taken orally in the form of coated tablets.

The purpose of the study is to compare the effects of masitinib with a placebo in patients who have not found relief from their symptoms with other treatments. The trial will last for 24 weeks, with a possibility of extension. Participants will be randomly assigned to receive either masitinib or a placebo, and neither the participants nor the researchers will know who is receiving which treatment. This is known as a double-blind study. The trial will involve regular visits to monitor the participants' health and response to the treatment.

Throughout the study, the main focus will be on assessing how well the treatment works in reducing the symptoms and improving the quality of life for those with systemic mastocytosis. The trial will also look at various biological and skin parameters to gather more information about the condition and the effects of the treatment. The ultimate goal is to find a more effective way to manage the symptoms of this challenging condition.

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

    Randomization

    Upon joining the study, participants are randomly assigned to one of two groups. This process is called randomization and ensures that each participant has an equal chance of receiving either the masitinib treatment or a placebo.

    The study is double-blind, meaning neither the participants nor the researchers know who is receiving the actual treatment or the placebo.

  2. Step 2

    Treatment administration

    Participants receive either masitinib or a placebo in the form of a coated tablet taken orally.

    The dosage of masitinib is either 100 mg or 200 mg, depending on the group assignment.

    The tablets are taken daily for a period of 24 weeks.

  3. Step 3

    Monitoring and assessments

    Throughout the 24-week period, participants attend regular study visits for monitoring and assessments.

    These visits include evaluations of the participant's response to the treatment, focusing on the improvement of symptoms related to mastocytosis.

    Participants are assessed for any side effects or adverse reactions to the treatment.

  4. Step 4

    Primary analysis

    The primary analysis focuses on the response to treatment regarding three specific handicaps associated with mastocytosis.

    This analysis is conducted from week 8 to week 24 to determine the effectiveness of the treatment.

  5. Step 5

    Secondary analysis

    Secondary analyses include evaluations of biological and skin parameters, as well as the participant's quality of life.

    These assessments help provide a comprehensive understanding of the treatment's impact beyond the primary endpoints.

  6. Step 6

    Possible extension

    After the initial 24-week period, there may be an option for participants to continue in an extension phase of the study.

    The decision to extend participation is based on the participant's response to the treatment and overall health status.

Who can join the trial?

12 criteria

  • Patient must have a documented type of mastocytosis, either Smouldering Systemic Mastocytosis (SSM) or Indolent Systemic Mastocytosis (ISM).
  • Patient must be able and willing to attend study visits and follow study procedures.
  • Patient must be able to understand, sign, and date the written informed consent form before any study-specific procedures.
  • Patient must be able to understand and follow instructions on a patient card, especially if they experience severe neutropenia (a low level of white blood cells) or severe skin reactions.
  • Patient must have an excess of mast cells (a type of immune cell) or abnormal mast cells in at least two organs, such as the skin, bone marrow, or digestive tract.
  • Patient must meet specific criteria for systemic mastocytosis, which may include abnormal findings in a bone marrow sample or specific genetic mutations.
  • Patient must have severe symptoms of mastocytosis over a 14-day period, such as intense itching, frequent flushing, or a high score on a depression scale.
  • Patient must have tried and not responded to at least two different treatments for their symptoms in the past two years, with each treatment lasting at least 8 weeks.
  • Patient must be on a stable dose of Anti-H1 medication for at least 4 weeks before the study and continue this dose during the study. Other treatments must also be stable if used.
  • Patient must be between 18 and 75 years old.
  • Patient must weigh more than 45 kg and have a Body Mass Index (BMI) between 18 and 35.
  • Patient and their partner must use a highly effective method of contraception during the study and for a specified period after the last treatment. This includes methods like hormonal contraception, intrauterine devices, or surgical procedures like tubal ligation or vasectomy.

Who cannot join the trial?

4 criteria

  • Patients who have a different condition than mastocytosis cannot participate. Mastocytosis is a condition where there are too many mast cells in the body.
  • Patients who are not suffering from Smouldering or Indolent Severe Systemic mastocytosis with a handicap that does not respond to the best available treatment cannot participate. This means the condition is not aggressive but still causes significant problems that are not helped by current treatments.
  • Patients who are not within the specified age range cannot participate. The trial is open to certain age groups only.
  • Patients who are part of a vulnerable population cannot participate. This means people who might need special protection or care are not included.
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Investigated drugs

Masitinib is an oral medication being studied for its potential to treat patients with a condition called Smouldering or Indolent Severe Systemic mastocytosis. This condition involves an abnormal accumulation of mast cells in the body, which can lead to various symptoms and complications. The trial aims to determine if masitinib can effectively manage these symptoms in patients who have not responded well to other treatments.

What is already known about the treatment

Masitinib – Masitinib is administered orally and is currently being studied in clinical trials for its effectiveness and safety in treating patients with certain types of systemic mastocytosis, specifically smouldering or indolent severe forms that do not respond to optimal symptomatic treatment. It is in a phase III clinical trial, which means it is being tested for efficacy and safety in a larger group of patients. The main therapeutic indication for masitinib in this trial is systemic mastocytosis, a condition characterized by an abnormal accumulation of mast cells. At the molecular level, masitinib works by inhibiting certain enzymes known as tyrosine kinases, which play a role in the growth and survival of mast cells. It is classified pharmacologically as a tyrosine kinase inhibitor.

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. These cells are part of the immune system and release chemicals like histamine, which can cause symptoms such as itching, flushing, and abdominal pain. The disease can vary in severity, with some individuals experiencing mild symptoms and others having more severe reactions. In systemic mastocytosis, the mast cells accumulate in internal organs, which can lead to more complex symptoms. The progression of the disease can be slow, and symptoms may fluctuate over time. It is considered a rare disease and can present in different forms, including indolent and smouldering systemic mastocytosis.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2024-514538-19-00Protocol codeAB15003Estimated enrolment70 patientsSponsorAb Science

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