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Study of Avapritinib for Patients with Indolent Systemic Mastocytosis Not Adequately Managed by Standard Therapy

Fast replyInvestigationalNo 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 a condition called Indolent Systemic Mastocytosis (ISM), which is a type of disease where certain cells in the body, known as mast cells, grow uncontrollably and cause various symptoms. The trial is testing a medication called Avapritinib, which is a type of drug known as a tyrosine kinase inhibitor. This medication is designed to target specific mutations in the KIT gene that are often found in patients with ISM. The study also involves the use of a placebo, which is a substance with no active medication, to compare the effects of Avapritinib.

The purpose of the study is to evaluate the safety and effectiveness of Avapritinib in patients with ISM whose symptoms are not adequately controlled with standard treatments. The study is divided into three parts. In the first part, the appropriate dose of Avapritinib will be determined. The second part will compare the change in symptoms from the start of the study to a specific point in time between those taking Avapritinib and those taking a placebo. The third part will assess the long-term safety and effectiveness of Avapritinib in these patients.

Participants in the study will take Avapritinib in the form of film-coated tablets, which are taken orally. The study will monitor changes in symptoms, the burden of mast cells in the body, and the overall quality of life of the participants. Safety will be closely monitored through regular assessments, including checking vital signs, conducting electrocardiograms (ECGs), and performing laboratory tests. The study aims to provide valuable information on how well Avapritinib works in managing ISM and its long-term safety for patients.

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

    Joining the study

    Upon joining the study, you will be randomly assigned to one of the study groups. This means you may receive either the actual medication, avapritinib, or a placebo, which looks like the medication but does not contain the active ingredient.

  2. Step 2

    Part 1: determining dosage

    In this initial phase, the goal is to determine the right dose of avapritinib for further study. You will take the medication orally in the form of a film-coated tablet. The specific dosage and frequency will be provided by the study team.

  3. Step 3

    Part 2: evaluating symptoms

    During this phase, the study will focus on how your symptoms change from the beginning of the study to a specific point, known as C7D1. You will continue to take the medication or placebo as directed.

  4. Step 4

    Part 3: long-term assessment

    This phase assesses the long-term safety and effectiveness of avapritinib. You will continue to take the medication or placebo, and your health and symptoms will be monitored over an extended period.

  5. Step 5

    Regular health assessments

    Throughout the study, regular health assessments will be conducted. These may include checking vital signs, performing electrocardiograms (heart tests), and conducting laboratory tests to ensure your safety and monitor any side effects.

  6. Step 6

    Completion of the study

    At the end of the study, you will have a final assessment to evaluate your overall health and any changes in your symptoms. The study team will provide you with information about your participation and any next steps.

Who can join the trial?

8 criteria

  • Patients must be 18 years of age or older.
  • Patients must have a condition called Systemic Mastocytosis (SM), confirmed by a special review of a bone marrow biopsy and other findings according to specific criteria.
  • Patients must have moderate-to-severe symptoms based on a specific symptom score over a 14-day period. The minimum score for eligibility is 28.
  • Patients must have tried at least two different treatments for their symptoms, such as H1 blockers (like antihistamines), H2 blockers (like stomach acid reducers), proton-pump inhibitors (another type of stomach acid reducer), leukotriene inhibitors (medications that block substances that cause allergy symptoms), cromolyn sodium (a medication that prevents allergic reactions), corticosteroids (anti-inflammatory drugs), or omalizumab (a medication for allergic asthma), but did not achieve adequate symptom control.
  • The patient's current treatments for SM symptoms must be stable (same dose, no new medications) for at least 14 days before starting the 14-day symptom score assessment.
  • If the patient is taking corticosteroids, the dose must be 20 mg/day or less of prednisone or an equivalent medication, and the dose must be stable for at least 14 days before starting the 14-day symptom score assessment.
  • Patients must have an ECOG Performance Status of 0 to 2, which is a scale used to assess how a patient's disease is progressing and how the disease affects their daily living abilities.
  • Patients must be able to give written informed consent, meaning they understand the study and agree to participate.

Who cannot join the trial?

7 criteria

  • Patients who do not have Indolent Systemic Mastocytosis (ISM) cannot participate. ISM is a condition where certain cells in the body grow too much and release chemicals that can cause symptoms like itching or stomach problems.
  • Patients who are not within the specified age range for the study cannot participate. The study is open to certain age groups only.
  • Patients who are not willing or able to follow the study procedures cannot participate. This means they must be able to attend all appointments and follow instructions given by the study team.
  • Patients who have other medical conditions that might interfere with the study cannot participate. This is to ensure the safety of the participants and the accuracy of the study results.
  • Patients who are taking medications that might interfere with the study cannot participate. Some medications can affect how the study drug works or cause unwanted side effects.
  • Patients who are pregnant or breastfeeding cannot participate. This is to protect the health of the mother and the baby.
  • Patients who have participated in another clinical trial recently cannot participate. This is to avoid any interference with the results of this study.
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Investigated drugs

Avapritinib is a medication being studied for its potential to help people with a condition called systemic mastocytosis. This condition involves the buildup of certain cells in the body, which can cause a variety of symptoms. Avapritinib works by targeting specific changes in these cells, known as KIT mutations, which are thought to play a role in the disease. The goal of using Avapritinib in this trial is to see if it can help reduce symptoms that are not well controlled by standard treatments. The study is also looking at how safe the medication is for long-term use in patients with this condition.

What is already known about the treatment

Avapritinib – Avapritinib is a medication administered orally in the form of a tablet. It is currently being studied in clinical trials for its effectiveness in treating Indolent Systemic Mastocytosis (ISM), a condition where certain immune cells build up in the body. Avapritinib works by specifically targeting and inhibiting a protein called KIT, which is often mutated in ISM, helping to control the symptoms that are not managed by standard treatments. It belongs to a class of drugs known as tyrosine kinase inhibitors, which are designed to block the action of enzymes involved in the growth of cancer cells.

Investigated diseases

Indolent Systemic Mastocytosis (ISM) – Indolent Systemic Mastocytosis is a condition characterized by an abnormal accumulation of mast cells in various tissues, including the skin, bone marrow, and internal organs. These mast cells release substances that can cause symptoms such as skin lesions, itching, and gastrointestinal discomfort. The disease progresses slowly and is often associated with mild symptoms. Over time, patients may experience an increase in the number of mast cells, leading to more pronounced symptoms. The condition is considered a chronic disorder, with periods of symptom flare-ups and remissions. It is classified as a rare disease, affecting a small percentage of the population.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IITrial ID2024-512585-34-00Protocol codeBLU-285-2203Estimated enrolment251 patientsSponsorBlueprint Medicines Corp.

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