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Study of Avapritinib for Adults with Systemic Mastocytosis Who Previously Participated in an Avapritinib Study

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What is this trial about?

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

This clinical trial focuses on a condition known as Systemic Mastocytosis, which is a rare disorder where there is an abnormal accumulation of mast cells in various parts of the body. The study involves a medication called Avapritinib, also known by its code name BLU-285. Avapritinib is provided in the form of a film-coated tablet and is taken orally.

The purpose of this study is to allow patients who have previously participated in an Avapritinib clinical study to continue receiving the medication until it becomes commercially available. This is intended for patients who have been benefiting from the treatment, as determined by their doctor. The study is open-label, meaning both the researchers and participants know what treatment is being administered.

Participants in this study will continue to take Avapritinib as they did in their previous study. The study will last until the medication is commercially available, or until the participant no longer benefits from the treatment. This trial is designed to ensure that patients who have shown positive results with Avapritinib can maintain their treatment without interruption.

The research process

The trial runs in 4 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Enrollment

    Participation in a previous avapritinib study is required. Continued clinical benefit from avapritinib treatment must be confirmed by the investigator.

    Written informed consent is necessary before enrolling in the study and receiving treatment. If written consent is not possible, it must be documented and witnessed by an independent trusted witness.

  2. Step 2

    Treatment continuation

    The study provides ongoing access to avapritinib in the form of a film-coated tablet for oral use.

    The dosage and frequency of avapritinib administration will be determined by the investigator based on the patient's previous treatment regimen.

  3. Step 3

    Monitoring and assessments

    Regular monitoring and assessments will be conducted to evaluate the patient's response to avapritinib and ensure continued clinical benefit.

    Female patients of childbearing potential must have a negative pregnancy test within 20 days before the first dose of avapritinib.

  4. Step 4

    Study duration

    The study is estimated to continue until December 31, 2027, or until avapritinib becomes commercially available.

    Participation in the study is contingent upon continued clinical benefit from avapritinib as judged by the investigator.

Who can join the trial?

6 criteria

  • The patient must have participated in a previous clinical study sponsored by Blueprint Medicines involving a drug called **avapritinib** and is either currently receiving the drug or has had a temporary break from it. If the break has been longer than 56 days, a medical expert should be consulted before starting the drug again.
  • The patient must have completed the final visit of the previous study and followed all the study requirements, as checked by the main doctor in charge of the study.
  • The patient must still be benefiting from the treatment with **avapritinib**, as determined by the main doctor from the previous study.
  • The patient must be able to provide written consent, which means they agree to participate in the study after understanding all the details. If they cannot write, their consent must be formally recorded and witnessed by someone trustworthy.
  • The patient must agree to continue using very effective birth control methods as described in the study guidelines.
  • Female patients who can have children must have a negative pregnancy test within 20 days before the first dose of **avapritinib**. This test checks for a hormone called **beta human chorionic gonadotropin (β-hCG)**, which indicates pregnancy. If the test shows a false positive, meaning it suggests pregnancy when there is none, the patient can still join the study with written approval after confirming they are not pregnant. Women who cannot have children (due to menopause or certain surgeries) do not need this test.

Who cannot join the trial?

5 criteria

  • Patients who have not participated in a Blueprint Medicines sponsored study.
  • Patients who do not continue to benefit from treatment with avapritinib, as determined by the study doctor.
  • Patients who are not diagnosed with Systemic Mastocytosis, a condition where certain cells in the body grow uncontrollably.
  • Patients who are younger than 3 years old.
  • Patients who are not part of the specified clinical trial groups.
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Investigated drugs

Avapritinib is a medication used in this clinical trial to provide continued treatment for patients who have previously participated in a study involving this drug. It is intended for patients who are still benefiting from the treatment, as determined by their doctor. The trial aims to ensure that these patients have access to avapritinib until it becomes commercially available.

What is already known about the treatment

Avapritinib – Avapritinib is administered orally in the form of tablets. It is currently being studied in clinical trials and is not yet commercially available, but it is accessible to patients who have participated in previous studies and continue to benefit from it. The main therapeutic indication for avapritinib is systemic mastocytosis, a condition characterized by an abnormal accumulation of mast cells. At the molecular level, avapritinib works by inhibiting specific enzymes known as kinases, which play a role in cell growth and survival. It is classified pharmacologically as a kinase inhibitor.

Investigated diseases

Systemic Mastocytosis – Systemic Mastocytosis is a disorder characterized by an abnormal accumulation of mast cells in various tissues, including the skin, bone marrow, liver, and spleen. These mast cells release chemicals like histamine, which can cause symptoms such as skin rashes, itching, abdominal pain, and anaphylaxis. The disease can vary in severity, with some individuals experiencing mild symptoms and others having more severe complications. Over time, the accumulation of mast cells can lead to organ dysfunction. The progression of the disease can be slow, and symptoms may fluctuate. It is considered a rare condition, affecting a small percentage of the population.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2024-514969-18-00Protocol codeBLU-285-2404Estimated enrolment84 patientsSponsorBlueprint Medicines Corp.

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