Indolent Systemic MastocytosisNCT07264959
An Observational Study in Participants With Indolent Systemic Mastocytosis (ISM)
An observational study of Indolent Systemic Mastocytosis, run by Blueprint Medicines Corporation at 7 sites in United States.
Trial summary
This is a Phase 4, non-interventional, observational study to collect detailed data on the clinical characteristics, clinical outcomes and medical management of ISM in real-world settings. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Indolent Systemic Mastocytosis
- How many people
- 150 participants
- Where
- 7 sitesUnited States
- Study dates
- 15 Apr 2026to 1 Dec 2032
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Participants with ISM who are currently being treated or plan to be treated with symptom-directed therapies and/or avapritinib for ISM.
Who may be able to join
- Male or female adult participants (≥ 18 years of age) with a diagnosis of ISM according to the World Health Organization (WHO) diagnostic criteria
- Participant is currently being treated or plans to be treated with symptom-directed therapies and/or avapritinib for ISM.
Who cannot join
- Participants with advanced systemic mastocytosis (AdvSM) or another associated hematologic neoplasm
- Participants with smoldering systemic mastocytosis
- Ongoing participation in interventional studies in systemic mastocytosis (SM) at the time of enrollment
- Participants currently receiving treatment with a KIT inhibitor other than avapritinib at the time of enrollment.
Trial locations and contacts
7 sites in 1 country. Contact the study team or a site near you to ask about taking part.
7 sites in 1 country
United States7 sites, 7 recruiting
- Recruiting
University of Michigan Allergy Clinic
Ann Arbor, Michigan, 48105
- Recruiting
University of Colorado
Aurora, Colorado, 80045
- Recruiting
Brigham and Women's Allergy and Clinical Immunology, Mass General Brigham Healthcare Center (Chestnut Hill)
Chestnut Hill, Massachusetts, 02467
- Recruiting
Midwest Allergy Sinus Asthma
Normal, Illinois, 61761
- Recruiting
University of Utah
Salt Lake City, Utah, 84112
- Recruiting
Washington University of St. Louis
St Louis, Missouri, 63130
- Recruiting
Institute for Allergy and Asthma
Wheaton, Maryland, 20902
About this study
Official title: An Observational Study in Patients With Indolent Systemic Mastocytosis
This is a Phase 4, non-interventional, observational study to collect detailed data on the clinical characteristics, clinical outcomes and medical management of ISM in real-world settings. The study will describe the demographic and clinical characteristics of ISM participants, including anaphylaxis and bone manifestations in ISM. Quality of life and disease control will be assessed through participant questionnaires. The study will also evaluate real world ISM treatment management, including use of avapritinib.
- Conditions
- Indolent Systemic Mastocytosis
- Keywords
- ISM, Avapritinib, BLU-285, Selective KIT mutation-targeted tyrosine kinase inhibitor, Tyrosine kinase inhibitor, Mastocytosis, Neoplastic mast cells
- Medical subject headings
- Mastocytosis, Systemic, Mastocytosis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Participants With ISM | Patients who are currently being treated or plan to be treated for ISM |
What is being measured
The primary outcome is the main question the study is designed to answer.
Baseline Demographics
Measured: Baseline (Month 1)
Change From Baseline in Patient-Reported Outcomes Scores
Measured: Baseline up to Month 61
Change From Baseline in Serum KIT D816V Variant Allele Frequency (VAF)
Measured: Baseline up to Month 61
Change From Baseline in Serum Tryptase
Measured: Baseline up to Month 61
Change From Baseline in Indolent Systemic Mastocytosis (ISM) Symptom-Directed Therapies
Measured: Baseline up to Month 61
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 Dec 2025
- Study start15 Apr 2026
- Primary completion1 Dec 2032 (estimated)
- Study completion1 Dec 2032 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Indolent Systemic MastocytosisStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 150 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Blueprint Medicines Corporation
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07264959
- Sponsor's protocol ID
- BLU-285-2406
- Status last verified
- Sep 2026
- First submitted
- 24 Nov 2025
- Last updated
- 4 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
Study at a glance
From the registry record, last updated by the sponsor on 4 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- An Observational Study in Patients With Indolent Systemic Mastocytosis
- ClinicalTrials.gov ID
- NCT07264959
- Acronym / sponsor ID
- BLU-285-2406
- Conditions
- Indolent Systemic Mastocytosis
- Keywords
- ISM, Avapritinib, BLU-285, Selective KIT mutation-targeted tyrosine kinase inhibitor, Tyrosine kinase inhibitor, Mastocytosis, Neoplastic mast cells
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 150 participants (estimated)
- Lead sponsor
- Blueprint Medicines CorporationIndustry (pharma, biotech, devices)
- Study start
- 15 Apr 2026 (actual)
- Primary completion
- 1 Dec 2032 (estimated)
- Study completion
- 1 Dec 2032 (estimated)
- First posted
- 4 Dec 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This is a Phase 4, non-interventional, observational study to collect detailed data on the clinical characteristics, clinical outcomes and medical management of ISM in real-world settings. The study will describe the demographic and clinical characteristics of ISM participants, including anaphylaxis and bone manifestations in ISM. Quality of life and disease control will be assessed through participant questionnaires. The study will also evaluate real world ISM treatment management, including use of avapritinib.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Participants With ISM | – | –Patients who are currently being treated or plan to be treated for ISM |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Participants with ISM who are currently being treated or plan to be treated with symptom-directed therapies and/or avapritinib for ISM.
Key inclusion criteria (2 listed)
- Male or female adult participants (≥ 18 years of age) with a diagnosis of ISM according to the World Health Organization (WHO) diagnostic criteria
- Participant is currently being treated or plans to be treated with symptom-directed therapies and/or avapritinib for ISM.
Key exclusion criteria (4 listed)
- Participants with advanced systemic mastocytosis (AdvSM) or another associated hematologic neoplasm
- Participants with smoldering systemic mastocytosis
- Ongoing participation in interventional studies in systemic mastocytosis (SM) at the time of enrollment
- Participants currently receiving treatment with a KIT inhibitor other than avapritinib at the time of enrollment.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Baseline Demographics
Time frame: Baseline (Month 1)
Change From Baseline in Patient-Reported Outcomes Scores
Time frame: Baseline up to Month 61
Change From Baseline in Serum KIT D816V Variant Allele Frequency (VAF)
Time frame: Baseline up to Month 61
Change From Baseline in Serum Tryptase
Time frame: Baseline up to Month 61
Change From Baseline in Indolent Systemic Mastocytosis (ISM) Symptom-Directed Therapies
Time frame: Baseline up to Month 61
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 4 Sep 2026.
Related trials for Indolent Systemic Mastocytosis
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(HARBOR) Study to Evaluate Efficacy and Safety of BLU-263 Versus Placebo in Patients With Indolent Systemic Mastocytosis
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A Non-Interventional Study in Participants With Indolent Systemic Mastocytosis (ISM) in Germany
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(PIONEER) Study to Evaluate Efficacy and Safety of Avapritinib (BLU-285), A Selective KIT Mutation-targeted Tyrosine Kinase Inhibitor, Versus Placebo in Patients With Indolent Systemic Mastocytosis
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
7 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Indolent Systemic Mastocytosis, run by Blueprint Medicines Corporation at 7 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 4 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 7 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Blueprint Medicines (1-888-258-7768, medinfo@blueprintmedicines.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Baseline Demographics (time frame: Baseline (Month 1)). The study lists 5 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 4 Sep 2026.