Real-world care and outcomes for people with indolent systemic mastocytosis (ISM)

An Observational Study in Patients With Indolent Systemic Mastocytosis

Observational Blueprint Medicines Corporation · NCT07264959

This study will see how people with ISM are treated and how they are doing in everyday care, including those taking avapritinib.

Quick facts

Study typeObservational
Enrollment150 (estimated)
Ages18 Years and up
SexAll
SponsorBlueprint Medicines Corporation Industry-sponsored
Drugs / interventionsavapritinib
Locations1 site (Chestnut Hill, Massachusetts)
Trial IDNCT07264959 on ClinicalTrials.gov

What this trial studies

This Phase 4, non-interventional observational program will collect detailed clinical and treatment data from adults with WHO-diagnosed indolent systemic mastocytosis. Investigators will record demographics, clinical features such as anaphylaxis and bone manifestations, treatments used in routine practice, and participant-reported quality of life and disease control via questionnaires. The study specifically includes participants treated or planning treatment with symptom-directed therapies and/or avapritinib and excludes those with advanced or smoldering disease, other hematologic neoplasms, or use of non-avapritinib KIT inhibitors. Data will be gathered from medical records and participant questionnaires to characterize real-world management and outcomes over time.

Who should consider this trial

Good fit: Adults aged 18 or older with a WHO diagnosis of indolent systemic mastocytosis who are currently being treated or plan to be treated with symptom-directed therapies and/or avapritinib are ideal candidates.

Not a fit: People with advanced systemic mastocytosis, smoldering systemic mastocytosis, another associated hematologic neoplasm, those enrolled in interventional SM trials, or those receiving a KIT inhibitor other than avapritinib are excluded and unlikely to benefit from this study.

Why it matters

Potential benefit: If successful, the study could improve understanding of how ISM is managed in real life and help guide treatment decisions and supportive care for patients.

How similar studies have performed: Observational registries and real-world studies in mast cell disorders have provided useful clinical insights and safety signals, and clinical trials have shown benefit of KIT-targeted agents in related forms, but prospective ISM-specific real-world data remain limited.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* 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.

Exclusion Criteria:

* 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.

Where this trial is running

Chestnut Hill, Massachusetts

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Indolent Systemic MastocytosisISMAvapritinibBLU-285Selective KIT mutation-targeted tyrosine kinase inhibitorTyrosine kinase inhibitorMastocytosisNeoplastic mast cells
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.