Recruiting

Observational Study

Sponsor:

Blueprint Medicines Corporation

Code:

NCT07264959

Conditions

Indolent Systemic Mastocytosis

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Study Details

Brief 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. 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

Study ID

NCT07264959

Start date

Apr 15, 2026

Status verified date

Sep, 2026

Completion date

Dec 1, 2032

Anticipated

Primary completion date

Dec 1, 2032

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

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.

Study Design

Enrollment

150 participants

Anticipated

Interventions and Outcome Measures

Arms

Participants With ISM

Patients who are currently being treated or plan to be treated for ISM

Primary outcome measure

  • 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 ]

Central Contacts and Locations

Central contacts

Blueprint Medicines

1-888-258-7768medinfo@blueprintmedicines.com

Blueprint Medicines, EU Contact

+31 85 064 4001medinfoeurope@blueprintmedicines.com

Locations

University of Colorado

Recruiting

Aurora, Colorado, United States, 80045

Midwest Allergy Sinus Asthma

Recruiting

Normal, Illinois, United States, 61761

Institute for Allergy and Asthma

Recruiting

Wheaton, Maryland, United States, 20902

Brigham and Women's Allergy and Clinical Immunology, Mass General Brigham Healthcare Center (Chestnut Hill)

Recruiting

Chestnut Hill, Massachusetts, United States, 02467

University of Michigan Allergy Clinic

Recruiting

Ann Arbor, Michigan, United States, 48105

Washington University of St. Louis

Recruiting

St Louis, Missouri, United States, 63130

University of Utah

Recruiting

Salt Lake City, Utah, United States, 84112

More Information

Sponsor

Blueprint Medicines Corporation

Last update posted

Sep 4, 2026

Last verified

Sep, 2026

Keywords

  • ISM
  • Avapritinib
  • BLU-285
  • Selective KIT mutation-targeted tyrosine kinase inhibitor
  • Tyrosine kinase inhibitor
  • Mastocytosis
  • Neoplastic mast cells

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-09. This information was provided to ClinicalTrials.gov by Blueprint Medicines Corporation on 2026-09-04.