An Observational Study in Participants With Indolent Systemic Mastocytosis (ISM)

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.

NCT Number	NCT07264959
Lead Sponsor	Blueprint Medicines Corporation
Conditions	Indolent Systemic Mastocytosis
Enrollment	150 participants
Start Date	2026-04-15
Primary Completion	2032-12-01 (estimated)
Study Completion	2032-12-01 (estimated)
Updated on ClinicalTrials.gov	2026-08-04