An observational study in Indolent Systemic Mastocytosis, sponsored by Blueprint Medicines Corporation. Recruiting at 7 sites in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-09-04.
Sponsored by Blueprint Medicines Corporation (part of Sanofi) · Observational
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.
56 studies on the registry are indexed under Mastocytosis, Systemic; 16 are open to participants now.
This study's planned enrollment of 150 is close to the median of 155 across 18 observational studies indexed under Mastocytosis, Systemic.
Browse Mastocytosis, Systemic studies →Blueprint Medicines Corporation is the lead sponsor of 32 studies on the registry; 6 are open to participants now.
Of its 14 completed or terminated interventional studies of FDA-regulated products, 3 (21%) have results posted.
First submitted after Blueprint Medicines Corporation became part of Sanofi.
Counted across the registry records on this site, refreshed daily.
Participants with ISM who are currently being treated or plan to be treated with symptom-directed therapies and/or avapritinib for ISM.
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Exclusion Criteria:
Patients who are currently being treated or plan to be treated for ISM
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
Started Apr 2026 (actual). Primary completion is estimated for Dec 2032, 79 months after the start.
How these figures are worked out, and which studies are left out of them.
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Blueprint Medicines Corporation →