Screening Study for KIT D816V Mutated Mast Cell Disease in Select Populations

Not yet recruiting

• Conditions: Clonal Mast Cell Disease; KIT D816V Mutation; Suspected KITD816V Mutated Clonal Mast Cell Disease

• Registration Number: NCT07143669
• Lead Sponsor: Blueprint Medicines Corporation

Brief Summary

This is a multicenter screening study to characterize the prevalence of the KIT D816V mutation in participants with suspected clonal mast cell disease.

Detailed Description

Not available

Study Timeline

• Status Verified: 2025-08
• Study First Submitted: 2025-08-20
• Study First Submitted QC: 2025-08-20
• Last Update Submitted: 2025-08-20
• Study First Posted: 2025-08-27
• Last Update Posted: 2025-08-27
• Study Start: 2025-09-30
• Primary Completion: 2028-07-31
• Study Completion: 2028-10-31

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: All
• Target Recruitment: 450

Inclusion Criteria

• Cohort 1 participants must meet inclusion criteria for either SMAC-A or SMAC-B:

  1. SMAC-A

• Documented anaphylaxis due to Hymenoptera venom with cardiovascular symptoms or

• Documented anaphylaxis without known trigger(s) or allergen(s) warranting hospitalization, emergency room visit, and/or epinephrine with cardiovascular symptoms 2. SMAC-B

• Episodic or recurrent signs and symptoms consistent with mast cell activation without known triggers or allergens in at least 2 of the following organ systems: skin, respiratory/naso-ocular, gastrointestinal tract, or cardiovascular.

• Any clinical response on one or more optimally dosed therapies intended to mitigate mast cell mediators, as determined by the Investigator.

• Cohort 2 participants must have confirmed, known diagnosis of 1 of the following criteria:

  1. Either hypermobile Ehlers-Danlos syndrome or documented history of hypermobility spectrum disorder.
  2. Postural orthostatic tachycardia syndrome with one or more systemic symptoms.
  3. Early onset (≤50 years old) osteoporosis or osteopenia.

• Cohort 3 participants must have documented diagnosis of 1 of the following, according to World Health Organization 5th edition criteria: chronic myelomonocytic leukemia or myelodysplastic syndrome/myeloproliferative neoplasm not otherwise specified.

Key

Exclusion Criteria

• Participants previously diagnosed with any of the following:

  1. Monoclonal mast cell activation syndrome with a known KIT mutation
  2. Cutaneous mastocytosis only (that is, no documentation of systemic mast cell disease via bone marrow biopsy)
  3. Any subtype of systemic mastocytosis
  4. Mast cell sarcoma

• Cohort 2 only: Osteopenia or osteoporosis attributed to known genetic, endocrine, nutritional, or other medical conditions.

Note: Additional protocol-defined criteria apply.

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Proportion of Participants in Cohort 1 with KIT D816V Mutation in Peripheral Blood as Measured by Digital Droplet Polymerase Chain Reaction (ddPCR)	Day 1
Proportion of Participants in Cohort 1 with KIT D816V Mutation in Peripheral Blood as Measured by Ultra-sensitive KIT D816V by Rolling Circle Amplification (RCA) Assay	Day 1