Recruiting

Observational StudyScreening Study for KIT D816V Mutated Mast Cell Disease in Select Populations

Sponsor:

Blueprint Medicines Corporation

Code:

NCT07143669

Conditions

Clonal Mast Cell Disease

KIT D816V Mutation

Suspected KITD816V Mutated Clonal Mast Cell Disease

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Interventions

Screening

Study Details

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.

Conditions

Clonal Mast Cell Disease

KIT D816V Mutation

Suspected KITD816V Mutated Clonal Mast Cell Disease

Study ID

NCT07143669

Start date

Oct 17, 2025

Status verified date

Aug, 2026

Completion date

Oct 31, 2028

Anticipated

Primary completion date

Jul 31, 2028

Anticipated

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Key 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
History of at least one event of anaphylaxis as determined by the Investigator's clinical assessment and judgment based on available medical history, clinical presentation, and supporting documentation without a clearly identifiable trigger(s) or allergen(s) (otherwise idiopathic anaphylaxis) OR
SMAC-AGS: History of anaphylaxis after eating mammalian meat (e.g. pork, beef) AND history of elevated alpha-gal (galactose-alpha 1, 3 galactose) serum IgE as determined by the Investigator's clinical assessment and supporting medical history documentation 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.
Cohort 4 participants must have documented diagnosis of Mastocytosis in the Skin (MIS) with previously undetected KIT D816V mutation in peripheral blood (PB) or bone marrow (BM) OR Diagnosed cutaneous mastocytosis or physical examination findings indicative of "cutaneous mastocytosis".

Key Exclusion Criteria:

Participants previously diagnosed with any of the following:

1. Monoclonal mast cell activation syndrome with a known KIT mutation
2. Any subtype of systemic mastocytosis
3. 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

Enrollment

750 participants

Anticipated

Interventions and Outcome Measures

Arms

Cohort 1

Participants with symptoms of mast cell activation

Cohort 2

Participants with select diseases with suspected clonal mast cell involvement

Cohort 3

Participants with chronic myelomonocytic leukemia (CMML), or myelodysplastic syndrome/myeloproliferative neoplasm not otherwise specified (MDS/MPN-NOS)

Cohort 4

Participants with cutaneous mast cell involvement

Interventions

Screening

After providing informed consent and relevant medical history data, samples will be collected from participants with suspected clonal mast cell disease.

Primary outcome measure

Proportion of Participants in Cohort 1 with KIT D816V Mutation in Peripheral Blood as Measured by Digital Droplet Polymerase Chain Reaction (ddPCR) [ Time Frame: Day 1 ]
Proportion of Participants in Cohort 1 with KIT D816V Mutation in Peripheral Blood as Measured by Ultra-sensitive KIT D816V by Super Rolling Circle Amplification (superRCA) Assay [ Time Frame: Day 1 ]

Central Contacts and Locations

Central contacts

Blueprint Medicines

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

Blueprint Medicines, EU Contact

+31 85 064 4001 medinfoeurope@blueprintmedicines.com

Locations

AllerVie Clinical Research

Recruiting

Birmingham, Alabama, United States, 35209

O'Neal Comprehensive Cancer Center at the UAB

Recruiting

Birmingham, Alabama, United States, 35294

Kaiser Permanente San Diego

Recruiting

San Diego, California, United States, 92123

Allergy & Asthma Clinical Research of the Bay Area

Recruiting

Walnut Creek, California, United States, 94598

Allergy, Asthma, & Immunology Associates of Tampa Bay

Recruiting

Tampa, Florida, United States, 33613

Emory University

Recruiting

Atlanta, Georgia, United States, 30322

Northwestern Medicine Allergy and Immunology

Recruiting

Evanston, Illinois, United States, 60208

Midwest Allergy Sinus Asthma

Recruiting

Normal, Illinois, United States, 61761

University of Kansas Medical Center

Recruiting

Kansas City, Kansas, United States, 66160

Tulane University School of Medicine

Recruiting

New Orleans, Louisiana, United States, 70112

AllerVie Health

Recruiting

Glenn Dale, Maryland, United States, 20769

Mayo Clinic Rochester

Recruiting

Rochester, Minnesota, United States, 55905

Barnes-Jewish West County Hospital

Recruiting

St Louis, Missouri, United States, 63141

Somnos Clinical Research

Recruiting

Lincoln, Nebraska, United States, 68510

University of Nebraska

Recruiting

Omaha, Nebraska, United States, 68588

Mount Sinai Hospital

Recruiting

New York, New York, United States, 10029

The University of North Carolina at Chapel Hill

Recruiting

Chapel Hill, North Carolina, United States, 27599

Allergy, Asthma & Clinical Research Center

Recruiting

Oklahoma City, Oklahoma, United States, 73120

Allergy & Clinical Immunology Associates

Recruiting

Pittsburgh, Pennsylvania, United States, 15241

Care Access Research

Recruiting

Warwick, Rhode Island, United States, 02886

Medical University of South Carolina

Recruiting

Charleston, South Carolina, United States, 29425

AIR Care

Recruiting

Dallas, Texas, United States, 75231

More Information

Sponsor

Blueprint Medicines Corporation

Last update posted

Aug 12, 2026

Last verified

Aug, 2026

Keywords

Mast Cell Activation Disorder
MDS/MPN Overlap Syndrome
Chronic Myelomonocytic Leukemia
Hypermobility Syndrome Disorder
Postural Orthostatic Tachycardia Syndrome
Early Onset Osteoporosis
Alpha-Gal Syndrome
Cutaneous Mastocytosis

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 2026-08-12.