(PROSPECTOR) Screening Study Evaluating the Prevalence of the KIT D816V Mutation in Patients With Systemic Mast Cell Activation

Study Evaluating the Prevalence of the KIT D816V Mutation in Peripheral Blood of Patients With Evidence of Systemic Mast Cell Activation (MCA)

This is a multi-center screening study with the primary objective to determine the prevalence of KIT D816V mutation in peripheral blood in patients with evidence of systemic mast cell activation (MCA).

Study Overview

• Status: Completed
• Conditions: Systemic Mast Cell Activation; KIT D816V Mutation
• Intervention / Treatment: Other: Screening

• Study Type: Observational
• Enrollment (Actual): 379

Contacts and Locations

Study Locations

• Belgium
  • Edegem, Belgium, 2650
    • Antwerp University Hospital UZA
• France
  • Paris, France, 75013
    • Pitié-Salpêtrière Hospital
  • Toulouse, France, 31059
    • Chu Toulouse
• Germany
  • Berlin, Germany, 12203
    • Charité Universitätsmedizin Berlin
  • Hannover, Germany, 30625
    • Medizinische Hochschule Hannover, Dept. of Dermatology and Allergy
  • Munchen, Germany, 80337
    • Klinik fuer Dermatologie und Allergologie
• Italy
  • Salerno, Italy, 84100
    • AOU San Giovanni di Dio e Ruggi d'Aragona University of Salerno
  • Verona, Italy, 37126
    • Azienda Ospedaliera Universitaria Integrata Verona
• Spain
  • Toledo, Spain, 45071
    • Hospital Virgen del Valle
• Switzerland
  • Basel, Switzerland, 4031
    • University of Basel
• United Kingdom
  • Leicester, United Kingdom, LE1 5WW
    • University Hospital of Leicester
  • London, United Kingdom, SE1 9RT
    • Guy's and St Thomas' NHS Foundation Trust
  • Plymouth, United Kingdom, PL6 8DH
    • University Hospitals Plymouth NHS Trust
• United States
  • Alabama
    • Birmingham, Alabama, United States, 35209
      • Clinical Research Center of Alabama
  • California
    • San Diego, California, United States, 92130
      • Scripps Clinic Carmel Valley
  • Massachusetts
    • Boston, Massachusetts, United States, 02115
      • Brigham and Women's Hospital
  • Michigan
    • Ann Arbor, Michigan, United States, 48105
      • University of Michigan
  • Minnesota
    • Rochester, Minnesota, United States, 55905
      • Mayo Clinic
  • New York
    • Buffalo, New York, United States, 14203
      • Roswell Park Cancer Center
    • New Paltz, New York, United States, 12561
      • Albert P. Hirdt D.O. P.C.
    • New York, New York, United States, 10032
      • Columbia University Medical Center - Herbert Irving Comprehensive Cancer Center HICCC
  • North Carolina
    • Durham, North Carolina, United States, 27705
      • Duke University: Duke Allergy Asthma Airway Center
  • Ohio
    • Cincinnati, Ohio, United States, 45236
      • Bernstein Clinical Research Center, LLC

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Adult patients with systemic mast cell activation

Description

Inclusion Criteria:

• Presenting with at least one of the three criteria below as evidence of systemic mast cell activation:

  1. Involvement of 2 or more organ systems, characterized by skin (pruritus, urticaria, flushing and angioedema), cardiovascular (tachycardia, syncope, and hypotension), gastrointestinal (diarrhea, nausea, vomiting, and gastrointestinal cramping) or respiratory/naso-ocular (wheezing, conjunctival injection, and nasal stuffiness) AND serum basal tryptase levels ≥8 ng/ml. One of the organ systems must be the cardiovascular system.
  2. Severe anaphylaxis (Ring and Messmer grading ≥II) due to Hymenoptera sting, regardless of serum basal tryptase levels.
  3. Severe anaphylaxis (Ring and Messmer grading ≥II), with cardiovascular involvement and documented event-related tryptase elevation fitting the formula 20% of baseline plus 2 ng/ml evaluated in at least 1 event.

Exclusion Criteria:

• Patient previously diagnosed with any of the following WHO systemic mastocytosis (SM) sub-classifications: mastocytosis in the skin, indolent SM, smoldering SM, SM with associated hematological neoplasm, aggressive SM, mast cell leukemia, mast cell sarcoma

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Proportion of patients with KIT D816V mutation in peripheral blood	Day 1

Secondary Outcome Measures

Outcome Measure	Time Frame
Mean KIT D816V mutated allele fraction in peripheral blood	Day 1
Proportion of patients with increased tryptase Alpha/ Beta 1 (TPSAB1) alpha-tryptase gene copy number (GCN) in buccal mucosa	Day 1

Collaborators and Investigators

• Sponsor: Blueprint Medicines Corporation

Study record dates

Study Major Dates

• Study Start (Actual): June 29, 2021
• Primary Completion (Actual): March 31, 2023
• Study Completion (Actual): March 31, 2023

Study Registration Dates

• First Submitted: March 10, 2021
• First Submitted That Met QC Criteria: March 19, 2021
• First Posted (Actual): March 23, 2021

Study Record Updates

• Last Update Posted (Actual): April 6, 2023
• Last Update Submitted That Met QC Criteria: April 4, 2023
• Last Verified: April 1, 2023

More Information

Terms related to this study

• Other Study ID Numbers: BLU-SM-1101

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No