NCT04996875 · Cogent Biosciences, Inc.
(Apex) Bezuclastinib in Patients With Advanced Systemic Mastocytosis
What this study is about
This is an where both patients and doctors know the treatment given, two-part Phase 2 study investigating CGT9486 for the treatment of patients with Advanced Systemic Mastocytosis (AdvSM), including patients with Aggressive SM (ASM), SM with Associated Hematologic Neoplasm (SM-AHN), and Mast Cell Leukemia (MCL).
View original scientific description
This is an open-label, two-part Phase 2 study investigating CGT9486 for the treatment of patients with Advanced Systemic Mastocytosis (AdvSM), including patients with Aggressive SM (ASM), SM with Associated Hematologic Neoplasm (SM-AHN), and Mast Cell Leukemia (MCL).
Interventions
DRUG
bezuclastinib
Bezuclastinib is administered as tablets to be taken orally, continuously in 28-day cycles.
Primary outcome measures
Part I: Identify clinically active and tolerable exposures of bezuclastinib in patients with AdvSM
Time frame: 18 months
Part II: - Determine efficacy of bezuclastinib as measured by mIWG Objective Response Rate (ORR) - Confirm the exposure-response relationship of bezuclastinib
Time frame: 18 months
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- for Main Study: 1. Diagnosed with one of the following advanced mastocytosis diagnoses by Eligibility Committee 1. Aggressive Systemic Mastocytosis (ASM) 2. Systemic Mastocytosis with an Associated Hematologic Neoplasm (SM-AHN) 3. Mast Cell Leukemia (MCL) 2. Measurable disease according to modified IWG-MRT-ECNM criteria. (A subset of patients inevaluble per mIWG-MRT-ECNM will be included in the study). 3. ECOG (0 to 3) 4. Have clinically acceptable local laboratory screening results (clinical chemistry, hematology) within certain limits Key
Exclusion criteria
- for Main Study: 1. Persistent toxicity from previous therapy for AdvSM that has not resolved to ≤ Grade 1 2. Associated hematologic neoplasm requiring immediate antineoplastic therapy 3. Clinically significant cardiac disease 4. Known positivity for the FIP1L1 PDGFRA fusion. Patients with eosinophilia without detectable KIT D816V mutation must demonstrate lack of PDGFRA fusion mutation prior to
Where
- Birmingham, Alabama
- Phoenix, Arizona
- Duarte, California
- Los Angeles, California
- Stanford, California
- Hialeah, Florida
- Atlanta, Georgia
- Chicago, Illinois
- Boston, Massachusetts
- New York, New York
- Cleveland, Ohio
- Charleston, South Carolina
And 2 more locations — see the full list below.
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced May 5, 2026 · Source of record for eligibility and locations