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Study of Elenestinib (BLU-263) in Advanced Systemic Mastocytosis (AdvSM) and and Other KIT Altered Hematologic Malignancies

Phase 1
Terminated
Conditions
Advanced Systemic Mastocytosis
Interventions
Registration Number
NCT05609942
Lead Sponsor
Blueprint Medicines Corporation
Brief Summary

The goal of this clinical trial is to evaluate elenestinib (BLU-263) in participants with Advanced Systemic Mastocytosis (AdvSM), SM with an associated hematologic neoplasm (SM-AHN), and other hematologic malignancies. The main questions it aims to answer are:

* Determine Recommended Dose of elenestinib (BLU-263) monotherapy for participants with AdvSM

* Safety and tolerability of elenestinib (BLU-263) monotherapy

* Efficacy of elenestinib (BLU-263) monotherapy in participants with AdvSM

* Determine Recommended Dose of elenestinib (BLU-263) in combination with azacitidine in participants with AdvSM

* Safety and tolerability of elenestinib (BLU-263) in combination with azacitidine

* Efficacy of elenestinib (BLU-263) in combination with azacitidine in participants with AdvSM

The estimated study duration for each participant will be approximately 4 years: 2 years of treatment followed by 2 years of follow-up. Participants may be required to attend monthly visits for the first six months, followed by quarterly visits for the remainder of the study.

Detailed Description

Systemic mastocytosis includes five major subtypes: Indolent SM (ISM), SM with an associated hematologic neoplasm (SM-AHN), aggressive SM (ASM), and MC leukemia (MCL). In 2016, the smoldering subtype of SM, a former provisional ISM subvariant, was designated as a distinct variant of SM by the World Health Organization (WHO). Aggressive SM, SM-AHN, and MCL together are referred to as Advanced SM (AdvSM).

Recruitment & Eligibility

Status
TERMINATED
Sex
All
Target Recruitment
9
Inclusion Criteria

Not provided

Exclusion Criteria
  • Diagnosis of a Philadelphia chromosome positive malignancy
  • Acute myeloid leukemia.
  • If the participant is receiving corticosteroids, and the dose has not been stable for ≥7 days.
  • Within the 14 days prior to enrollment, participant has received any antineoplastic therapy (including midostaurin, avapritinib and other tyrosine kinase inhibitors [TKIs]) or an investigational agent.
  • Participant has received hydroxyurea within 7 days prior to the first dose of elenestinib (BLU-263).
  • Participant received prior HMA therapy (e.g., azacitidine, decitabine) for the current diagnosis.
  • Participant must not be eligible for allogenic hematopoietic stem cell transplantation.
  • Participant received prior radiotherapy within 14 days of screening BM biopsy.
  • Participant received any hematopoietic growth factor (except erythropoietin) within 14 days of screening BM biopsy, or requiring growth factors to maintain adequate neutrophil or platelet levels.

Those participants maintained on a chronic dose of erythropoietin, whose hemoglobin is stable, and dose of erythropoietin has not been changed in the prior 28 days are allowed on study.

  • Participant received >1 prior selective KIT inhibitor (eg: avapritinib or bezuclastinib).
  • Participant have any of the following laboratory abnormalities on last laboratory assessment within 14 days prior to the first dose of initiation of study drug: a. Alanine aminotransferase and aspartate aminotransferase > 3 × ULN; > 5 × ULN if associated with clinically suspected liver infiltration by mastocytosis or another disease for which the patient enrolled into the study b. Total bilirubin > 1.5 × ULN; > 3 × ULN if associated with liver infiltration by the disease being treated or in the presence of Gilbert's Disease. (In the case of Gilbert's disease, a direct bilirubin > 2.0 ULN would be an exclusion) c. Estimated (Cockcroft-Gault formula) or measured creatinine clearance < 40 mL/min d. Absolute neutrophil count < 0.5 × 10^9/L
  • Participant has had a major surgical procedure within 14 days of the first dose of study drug.
  • History of another primary malignancy that has been diagnosed or required therapy within 1 year prior to the first dose of study drug. The following are exempt from the 1-year limit: completely resected basal cell and squamous cell skin cancer, curatively treated localized prostate cancer, GI stromal tumor, and completely resected carcinoma in situ of any site.
  • Mean resting QTcF > 480 msec, a history of prolonged QT syndrome or Torsades de pointes, or a familial history of prolonged QT syndrome.
  • Clinically significant, uncontrolled, cardiovascular disease.

Arm 1 (Monotherapy):

  • Myelodysplastic Syndrome (MDS) that is very high- or high-risk as defined by the International Prognostic Scoring System for Myelodysplastic Syndromes-Revised (IPSS-R).
  • A myeloid AHN with ≥10% BM or peripheral blood blasts.
  • Platelet count <50 x 10^9/L (within 4 weeks prior to the first dose of study drug) or receiving platelet transfusions or thrombopoietin receptor agonists (TPO-RA) within the prior 14 days.

Study & Design

Study Type
INTERVENTIONAL
Study Design
SEQUENTIAL
Arm && Interventions
GroupInterventionDescription
Combination therapyBLU-263Participants with high risk and very high risk systemic mastocytosis with an associated hematologic neoplasm (SM-AHN) of non-MC lineage will receive BLU-263 in combination with azacitidine.
MonotherapyBLU-263Participants with AdvSM (ASM, SM-AHN, or MCL) will receive BLU-263 monotherapy.
Combination therapyAzacitidineParticipants with high risk and very high risk systemic mastocytosis with an associated hematologic neoplasm (SM-AHN) of non-MC lineage will receive BLU-263 in combination with azacitidine.
Primary Outcome Measures
NameTimeMethod
Dose Escalation and Expansion: Number of Participants with Serious Adverse Events (SAEs)Up to approximately 4 years
Dose Escalation: Number of Dose-limiting Toxicities (DLTs) (monotherapy only)28 Days

Monotherapy: The Recommended Dose (RD) will be primarily determined by the number of DLTs in the first 28 days of treatment with elenestinib (BLU-263) monotherapy.

Dose Escalation: Number of DLTs (combination therapy only)28 Days

Combination therapy: The RD will be primarily determined by the number of DLTs (during 28 days starting from Day 15 of C1 or Day 15 of C2) with elenestinib (BLU-263) in combination with azacitidine.

Dose Escalation and Expansion: Pure Pathological Response (PPR) Rate for SM in Selective KIT Inhibitor-naïve Participants (monotherapy only)Up to approximately 4 years

PPR Rate is defined as complete remission (resolution of palpable splenomegaly/hepatomegaly) (CR) + complete remission with partial recovery of peripheral blood counts (CRh) + partial remission (≥35% reduction in spleen volume) (PR)

Dose Escalation and Expansion: Number of Participants with Adverse Events (AEs)Up to approximately 4 years
Secondary Outcome Measures
NameTimeMethod
Dose Escalation and Dose Expansion: t1/2 of Azacitidine (combination therapy only)Up to approximately 4 years
Dose Escalation and Dose Expansion: Maximum Plasma Concentration (Cmax) of BLU-263Up to approximately 4 years
Dose Escalation and Dose Expansion: Time to Maximum Concentration (Tmax) of BLU-263Up to approximately 4 years
Dose Escalation and Expansion: Overall Response Rate (ORR) for AdvSM using modified International Working Group-Myeloproliferative Neoplasms Research and Treatment and European Competence Network on Mastocytosis (IWG-MRT-ECNM) (monotherapy only)Up to approximately 4 years

ORR is defined as CR + CRh + PR + Clinical Improvement (CI)

Dose Escalation and Expansion: ORR for SM Using Modified IWG-MRT-ECNM (combination therapy only)Up to approximately 4 years
Dose Escalation and Dose Expansion: Cmax of Azacitidine (combination therapy only)Up to approximately 4 years
Dose Escalation and Dose Expansion: Area Under the Curve From Time Zero to 24 Hours (AUC(0-24)) of BLU-263Up to approximately 4 years
Dose Escalation and Dose Expansion: Terminal Elimination Half-life (t1/2) of BLU-263Up to approximately 4 years
Dose Escalation and Dose Expansion: CL/F of Azacitidine (combination therapy only)Up to approximately 4 years
Dose Escalation and Dose Expansion: Accumulation Ratio of BLU-263Up to approximately 4 years
Dose Escalation and Expansion: Time to Response (TtR) (monotherapy only)Up to approximately 4 years
Dose Escalation and Expansion: Progression-Free Survival (PFS) (monotherapy only)Up to approximately 4 years
Dose Escalation and Expansion: PPR Rate for SM (combination therapy only)Up to approximately 4 years
Dose Escalation and Dose Expansion: Apparent Volume of Distribution (Vz/F) of BLU-263Up to approximately 4 years
Dose Escalation and Dose Expansion: Apparent Oral Clearance (CL/F) of BLU-263Up to approximately 4 years
Dose Escalation and Expansion: Duration of Response (DOR) (monotherapy only)Up to approximately 4 years
Dose Escalation and Expansion: Proportion of Participants Pursuing Stem Cell Transplant (monotherapy only)Up to approximately 4 years
Dose Escalation and Dose Expansion: Tmax of Azacitidine (combination therapy only)Up to approximately 4 years
Dose Escalation and Dose Expansion: Vz/F of Azacitidine (combination therapy only)Up to approximately 4 years
Dose Escalation and Dose Expansion: AUC(0-24) of Azacitidine (combination therapy only)Up to approximately 4 years
Dose Escalation and Expansion: Overall Survival (OS) (monotherapy only)Up to approximately 4 years
Dose Escalation and Dose Expansion: Accumulation Ratio of Azacitidine (combination therapy only)Up to approximately 4 years

Trial Locations

Locations (22)

Dana-Farber Cancer Institute

🇺🇸

Boston, Massachusetts, United States

University Medical Centre Mannheim

🇩🇪

Mannheim, Germany

Stanford Cancer Institute

🇺🇸

Palo Alto, California, United States

University of Michigan

🇺🇸

Ann Arbor, Michigan, United States

Antwerp University Hospital

🇧🇪

Edegem, Belgium

Huntsman Cancer Institute

🇺🇸

Salt Lake City, Utah, United States

University Hospital Ghent

🇧🇪

Ghent, Belgium

CHU Caen - Institut d'Hematologie de Basse Normandie

🇫🇷

Caen, France

Oslo University Hospital

🇳🇴

Oslo, Norway

Maastricht University Medical Center

🇳🇱

Maastricht, Netherlands

Instituto de Estudios de Mastocitosis de Castilla La Mancha (CLMast)

🇪🇸

Toledo, Spain

Stanford Cancer Institute

🇺🇸

Palo Alto, California, United States

Dana-Farber Cancer Institute

🇺🇸

Boston, Massachusetts, United States

University of Michigan

🇺🇸

Ann Arbor, Michigan, United States

Huntsman Cancer Institute

🇺🇸

Salt Lake City, Utah, United States

Antwerp University Hospital

🇧🇪

Edegem, Belgium

University Hospital Ghent

🇧🇪

Ghent, Belgium

CHU Caen - Institut d'Hematologie de Basse Normandie

🇫🇷

Caen, France

University Medical Centre Mannheim

🇩🇪

Mannheim, Germany

Maastricht University Medical Center

🇳🇱

Maastricht, Netherlands

Oslo University Hospital

🇳🇴

Oslo, Norway

Instituto de Estudios de Mastocitosis de Castilla La Mancha (CLMast)

🇪🇸

Toledo, Spain

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