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(HARBOR) Study to Evaluate Efficacy and Safety of BLU-263 Versus Placebo in Patients With Indolent Systemic Mastocytosis

Phase 2
Recruiting
Conditions
Indolent Systemic Mastocytosis
Smoldering Systemic Mastocytosis
Interventions
Drug: Placebo
Registration Number
NCT04910685
Lead Sponsor
Blueprint Medicines Corporation
Brief Summary

This is a randomized, double-blind, placebo-controlled, Phase 2/3 study comparing the efficacy and safety of elenestinib (BLU-263) + symptom directed therapy (SDT) with placebo + SDT in participants with indolent systemic mastocytosis (ISM) whose symptoms are not adequately controlled by SDT. Parts 1 and 2 will enroll participants with ISM. Participants enrolled in Part 2 will roll over onto Part 3 to receive treatment with elenestinib in an open-label fashion following completion of the earlier Part. Part K will enroll participants with ISM who have previously received an approved selective KIT inhibitor. The study also includes pharmacokinetic (PK) groups that will enroll participants with ISM.

Detailed Description

Not available

Recruitment & Eligibility

Status
RECRUITING
Sex
All
Target Recruitment
534
Inclusion Criteria

All Participants:

-Participant must have an Eastern Cooperative Oncology Group Performance Status (ECOG PS) of 0 to 2.

Part 1 and PK groups:

  • Participant has confirmed diagnosis of ISM, confirmed by Central Pathology Review
  • Participant must have failed to achieve adequate symptom control for 1 or more Baseline symptoms, as determined by the Investigator, with at least 2 of the following symptom-directed therapies administered: H1 blockers, H2 blockers, proton-pump inhibitors, leukotriene inhibitors, cromolyn sodium, corticosteroids, or omalizumab.
  • Participants must have SDT for ISM symptom management stabilized for at least 14 days prior to starting screening procedures.
  • For participants receiving corticosteroids, the dose must be ≤ 20 mg/day prednisone or equivalent, and the dose must be stable for ≥ 14 days.

Part K:

-Participant has confirmed diagnosis of ISM, confirmed by Central Pathology Review

Part S:

-Participant has confirmed diagnosis of SSM, confirmed by Central Pathology Review of BM biopsy and central review of B- and C-findings by WHO diagnostic criteria.

Part 2:

-Participant has confirmed diagnosis of ISM, confirmed by Central Pathology Review

Key

Exclusion Criteria
  • Participant has been diagnosed with any of the following WHO systemic mastocytosis (SM) sub-classifications: cutaneous mastocytosis only, SM with an associated hematologic neoplasm of non-MC lineage (SM-AHN), aggressive SM, mast cell leukemia, or mast cell sarcoma.
  • Participant has been diagnosed with another myeloproliferative disorder.
  • Participant has organ damage attributable to SM.
  • Participant has clinically significant, uncontrolled, cardiovascular disease
  • Participant has a QT interval corrected using Fridericia's formula (QTcF) > > 470 milliseconds (msec) (for females) or > 450 msec (for males).
  • Participant has a history of a primary malignancy that has been diagnosed or required therapy within 3 years. The following prior malignancies are not exclusionary: completely resected basal cell and squamous cell skin cancer, curatively treated localized prostate cancer, and completely resected carcinoma in situ of any site.
  • Time since any cytoreductive therapy including masitinib and midostaurin should be at least 5 half-lives or 14 days (whichever is longer), and for cladribine, interferon alpha, pegylated interferon, or antibody therapy < 28 days or 5 half-lives of the drug (whichever is longer), before beginning the screening period.
  • Participant has received radiotherapy or psoralen and ultraviolet A (PUVA) therapy < 14 days before beginning the screening period.

Other protocol-defined criteria apply.

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
(Part 1) Elenestinib Dose 1 + SDTElenestinibParticipants will receive SDT and elenestinib. SDT will be determined on a per participant basis. Elenestinib will be administered orally, once daily until completion of Part 1.
(Part 1) Elenestinib Dose 2 + SDTElenestinibParticipants will receive SDT and elenestinib. SDT will be determined on a per participant basis. Elenestinib will be administered orally, once daily until completion of Part 1.
(Part 1) Elenestinib Dose 3 + SDTElenestinibParticipants will receive SDT and elenestinib. SDT will be determined on a per participant basis. Elenestinib will be administered orally, once daily until completion of Part 1.
(Part 1) Placebo + SDTPlaceboParticipants will receive SDT and matching placebo. SDT will be determined on a per participant basis. Placebo will be administered orally, once daily until completion of Part 1.
(Part 2) Elenestinib Dose 1 + SDTElenestinibParticipants will receive SDT and elenestinib. SDT will be determined on a per participant basis. Elenestinib will be administered orally, once daily for approximately 48 weeks.
(Part 2) Placebo + SDTPlaceboParticipants will receive SDT and matching placebo. SDT will be determined on a per participant basis. Placebo will be administered orally, once daily for approximately 48 weeks.
(Part 3) Elenestinib + SDTElenestinibParticipants will receive SDT and elenestinib. SDT will be determined on a per participant basis. Elenestinib will be administered orally, once daily for up to approximately 5 years.
(Part S) Elenestinib Dose 1 + SDTElenestinibParticipants will receive SDT and elenestinib. SDT will be determined on a per participant basis. Elenestinib will be administered orally, once daily for up to approximately 5 years.
(Part K) Elenestinib Dose 1 + SDTElenestinibParticipants will receive SDT and elenestinib. SDT will be determined on a per participant basis. Elenestinib will be administered orally, once daily for up to approximately 5 years.
(PK groups) Elenestinib + SDTElenestinibParticipants will receive SDT and elenestinib. SDT will be determined on a per participant basis. Elenestinib will be administered orally, once daily for up to approximately 5 years.
Primary Outcome Measures
NameTimeMethod
Part 1: Number of participants with Treatment-emergent Adverse Events (TEAEs)Up to 12 weeks
Part 1: Mean change from baseline in ISM-Symptom in Assessment Form (ISM-SAF) Total Symptom Score (TSS)Baseline, Week 13
Part 2: Mean change from baseline in ISM-SAF TSSBaseline, Week 49
Part 3: Number of participants with Adverse Events (AEs)Up to 5 years
Part 3: Change from baseline in ISM-SAF TSSBaseline up to 5 years
Secondary Outcome Measures
NameTimeMethod
Part 1: Change from baseline in serum tryptaseBaseline, Week 13
Part 1: Change from baseline in KIT D816V allele fraction in bloodBaseline, Week 13
Part 1: Change from baseline in Bone Marrow (BM) mast cellsBaseline, Week 13
Part 1: Mean change from baseline in ISM-SAF individual symptom scoresBaseline, Week 13
Part 1: Time to achieve 30% reduction from baseline in ISM-SAF TSSBaseline up to Week 13
Part 1: Time to achieve 30% reduction from baseline in ISM-SAF domain scoresBaseline up to Week 13
Part 2: Proportion of participants achieving normalized tryptaseBaseline up to Week 49
Part 2: Proportion of participants who achieve an undetectable level or at least a 50% reduction in KIT D816V Variant Allele Frequency (VAF)Baseline up to Week 49
Part 2: Proportion of participants achieving symptom control as defined by achieving mild symptomsBaseline up to Week 49
Part 2: Mean percent change from baseline in Bone Mineral Density (BMD)Baseline, Week 49
Part 2: Mean change from baseline in the annualized rate of anaphylaxis eventsBaseline, Weeks 25 to 48
Part 2: Mean change from baseline in Quality of Life (QoL) scoresBaseline, Week 49
Part 2: Mean change from baseline in ISM-SAF domain scoresBaseline, Week 49
Part 2: Number of participants with AEsUp to Week 49
Part 2: Proportion of participants with a 50% reduction in ISM-SAF TSSBaseline, Weeks 24 and 48
Part 2: Proportion of participants with a 50% reduction in ISM-SAF domain scoresBaseline, Weeks 24 and 48
Part 2: Proportion of participants with a 30% reduction in ISM-SAF TSSBaseline, Weeks 24 and 48
Part 2: Proportion of participants with a 30% reduction in ISM-SAF domain scoresBaseline, Weeks 24 and 48
Part 3: Proportion of participants achieving symptom control as defined by achieving mild symptomsBaseline up to 5 years
Part 3: Change from baseline in ISM-SAF domain scoresBaseline, up to 5 years
Part 3: Proportion of participants achieving a normalized tryptaseBaseline up to 5 years
Part 3: Change from baseline in BMDBaseline up to 5 years
Part 3: Change from baseline in the annualized rate of anaphylaxis eventsBaseline up to 5 years
Parts 2 and 3: Change from baseline in serum tryptaseBaseline up to 5 years
Parts 2 and 3: Change from baseline in KIT D816V allele fraction in bloodBaseline up to 5 years
Parts 2 and 3: Change from baseline in Bone Marrow (BM) mast cellsBaseline up to 5 years
Parts 2 and 3: Proportion of participants achieving controlled diseaseBaseline up to 5 years
Parts 2 and 3: Change from baseline in skin lesions as assessed by the fractional body surface area of the most affected skin areaBaseline up to 5 years
Parts 2 and 3: Change from baseline in the number of concomitant medications identified as SDTBaseline up to 5 years
Parts 2 and 3: Change from baseline in ISM-SAF Individual Symptom ScoresBaseline up to 5 years
Parts 2 and 3: Change from baseline in ISM-SAF Lead (most severe) Symptom ScoreBaseline up to 5 years
Parts 2 and 3: Change from baseline in QoL scoresBaseline up to 5 years
Part S: Number of participants with AEsBaseline up to 5 years
Part S: Proportion of participants who achieve a Pure Pathologic Response (PPR)Baseline up to 5 years
Part S: Mean change from baseline in ISM-SAFBaseline, Week 25
Part K: Number of participants with AEsBaseline up to 5 years
Part K: Change from baseline in serum tryptaseBaseline up to 5 years
Part K: Change from baseline in KIT D816V allele fraction in bloodBaseline up to 5 years
Part K: Mean change from baseline in ISM-SAF TSSBaseline up to 5 years
Part K: Change from baseline in QoL scoresBaseline up to 5 years

Trial Locations

Locations (52)

Hospital Universitario Ramon y Cajal

🇪🇸

Madrid, Spain

Hospital Virgen del Valle - Instituto de Estudios de Mastocitosis de Castilla-La Mancha

🇪🇸

Toledo, Spain

Uppsala University Hospital

🇸🇪

Uppsala, Sweden

University Hospital Basel

🇨🇭

Basel, Switzerland

University of Alabama at Birmingham

🇺🇸

Birmingham, Alabama, United States

Stanford Cancer Institute

🇺🇸

Palo Alto, California, United States

Brigham and Women's Hospital

🇺🇸

Boston, Massachusetts, United States

Michigan Medicine University of Michigan

🇺🇸

Ann Arbor, Michigan, United States

Mayo Clinic

🇺🇸

Rochester, Minnesota, United States

Roswell Park Cancer Institute

🇺🇸

Buffalo, New York, United States

Columbia University Medical Center

🇺🇸

New York, New York, United States

University of Cincinnati Medical Center

🇺🇸

Cincinnati, Ohio, United States

The University of Texas, MD Anderson Cancer Center

🇺🇸

Houston, Texas, United States

Huntsman Cancer Institute, University of Utah

🇺🇸

Salt Lake City, Utah, United States

Princess Alexandra Hospital

🇦🇺

Woolloongabba, Queensland, Australia

The Alfred Hospital

🇦🇺

Melbourne, Victoria, Australia

Kepler Universitatsklinikum, Med Campus III. Clinic of Internal Medicine 3 - Hematology and Oncology

🇦🇹

Linz, Austria

Unitversitair Ziekenhuis Antwerpen

🇧🇪

Edegem, Antwerpen, Belgium

CHU Amiens-Picardie

🇫🇷

Amiens, France

CHU de Caen

🇫🇷

Caen, France

CHU Grenoble

🇫🇷

Grenoble Cedex 9, France

CHU de Limoges

🇫🇷

Limoges Cedex, France

CHU de Nantes

🇫🇷

Nantes, France

Hôpital de la Pitié Salpétrière

🇫🇷

Paris, France

Hôpital Necker - Départementd 'HématologieA dultes

🇫🇷

Paris, France

CHU de Poitiers

🇫🇷

Poitiers, France

CHU Toulouse - Hopital Larrey

🇫🇷

Toulouse, France

Universitätsklinikum RWTH Aachen Klinik für Hämatologie, Onkologie, Hämostaseologie und Stammzelltransplantation

🇩🇪

Aachen, Germany

Charité - Universitätsmedizin Berlin Institute of Allergology

🇩🇪

Berlin, Germany

University Clinic Erlangen

🇩🇪

Erlangen, Germany

University Clinic Hamburg Eppendorf

🇩🇪

Hamburg, Germany

Universitätsmedizin Mannheim III. Medizinische Klinik Universität Heidelberg Medizinische Fakultät Mannheim

🇩🇪

Mannheim, Germany

LMU Klinikum

🇩🇪

Munich, Germany

Dipartimentod i Oncoematologia Istituto Scientifico Romagnolop er lo studio e la cura dei tumori (IRST)- IRCCS

🇮🇹

Meldola, Forli-Cesena, Italy

UOC Ematologia

🇮🇹

Milano, Lombardia, Italy

SOD Ematologia (Ambulatori)- AOUC Azienda Ospedaliero Universitaria Careggi

🇮🇹

Firenze, Toscana, Italy

Unita Operativa di Ematologia AOU Policlinico S. Orsola-Malpighi

🇮🇹

Bologna, Italy

S.C. Ematologia Fondazione I.R.C.C.S. Policlinico San Matteo

🇮🇹

Pavia, Italy

S.S.D. Immunologia Clinica e Allergologia Azienda Ospedaliera Universitaria San Giovanni di Dio e Ruggi d'Aragona

🇮🇹

Salerno, Italy

Unità Operativa di Allergologia Azienda Ospedaliera Universitaria Integrata di Verona

🇮🇹

Verona, Italy

ErasmusMC

🇳🇱

Rotterdam, Zuid-Holland, Netherlands

University Medical Center Groningen

🇳🇱

Groningen, Netherlands

Oslo University Hospital

🇳🇴

Oslo, Norway

Centro Hospitalar de Lisboa Central, E.P.E. - Hospital de Santo Antonio dos Capuchos

🇵🇹

Lisbon, Portugal

CHUPorto, EPE - Hospital de Santo António

🇵🇹

Porto, Portugal

Centro Hospitalar Universitario Sao Joao, E.P.E.

🇵🇹

Porto, Portugal

Hospital Universitario Vall d'Hebron

🇪🇸

Barcelona, Spain

Luzerner Kantonsspital

🇨🇭

Luzern, Switzerland

University Hospital of Wales

🇬🇧

Cardiff, United Kingdom

Guy's and St Thomas's NHS Foundation Trust

🇬🇧

London, United Kingdom

Cancer and Haematology Centre

🇬🇧

Oxford, United Kingdom

University Hospital Plymouth NHS Trust

🇬🇧

Plymouth, United Kingdom

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