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Clinical Trial ● Currently Recruiting Phase II NCT04910685

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

(HARBOR) Study to Evaluate Efficacy and Safety of BLU-263 Versus Placebo in Patients With Indolent Systemic Mastocytosis — Recruiting • Phase II • Oncology • NCT04910685.

📅 06 Apr 2026 ⏱ 2 min read
Currently Recruiting
This trial is actively seeking participants in the UK. Discuss eligibility with your patient before referring.
Status
Currently Recruiting
Phase
Phase II
NCT ID
NCT04910685
Sponsor
Blueprint Medicines Corporation
Start
2021-11-30
ClinicaliQ Trial Snapshot
  • (HARBOR) Study to Evaluate Efficacy and Safety of BLU-263 Versus Placebo in Patients With Indolent Systemic Mastocytosis — Recruiting • Phase II • Oncology • NCT04910685.
  • 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….
  • Sponsor: Blueprint Medicines Corporation.

Verify eligibility, endpoints and current status on the original source registry before acting on this summary.

Use This Page For
  • Quick orientation before opening the registry record.
  • Checking recruitment status, phase and sponsor at a glance.
  • Connecting this trial to nearby guidelines, Drug Science and education.
What This Trial Is Studying

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…

Eligibility Snapshot
  • Key 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

Use the source registry for the full inclusion and exclusion criteria before discussing referral or enrolment.

Full Trial Details
View this trial on the source registry
Eligibility criteria, protocol, and results when available
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