A Phase 2 interventional study of Avapritinib and Placebo in Indolent Systemic Mastocytosis, sponsored by Blueprint Medicines Corporation. Active, not recruiting at 49 sites in 13 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-02.
Sponsored by Blueprint Medicines Corporation (part of Sanofi) · Phase 2, Interventional, and Treatment
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Among 10 studies in Mastocytosis, Systemic by Sanofi — 4 open to participants now, 5 under way, 1 of them phase 3. Mastocytosis, Systemic · Sanofi.
Among the 10 studies in Mastocytosis, Systemic by Sanofi, this one is the only one that started in 2019, is one of 2 in phase 2, and was the 4th registered.
56 studies on the registry are indexed under Mastocytosis, Systemic; 16 are open to participants now.
Browse Mastocytosis, Systemic studies →4 of the 10 studies in Mastocytosis, Systemic by Sanofi are open now, in 12 countries. Recruiting first, the newest first:
Blueprint Medicines Corporation · Sites in United States
Ages 18+
Blueprint Medicines Corporation · Sites in Germany
Ages 18+
Blueprint Medicines Corporation · Sites in Belgium, Canada, France and 6 more countries
Blueprint Medicines Corporation · Sites in United States, Argentina, Australia and 22 more countries
Ages 18+
By country, each count listing its studies:
Of the 14 Mastocytosis, Systemic studies recruiting now, 12 (86%) set no upper age limit and 2 (14%) stop at 75 or younger; 4 take children under 18; 1 takes healthy volunteers.
This study: 18 Years and older · all sexes · no healthy volunteers.
The full table on the hub →This tab as a report to print or save as PDF → With an account.
10 studies; the count open now beside each. This study's row is marked.
A study in two phases is counted once above. Listed by phase, each with its combined phases: Phase 1 2 · Phase 2 3 · Phase 3 1 · Phase 4 1
First in 2015; this study’s year is marked. 1 started in 2019.
By drug class, each counting the studies that test any of its medicines:
This study's enrollment of 251 is above the median of 36 across 34 interventional studies indexed under Mastocytosis, Systemic.
Median enrollment 97 across the 6 interventional studies, 234 across the 4 observational. Of the 5 that completed or were terminated, 1 (20%) have results posted.
This tab as a report to print or save as PDF → With an account.
This study is registered under Blueprint Medicines Corporation, one of the names counted as Sanofi. Under that name alone:
Blueprint Medicines Corporation is the lead sponsor of 32 studies on the registry; 6 are open to participants now.
Of its 14 completed or terminated interventional studies of FDA-regulated products, 3 (21%) have results posted.
1 of the studies in Mastocytosis, Systemic by Sanofi that are under way reach primary completion within a year, 0 of them phase 3. Phase 3 first, then by date:
| Study | Primary completion |
|---|---|
| NCT03731260Blueprint Medicines Corporation(PIONEER) Study to Evaluate Efficacy and Safety of Avapritinib (BLU-285), A Selective KIT Mutation-targeted Tyrosine Kinase Inhibitor, Versus Placebo in Patients With Indolent Systemic Mastocytosis | 2027-06-23 |
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Among the 10 studies in Mastocytosis, Systemic by Sanofi, from their registry updates:
Nothing recorded among them since 2026-09-25.
This tab as a report to print or save as PDF → With an account.
This is a Phase 2, randomized, double-blind, placebo-controlled study comparing the efficacy and safety of avapritinib + best supportive care (BSC) with placebo + BSC in patients with indolent systemic mastocytosis (ISM) whose symptoms are not adequately controlled by BSC. The study will be conducted in 3 parts. All patients will receive treatment with avapritinib during Part 3 including those rolling over from the placebo group.
Key Inclusion Criteria:
Key Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.
The study may name a correction formula and a limit in milliseconds, often around 450–480.
Biopsy and archival tissue
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ECOG performance status
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
QT and QTc
On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.
The study may name a correction formula and a limit in milliseconds, often around 450–480.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Avapritinib will be administered orally in continuous 28-day cycles
Drug: Avapritinib
Avapritinib will be administered orally in continuous 28-day cycles
Drug: Avapritinib
Avapritinib will be administered orally in continuous 28-day cycles
Drug: Avapritinib
Placebo will be administered orally in continuous 28-day cycles
Drug: Placebo
Avapritinib will be administered orally in continuous 28-day cycles
Drug: Avapritinib
Placebo will be administered orally in continuous 28-day cycles
Drug: Placebo
Avapritinib will be administered orally in continuous 28-day cycles
Drug: Avapritinib
Avapritinib tablet
Also known as: BLU-285
Placebo tablet
Part 1: Recommended Phase 2 dose (RP2D) in patients with ISM
Time frame: 9 months
Part 2: Mean change in ISM Symptom Assessment Form (ISM-SAF) total symptom score (TSS) as compared to placebo
0 - 110 points (higher value represents worse symptom outcomes)
Time frame: 6 months
Part 3: Number of Participants with Adverse Events
Time frame: Up to 5 years
Part 2: Proportion of patients with a ≥50% reduction in serum tryptase
Time frame: 6 months
Part 2: Proportion of patients with a ≥50% reduction in peripheral blood V-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene homolog aspartate 816 valine (KIT D816V) allele fraction or undetectable for patients with detectable mutation at Baseline
Time frame: 6 months
Part 2: Proportion of patients with ≥50% reduction in ISM-SAF TSS
Time frame: 6 months
Part 2: Proportion of patients with ≥30% reduction in ISM-SAF TSS
Time frame: 6 months
Part 2: Proportion of patients with a ≥50% reduction in bone marrow mast cells or no aggregates for patients with aggregates at Baseline
Time frame: 6 months
Parts 1, 2, and 3: Change in serum tryptase
Time frame: Up to 5 years
Parts 1, 2, and 3: Change in KIT D816V allele burden in blood
Time frame: Up to 5 years
Parts 1, 2, and 3: Change in bone marrow mast cells
Time frame: Up to 5 years
Parts 1, 2, and 3: Change in best supportive care (BSC) concomitant medication usage
Time frame: Up to 5 years
Parts 1, 2, and 3: Change from Baseline in ISM-SAF Score
Time frame: Up to 5 years
Parts 1, 2, and 3: Change in Mastocytosis Quality of Life Questionnaire (MC-QoL)
Time frame: Up to 5 years
Parts 1, 2, and 3: Change in Patient's Global Impression of Symptom Severity (PGIS)
Time frame: Up to 5 years
Parts 1, 2, and 3: Change in 12-item Short Form Health Survey (SF-12)
0 - 100 points (higher value represents better symptom outcomes)
Time frame: Up to 5 years
Parts 1, 2, and 3: Change in Patients' Global Impression of Change (PGIC)
1 - 7 (higher value represents worse symptom outcomes)
Time frame: Up to 5 years
Parts 1, 2, and 3: Change in EuroQuol 5 Dimensions 5 Levels (EQ 5D-5L)
0 - 100 (higher value represents better symptom outcomes)
Time frame: Up to 5 years
Parts 1, 2, and 3: Safety of avapritinib as assessed by number of adverse events
CTCAE version 5.0
Time frame: Up to 5 years
Started Apr 2019 (actual). Primary completion is estimated for Jun 2027, 98 months after the start.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is active, not recruiting, as verified in Sep 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Avapritinib
Blueprint Medicines Corporation →