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Masitinib in Severe Indolent or Smoldering Systemic Mastocytosis Unresponsive to Optimal Symptomatic Treatment

Phase 3 Study to Compare Oral Masitinib to Placebo in Treatment of Patients With Smouldering or Indolent Severe Systemic Mastocytosis, Unresponsive to Optimal Symptomatic Treatment

Status
UNKNOWN
Phases
Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT04333108
Enrollment
140
Registered
2020-04-03
Start date
2020-07-01
Completion date
2025-06-30
Last updated
2023-05-06

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Indolent Systemic Mastocytosis

Keywords

Mastocytosis with handicap, Mastocytosis, Mast cell, Mast cell infiltration, Skin, Bone marrow, Pruritus, Flushes, c-kit, c-kit mutation, Wild Type, Mutation Asp-816-Val(D816V), Indolent systemic mastocytosis, smoldering systemic mastocytosis

Brief summary

The purpose of this study is to evaluate the efficacy and safety of oral masitinib versus placebo in the treatment of patients suffering from smouldering or indolent systemic mastocytosis with severe symptoms of mast cell mediator release, unresponsive to optimal symptomatic treatment.

Detailed description

Masitinib is a selective tyrosine kinase inhibitor that modulates mast cell activity via inhibition of c-Kit, Lyn and Fyn kinase signaling pathways. This is a multicenter, randomized, double-blind, placebo-controlled, 2-parallel-group, trial comparing oral masitinib versus placebo in the treatment of patients suffering from smouldering or indolent systemic mastocytosis with severe symptoms of mast cell mediator release (also referred to as handicaps), unresponsive to optimal symptomatic treatment. The treatment period is 24 weeks. Participants receive masitinib (3.0 mg/kg/day), given orally twice daily, with a dose escalation to 4.5 mg/kg/day after 4 weeks of treatment, followed by dose escalation to 6.0 mg/kg/day after 4 weeks of treatment. Each ascending dose titration is subjected to a safety control.

Interventions

DRUGMasitinib

Masitinib 6 mg/kg/day

OTHERPlacebo

Matching placebo

OTHERBest Supportive Care

Optimal concomitant symptomatic treatments. Includes: H1- and H2-antihistamines, proton pump inhibitors (PPI), sodium cromoglycate, antidepressants, leukotriene antagonists and corticosteroids.

Sponsors

AB Science
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
18 Years to 75 Years
Healthy volunteers
No

Inclusion criteria

1. Patient with one of the following documented mastocytosis subtypes (variants): Smouldering Systemic Mastocytosis, Indolent Systemic Mastocytosis 2. An excess of mast cells or a presence of abnormal mast cells in at least two organs (among skin, bone-marrow and GI Tract). 3. Patient with documented systemic mastocytosis and evaluable disease based upon histological criteria 4. Patient with documented treatment failure of his/her symptom(s) (within the past 2 years) with at least two of the symptomatic treatments used at optimized dose: Anti H1, Anti H2, Proton pump inhibitor, Antidepressants, Cromoglycate Sodium, Antileukotriene. 5. Patient with severe symptoms of mastocytosis over the 14-day run-in period including at least one among pruritus, flushes, and depression: pruritus score ≥ 9, number of flushes per week ≥ 8, Hamilton rating scale for depression (HAMD-17) score ≥ 19.

Exclusion criteria

1. Patient with one of the following mastocytosis: Cutaneous Mastocytosis, Systemic Mastocytosis with an Associated clonal Hematologic Non Mast cell lineage Disease (SM-AHNMD), Mast cell leukemia (MCL), Aggressive systemic mastocytosis (ASM) 2. Previous treatment with any Tyrosine Kinase Inhibitor 3. Treatment with any investigational agent within 8 weeks prior to screening.

Design outcomes

Primary

MeasureTime frameDescription
Cumulative response (3R75%)24 weeksCumulative response in at least one of three severe baseline symptoms of mast cell mediator release (pruritus, flushes, or depression). Response was defined as a 75% improvement from baseline for any of these three symptoms. Cumulative response was defined as the number of actual responses between weeks 8 and 24, divided by the total number of possible responses over the same treatment period (ie, with five scheduled visits, each patient had a maximum of five to 15 possible responses depending on the number of severe baseline symptoms).

Secondary

MeasureTime frameDescription
Cumulative response (4R75%)24 weeksCumulative response in at least one of four severe baseline symptoms of mast cell mediator release (pruritus, flushes, depression, or asthenia). Response is defined as a 75% improvement from baseline for any of these four symptoms. Cumulative response was defined as the number of actual responses between weeks 8 and 24, divided by the total number of possible responses over the same treatment period (ie, with five scheduled visits, each patient had a maximum of five to 20 possible responses depending on the number of severe baseline symptoms).
Cumulative response (2R75%)24 weeksCumulative response in at least one of two severe baseline symptoms of mast cell mediator release (pruritus or flushes). Response is defined as a 75% improvement from baseline for either of these two symptoms. Cumulative response is defined as the number of actual responses between weeks 8 and 24, divided by the total number of possible responses over the same treatment period (ie, with five scheduled visits, each patient had a maximum of five to 10 possible responses depending on the number of severe baseline symptoms).
Cumulative response24 weeksCumulative response on each of the individual handicaps. Response is defined as a 75% improvement from baseline for either of these two symptoms. Cumulative response is defined as the number of actual responses between weeks 8 and 24, divided by the total number of possible responses over the same treatment period.

Countries

France, Germany, Netherlands, Poland, Romania, Russia, Ukraine, United Kingdom

Contacts

Primary ContactClinical Study Coordinator
clinical@ab-science.com+33(0)147200014

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026