Indolent systemic mastocytosis
disease diseaseOn this page
Also known as indolent systemic mastocytosis (morphologic abnormality)ISM
Summary
Indolent systemic mastocytosis (MONDO:0020331) is a disease and 14 clinical trials. Top therapeutic interventions include avapritinib, sarilumab, and masitinib. A subtype of systemic mastocytosis — broader associated-gene and molecular evidence is on the parent page (see Disease family below).
At a glance
- Prevalence: 1-5 / 10 000 (Europe) [Orphanet-validated]
- Phenotypes (HPO): 21
- Clinical trials: 14
Clinical features
Epidemiology
Prevalence records
1 prevalence record(s), Orphanet:
| Type | Class | Value | Geography | Validation |
|---|---|---|---|---|
| Point prevalence | 1-5 / 10 000 | Europe | Validated |
Signs & symptoms
Clinical features (HPO)
21 HPO clinical features (Orphanet curated; top 21 by frequency):
| HPO ID | Term | Frequency |
|---|---|---|
| HP:0005561 | Abnormality of bone marrow cell morphology | Very frequent (80-99%) |
| HP:0011121 | Abnormal skin morphology | Very frequent (80-99%) |
| HP:0031408 | Increased proportion of CD25+ mast cells | Very frequent (80-99%) |
| HP:0100494 | Abnormal mast cell morphology | Very frequent (80-99%) |
| HP:0100495 | Mastocytosis | Very frequent (80-99%) |
| HP:0000939 | Osteoporosis | Frequent (30-79%) |
| HP:0000988 | Skin rash | Frequent (30-79%) |
| HP:0000989 | Pruritus | Frequent (30-79%) |
| HP:0001025 | Urticaria | Frequent (30-79%) |
| HP:0011354 | Generalized abnormality of skin | Frequent (30-79%) |
| HP:0012393 | Allergy | Frequent (30-79%) |
| HP:0025081 | Darier’s sign | Frequent (30-79%) |
| HP:0031284 | Flushing | Frequent (30-79%) |
| HP:0031901 | Increased serum mast cell beta-tryptase concentration | Frequent (30-79%) |
| HP:0032155 | Abdominal cramps | Frequent (30-79%) |
| HP:0040186 | Maculopapular exanthema | Frequent (30-79%) |
| HP:0100845 | Anaphylactic shock | Occasional (5-29%) |
| HP:0004377 | Hematological neoplasm | Excluded (0%) |
| HP:0001744 | Splenomegaly | Very rare (<1-4%) |
| HP:0002240 | Hepatomegaly | Very rare (<1-4%) |
| HP:0002716 | Lymphadenopathy | Very rare (<1-4%) |
Identifiers
Disease identifiers
| Field | Value |
|---|---|
| Canonical name | indolent systemic mastocytosis |
| Mondo ID | MONDO:0020331 |
| Orphanet | 98848 |
| DOID | DOID:4660 |
| ICD-11 | 353283231 |
| NCIT | C9286 |
| SNOMED CT | 70910003 |
| UMLS | C0272203 |
| MedGen | 82897 |
| GARD | 0019595 |
| MedDRA | 10056452 |
| Is cancer (heuristic) | no |
Also known as: indolent systemic mastocytosis (morphologic abnormality) · ISM · ism
Disease family
This is a subtype of systemic mastocytosis. Genetic, therapeutic, and trial evidence is largely curated at the broader-term level — see the parent page for the associated-gene cohort and molecular evidence.
Classification path: disease by etiologic mechanism › cancer or benign tumor › neoplastic disease or syndrome › neoplasm › hematopoietic and lymphoid system neoplasm › hematopoietic and lymphoid cell neoplasm › myeloid neoplasm › mast cell neoplasm › mastocytosis › systemic mastocytosis › indolent systemic mastocytosis
Related subtypes (4): extracutaneous mastocytoma, systemic mastocytosis with an associated clonal hematologic non-mast cell lineage disease, aggressive systemic mastocytosis, mast cell leukemia
Subtypes (2): Smouldering systemic mastocytosis, isolated bone marrow mastocytosis
Genetics & variants
GWAS landscape
No GWAS associations recorded — common-variant (GWAS) studies don’t cover this disease (typical for Mendelian / rare diseases). See the curated gene cohort and Mendelian overlap below.
Variant details and genetic-evidence tiers
No tiered GWAS variants or ClinVar records for this disease.
Genes & proteins
No associated-gene cohort resolved for this disease. Atlas builds the molecular and therapeutic sections — associated genes, protein families, druggability, pathways, interactions, and drug associations — by aggregating over a disease’s associated genes (resolved via GWAS / GenCC / ClinVar / CIViC), and none resolved here. This is expected for antibody-mediated, autoimmune, or otherwise non-gene-defined conditions; the curated evidence for this disease is its clinical features, GWAS susceptibility, and clinical trials (above).
Function
No pathway enrichment — requires an associated-gene cohort.
Therapeutics
No druggable-target or therapeutic data for this disease’s cohort.
Clinical trials & evidence
Clinical trials
Clinical trials: 14.
Phase distribution (across all retrieved trials)
| Phase | Trials |
|---|---|
| PHASE2 | 6 |
| Not specified | 4 |
| PHASE3 | 2 |
| PHASE2/PHASE3 | 1 |
| PHASE1 | 1 |
Top trials by phase / activity
| NCT | Phase | Status | Title |
|---|---|---|---|
| NCT04910685 | PHASE2/PHASE3 | RECRUITING | (HARBOR) Study to Evaluate Efficacy and Safety of BLU-263 Versus Placebo in Patients With Indolent Systemic Mastocytosis |
| NCT00814073 | PHASE3 | COMPLETED | Masitinib in Severe Indolent or Smoldering Systemic Mastocytosis |
| NCT04333108 | PHASE3 | UNKNOWN | Masitinib in Severe Indolent or Smoldering Systemic Mastocytosis Unresponsive to Optimal Symptomatic Treatment |
| NCT03731260 | PHASE2 | ACTIVE_NOT_RECRUITING | (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 |
| NCT04655118 | PHASE2 | RECRUITING | Study of TL-895 in Subjects With Myelofibrosis or Indolent Systemic Mastocytosis |
| NCT05186753 | PHASE2 | ACTIVE_NOT_RECRUITING | (Summit) A Study to Evaluate the Efficacy and Safety of CGT9486 Versus Placebo in Patients With Indolent or Smoldering Systemic Mastocytosis |
| NCT01920204 | PHASE2 | UNKNOWN | Midostaurin in Indolent Systemic Mastocytosis |
| NCT02478957 | PHASE2 | COMPLETED | Treatment of Indolent Systemic Mastocytosis With PA101 |
| NCT03770273 | PHASE2 | COMPLETED | Safety and Efficacy of Subcutaneous Sarilumab in Improving the Quality of Life in People With Indolent Systemic Mastocytosis |
| NCT02808793 | PHASE1 | COMPLETED | A Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of AK002 |
| NCT07255638 | Not specified | RECRUITING | A Non-Interventional Study in Participants With Indolent Systemic Mastocytosis (ISM) in Germany |
| NCT07264959 | Not specified | RECRUITING | An Observational Study in Participants With Indolent Systemic Mastocytosis (ISM) |
| NCT03632811 | Not specified | COMPLETED | Adaptation of the Questionnaire Regarding Patient’s Quality of Life With Mastocytosis in the French Language |
| NCT06210698 | Not specified | UNKNOWN | Angioedema Biomarker Research Study |
Drugs tested across these trials (top 30)
| Molecule | Max phase | Trials referencing |
|---|---|---|
| AVAPRITINIB | 4 | 2 |
| SARILUMAB | 4 | 1 |
| MASITINIB | 3 | 2 |
| LIRENTELIMAB | 3 | 1 |
| ELENESTINIB | 2 | 1 |
Related Atlas pages
- Drugs: Avapritinib, Sarilumab, Masitinib, Lirentelimab