Indolent and smouldering systemic mastocytosis: lines of therapy

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5 standard-of-care settings across 3 lines and 1 biomarker subgroup. Rows come from the cancer page's standard of care; the grid places each on its line and subgroup.

Line	All comers
Screening, prevention and diagnosis	1
Special situations	1
Other settings	3

Screening, prevention and diagnosis

Subgroup	Setting	Approach	Products and trials	Guideline	Evidence
All comers	Diagnosis	Serum tryptase, KIT D816V testing in peripheral blood, bone marrow biopsy with flow cytometry, tryptase gene copy number, bone density scan and screening for B and C findings.	Histopathology & immunohistochemistryMultiparameter flow cytometry MRDKITDriver mutation	NCCN Guidelines: Systemic Mastocytosis	95

Special situations

Subgroup	Setting	Approach	Products and trials	Guideline	Evidence
All comers	Moderate to severe symptoms despite supportive care	Avapritinib 25 mg daily (PIONEER, approved 2023), avoided when platelets are below 50 x 10^9/L; cladribine or interferon alfa as older cytoreductive options.	Avapritinib(PIONEER) Study to Evaluate Efficacy and Safety of Avapritinib (BLU-285), A Selective KIT Mutation-targeted Tyrosine Kinase Inhibitor, Versus Placebo CladribineInterferon alfa-2a/2bSmall-molecule kinase inhibitors	NCCN Guidelines: Systemic Mastocytosis	97

Other settings

Subgroup	Setting	Approach	Products and trials	Guideline	Evidence
All comers	Symptom control	H1 and H2 antihistamines, cromoglicate, leukotriene antagonists, proton-pump inhibitors; omalizumab for recurrent anaphylaxis; adrenaline autoinjectors for all; venom immunotherapy after sting anaphylaxis; bisphosphonates for osteoporosis.	Electronic patient-reported outcome (ePRO) symptom monitoring	NCCN Guidelines: Systemic Mastocytosis	32
All comers	Trials	Elenestinib (HARBOR) and bezuclastinib (Summit) as more selective KIT D816V inhibitors.	Elenestinib(HARBOR) Study to Evaluate Efficacy and Safety of BLU-263 Versus Placebo in Patients With Indolent Systemic MastocytosisBezuclastinib(Summit) A Study to Evaluate the Efficacy and Safety of CGT9486 Versus Placebo in Patients With Indolent or Smoldering Systemic Mastocytosis	NCCN Guidelines: Systemic Mastocytosis	41
All comers	Monitoring	Tryptase, KIT allele burden and blood count yearly; bone density; marrow re-examination only if progression is suspected.	Liquid biopsy (ctDNA)Molecular response (MMR, MR4, treatment-free remission)	NCCN Guidelines: Systemic Mastocytosis	87

Lines and subgroups are parsed from the setting text of each standard-of-care row and can misclassify an unusual phrasing; the row’s own setting is always shown. Guideline chips reflect the NCCN category and ESMO-MCBS grade recorded on the cancer page, checked on its stated date. Not medical advice.