Treatment of Systemic Mastocytosis in Mast Cell Leukemia with KIT D816V Mutation
Mast cell leukemia (MCL) with a confirmed KIT D816V mutation is a well-defined presentation of systemic mastocytosis that directly informs first-line treatment selection.
Clinical Scenario
This protocol applies to patients with systemic mastocytosis presenting as mast cell leukemia (MCL) carrying a KIT D816V (c-KIT gene) mutation. This molecular finding is the central driver of treatment choice.
Treatment Approach
First-line management in this setting involves targeted kinase inhibitor therapy directed at the KIT D816V mutation. The full protocol specifies the preferred agent and the criteria guiding selection between available options.
Treatment Goals
Clinical targets include reversion of disease-related organ damage and a marked decrease in bone marrow mast cell burden.
References
DOI: 10.1002/ajh.26962
- Avapritinib (BLU-285): received FDA approval for first-line treatment for adult patients with advanced SM, including those with ASM, SM-AMN and MCL in June 2021, based on data from EXPLORER (NCT02561988) and PATHFINDER (NCT03580655), two multicenter, single-arm, open-label clinical trials.
- Midostaurin is appropriate both as first-line treatment, particularly in MCL patients, as well as salvage treatment in patients progressing after interferon-α or cladribine therapy.
- Recent data with potent tyrosine kinase inhibitors (TKI) that selectively target mutant-KIT have shown reversion of organ damage with marked decrease in BM MC burden, as well as the potential for KITD816V molecular remissions, suggesting the possibility of disease modifying therapeutic effect in patients with advanced SM.