The use of midostaurin in the treatment of advanced systemic mastocytosis

Abstract

Systemic mastocytosis (SM) is a rare myeloproliferative neoplasms (MPN) characterized by clonal growth and accumulation of mast cells in various organs, mainly in the skin, bone marrow, liver, spleen, and lymph nodes. In its advanced form, SM leads to impairment of their function. The clinical course is highly variable, ranging from slow to very aggressive with progressive multi-organ failure and a significant risk of leukemic transformation. Advanced SM is an indication for cytoreductive therapy. So far, various treatment strategies have been used, including cladribine (2-CDA), imatinib, interferon alpha (IFN-α), as well as classic cytostatics (hydroxycarbamide, cytarabine or fludarabine). However, none of the options mentioned provided satisfactory response rates. Currently, high hopes are related to midostaurin — a multi-pathway tyrosine kinase inhibitor The drug was approved for the treatment of advanced forms of SM by the US Food and Drug Administration (FDA) in April 2017 based on the satisfactory results of phase II clinical trial #CPKC412D2201. In this paper, we present case reports of two patients diagnosed with aggressive systemic mastocytosis (ASM) and systemic mastocytosis with an associated hematologic neoplasm (SM-AHN) treated with midostaurin as part of the early access program.