Rationale: Patients with indolent or smoldering systemic mastocytosis can have severe
disabling symptoms. Almost all patients have fatigue, a compromised quality of life,
hampering normal functioning. Because this form of mastocytosis is not considered
life-threatening, mast cell eradication has never been applied and patients receive only
symptomatic therapy with histamine blockers. Midostaurin, a c-KIT inhibitor has shown
activity regarding symptom control and decrease of malignant mast cells in patients with
aggressive systemic mastocytosis (ASM) or mast cell leukemia