Daniel DeAngelo, MD, PhD, Chief, Division of Leukemia, Dana-Farber Cancer Institute, discusses treatment options available for systemic mastocytosis (SM).

SM is a rare, hematologic disorder most often caused by a mutation in the KIT D816V gene. The disorder is characterized by uncontrolled mast cell proliferation and activation across multiple organ systems, resulting in chronic, severe, and often unpredictable symptoms and extensive organ damage. A minority of SM patients have advanced SM, which encompasses a group of high-risk SM subtypes including aggressive systemic mastocytosis (ASM), systemic mastocytosis with an associated hematological neoplasm (SM-AHN), and mast cell leukemia (MCL).

As Dr. DeAngelo explains, treatment options are dependent on the subtype of SM. Currently, there are no FDA approved treatments for indolent and smouldering SM, the less severe forms of the disease. For patients with these forms, supportive care in the form of antihistamines, leukotriene inhibitors, and/or corticosteroids is common. For patients with advanced SM, a few treatment options are available. Chemotherapy may be used to suppress mast cell count. Certain interferons can also do this. Additionally, there are two FDA-approved drug therapies for advanced SM. The first is midostaurin, which is a multi-targeted protein kinase inhibitor that was approved for the treatment of advanced SM in 2018. The second, and most recent, is avapritinib, which is a kinase inhibitor approved for the treatment of advanced SM in June 2021.

To learn more about SM and other rare hematologic disorders, visit checkrare.com/diseases/hematologic-disorders/