Avapritinib is a targeted therapy, which means that it is designed to specifically target specific proteins or pathways involved in the growth and proliferation of cancer cells. In the case of avapritinib, it specifically targets the KIT protein, which is overexpressed in certain types of cancer cells and mast cells. It is approved for treating adult patients with unresectable or metastatic gastrointestinal stromal tumors (GISTs) that cannot be treated with other medications or returned after treatment.
It is also approved for treating adult patients with indolent or smoldering systemic mastocytosis, aggressive systemic mastocytosis, or mast cell leukemia. These rare disorders cause too many mast cells (a type of white blood cell) to build up in the body and can lead to various symptoms, including skin rash, abdominal pain, and difficulty breathing.