Avapritinib for treating indolent systemic mastocytosis

Avapritinib is in clinical development for treating indolent systemic mastocytosis (ISM) in adult patients with moderate to severe symptoms inadequately controlled with standard therapy or best supportive care. ISM is the most common form of systemic mastocytosis, a rare condition caused by a certain type of immune cells (mast cells) releasing excessive amounts of histamine within the tissues of the body. The symptoms of ISM can vary, but usually includes hot flushes, heart palpitations, bone and muscle pain, mood changes or problems concentrating; some less common symptoms can include headaches, chest pain, feeling unwell and diarrhoea. Although the condition is often not considered life threatening, emerging data suggest that patients with ISM had an increased risk of death compared with the general population, and their symptoms can have a significant reduction in their quality of life, with limited options for managing their symptoms.