According to a story from mdmag.com, a phase 2 trial testing the drug avapritinib as a treatment for systemic mastocytosis is currently ongoing. The results so far suggest that the medication could provide a meaningful benefit for patients. At this juncture, there are no FDA approved disease modifying treatments for this rare disease. Current treatment approaches often fail to provide quality of life improvements, with most patients experiencing long term symptoms and morbidity.
About Systemic Mastocytosis
Systemic mastocytosis is a rare disorder that affects mast cells, or mastocytes. The disease is most characterized by the abnormal accumulation of defective mast cells and mast cell precursors. In most cases, the disorder is linked to a mutation which affects the c-kit, or cell surface receptor, that mast cells express. In systemic mastocytosis, mast cells appear in the bone marrow and in other internal organs where these cells are not normally present, inhibiting their function. Symptoms include enlarged spleen and liver, fatigue, skin lesions, malabsorption, abdominal pain, peptic ulcers, diarrhea and vomiting, eye discomfort, inflammation of the ear, nose, and throat, anaphylactic shock, depression, headache, low blood pressure, and bone pain. While there is no cure for the disease, treatment options may include corticosteroids, proton pump inhibitors, antidepressants, antihistamines, and cytoreductive therapy. Most patients have normal life expectancy, but severe cases are potentially fatal. To learn more about systemic mastocytosis, click here.
Avapritinib was approved last January for the treatment of gastrointestinal stromal tumor that carries a certain mutation. As it just so happens, this mutation, known as KIT D816V, is also linked to systemic mastocytosis. The patients in the study have been treated with the drug for 16 weeks and patients across all dosing cohorts (25, 50, and 100 mg) reported symptoms scores that were around 30 percent lower.
The benefit seems to improve over time and impacted a broad array of symptoms affecting the skin, neurocognition, and gastrointestinal system. While the trial hasn’t completed yet, the results so far certainly bode well for patients that are dealing with systemic mastocytosis. Avapritinib has the potential to alter the treatment landscape for this rare illness.