According to a story from PR Newswire, the Blueprint Medicines Corporation recently announced that latest results from a Phase 1 clinical trial of avapritinib as a treatment for advanced systemic mastocytosis. These results suggest that the therapy could be a useful therapy for patients with this rare disease. The drug was able to reduce meaningful clinical response in patients with various disease subtypes.
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.
Clinical Trial Data
The trial demonstrated an 83 percent overall response rate to avapritinib. 24 percent of patients attained a complete response. At 12 months, the duration of response had reached 76 percent. Patient reported symptoms also saw a mean reduction of 41 percent. These findings suggest that avapritinib is capable of producing a long lasting therapeutic effect for patients with systemic mastocytosis regardless of which subtype of disease the patient has.
In addition, the drug appears to be reasonably will tolerated; 78 percent of patients were using the drug by the data cutoff day, and only four percent had to cease receiving the treatment because of adverse events. The data from this Phase 1 trial is definitely encouraging, and avapritinib is in the midst of ongoing testing in a Phase 2 clinical trial of patients with advanced systemic mastocytosis as well, which is currently dosing patients. Blueprint also plans to initiate an additional Phase 2 trial of patients with indolent or smoldering disease by the end of the year.
