CStone's partner Blueprint Medicines recently announced that the U.S. Food and Drug Administration (FDA) has approved a new indication for the targeted anticancer drug Ayvakit (avapritinib) for the treatment of advanced systemic diseases. Adult patients with mastocytosis (SM), including: aggressive SM (ASM), SM with related hematological tumors (SM-AHN) and mast cell leukemia (MCL). This indication was approved through the priority review process. Previously, the FDA has granted Ayvakit Orphan Drug Designation (ODD) and Breakthrough Drug Designation (BTD) for the treatment of advanced SM. Ayvakit is the first precision therapy aimed at the main driving factors of SM disease. The approval of the drug on the market gives patients with advanced SM for the first time a targeted therapy. Ayvakit can potently and selectively inhibit the D816V mutation KIT, which is the central driving factor of SM disease.