Avapritinib (Ayvakit) is a drug that specifically blocks the KIT protein and is approved for the treatment of indolent systemic mastocytosis (ISM)[1]. In the PIONEER clinical trial, which was the largest trial ever conducted in ISM, avapritinib showed statistically significant and sustained clinical benefits in all measured ISM symptoms compared to placebo[1]. The drug led to approximately a 30% average reduction in symptoms by week 16 and improved patients' quality of life[4]. Avapritinib was well tolerated with a favorable safety profile, with most adverse events being mild (grade 1), the most common being hematuria, edema, increased alkaline phosphatase, and insomnia[1]. Indolent systemic mastocytosis affects approximately 40,000 people in the European Union and is characterized by chronic, severe and often unpredictable symptoms including anaphylaxis, rash, pruritus, diarrhoea, brain fog, fatigue and bone pain[1]. Avapritinib is the first and only drug approved for the treatment of ISM that is specifically designed to target the primary genetic factor causing the disease[1].