Blueprint Medicines Highlights Leading Portfolio of Mast Cell-Targeted Therapies at 2025 AAAAI / WAO Joint Congress

Core Insights - Blueprint Medicines Corporation presented data on AYVAKIT® (avapritinib) demonstrating its long-term safety and efficacy for treating indolent systemic mastocytosis (ISM), with sustained symptom relief and quality-of-life improvements over multiple years of therapy [1][2] - AYVAKIT-treated patients showed significant improvements in bone health, emphasizing the importance of early treatment in ISM [1][5] - The company reported positive results from the Phase 1 trial of BLU-808, an oral wild-type KIT inhibitor, indicating a wide therapeutic window for mast cell activity modulation [1][7] AYVAKIT Efficacy and Safety - AYVAKIT 25 mg once daily was well-tolerated over a median of 3 years, with no new safety signals identified; common treatment-related adverse events included low-grade peripheral edema, periorbital edema, headache, and nausea [5] - Patients experienced durable improvements in overall symptoms and quality of life, with 93% of patients showing improved or stable benefits after escalating to AYVAKIT 50 mg QD [5] - Real-world data indicated that 67% of ISM patients had osteoporosis/osteopenia, compared to 34% in a matched control cohort (p<0.0001) [5] BLU-808 Development - BLU-808 demonstrated a favorable safety profile in healthy volunteers, with no serious adverse events or dose modifications required [10] - The investigational drug achieved over 80% reductions in serum tryptase levels, indicating effective mast cell target engagement [10] - The company plans to initiate multiple proof-of-concept trials for BLU-808, with initial data expected later in 2025 [2] Industry Context - Systemic mastocytosis (SM) is a rare disease primarily driven by the KIT D816V mutation, affecting approximately 95% of cases, leading to severe and unpredictable symptoms that significantly impact patients' quality of life [9][11] - AYVAKIT is currently approved for treating ISM and advanced SM, marking a significant advancement in therapeutic options for these patients [13]