Nature Medicine publishes results from two registration studies of Ayvakit.

The publications feature overall response, patient-reported outcomes and survival data, which reinforce the durable activity of Ayvakit. Additional new analyses underscore the treatment's impact regardless of patient subgroup or disease pathology. Based on these data, Ayvakit was approved by the FDA for the treatment of adults with advanced SM in June 2021.

In addition, Blueprint Medicines announced plans to report four SM data presentations, including an oral presentation on the EXPLORER trial, at the 63rd American Society of Hematology (ASH) Annual Meeting and Exposition in Atlanta on December 11-14, 2021.

Nature Medicine Publication Highlights,:Across the EXPLORER and PATHFINDER studies, 148 patients with advanced SM were enrolled as of the data cutoff dates. Treatment response was evaluated using modified IWG-MRT-ECNM criteria, with the overall response rate defined as complete remission with full or partial recovery of peripheral blood counts, partial remission or clinical improvement. All responses were confirmed. The results were reported as of a data cutoff date of May 27, 2020 for the EXPLORER trial and June 23, 2020 for the PATHFINDER trial. i. Across both studies, statistically significant improvements in patient-Ayvakit showed broad activity across all advanced SM subtypes, including SM with an associated hematological neoplasm (SM-AHN). For example, substantial reductions were observed in monocytosis in patients with SM and chronic myelomonocytic leukemia, and in eosinophilia in patients with SM and chronic eosinophilic leukemia, potentially reflecting the multi-lineage involvement of the KIT D816V mutation.

Ayvakit was generally well-tolerated, and most adverse events (AEs) were Grade 1 or 2. The most common AEs included edema, thrombocytopenia, anemia, diarrhea, nausea, fatigue, vomiting, neutropenia, headache, cognitive effects and abdominal pain. Overall, 10 percent of patients in the EXPLORER trial and 5 percent of patients in the PATHFINDER trial discontinued Ayvakit due to treatment-related AEs. Ayvakit is not recommended for the treatment of patients with advanced SM with low platelet counts (less than 50,000/µL), which is consistent with current patient eligibility criteria in the EXPLORER and PATHFINDER trials.

See- Published: 06 December 2021; "Safety and efficacy of avapritinib in advanced systemic mastocytosis: the phase 1 EXPLORER trial"-Daniel J. DeAngelo, Deepti H. Radia, Tracy I. George, William A. Robinson, et al., -Nat Med (2021). https://doi.org/10.1038/s41591-021-01538-9.

Published: 06 December 2021: "Efficacy and safety of avapritinib in advanced systemic mastocytosis: interim analysis of the phase II PATHFINDER trial"-Jason Gotlib, Andreas Reiter, Deepti H. Radia, Michael W. Deininger, et al,., . Nat Med (2021). https://doi.org/10.1038/s41591-021-01539-8.