A 100-mg dose of bezuclastinib was safe and effective in improving symptoms and biomarkers for mast cell burden in non-advanced systemic mastocytosis patients, according to findings from the phase 2 Summit trial's open-label extension, presented at the 2024 ASH Annual Meeting. Bezuclastinib demonstrated rapid, deep, and sustained reductions in serum tryptase and significant improvements in symptom severity and quality of life over 24 weeks.