[Avapritinib for systemic mastocytosis with an associated myelodysplastic/myeloproliferative neoplasm: a case report and literature review].

Systemic mastocytosis (SM) with an associated myelodysplastic/myeloproliferative neoplasm (MDS/MPN) is a rare subtype of myeloid neoplasms. Avapritinib, a potent and selective inhibitor of KIT D816V, is approved for treating advanced systemic mastocytosis (AdvSM). We report a case of a patient with SM and an associated MDS/MPN treated with avapritinib. The patient achieved sustained complete remission (CR) of SM, with persistent molecular negativity for the KIT D816V mutation, but ultimately succumbed to disease progression to chronic myelomonocytic leukemia (CMML). Although avapritinib, a novel targeted therapy, has significantly improved outcomes for SM, the efficacy of treatment for the associated hematologic neoplasm in patients with SM-AHN may be the primary determinant of long-term overall survival and progression-free survival. This report includes a review of relevant literature to provide insights into the clinical diagnosis and management of this rare entity.