FDA approves Ayvakit for advanced systemic mastocytosis
Click Here to Manage Email Alerts
The FDA approved avapritinib for treatment of adults with advanced systemic mastocytosis.
The indication allows the agent to be used by patients with aggressive systemic mastocytosis, systemic mastocytosis with an associated hematologic neoplasm, or mast cell leukemia.
Avapritinib (Ayvakit, Blueprint Medicines) — a kinase inhibitor — is the first approved targeted therapy designed to inhibit D816V-mutant KIT, which causes nearly all cases of the rare hematologic disorder.
“Advanced systemic mastocytosis is a debilitating disease characterized by extensive damage in multiple organ systems due to mast cell infiltration, and new treatment options are urgently needed to address these life-threatening complications,” Daniel DeAngelo, MD, PhD, chief of the division of leukemia at Dana-Farber Cancer Institute, said in a Blueprint Medicines-issued press release. “Avapritinib will clearly establish a new standard of care for patients with advanced systemic mastocytosis. The FDA approval was based on data showing robust and durable responses, including complete remissions, and a favorable safety profile. For [patients with advanced systemic mastocytosis], the approval of avapritinib shifts the treatment paradigm toward precision therapy that targets the primary driver of mastocytosis.”
The FDA based the approval on results of the multicenter, open-label, single-arm EXPLORER and PATHFINDER trials, both of which enrolled patients with systemic mastocytosis.
Overall response rate as assessed by a central committee served as the main efficacy outcome. Other efficacy measures included duration of response, time to response and changes in individual measures of mast cell burden.
The 53 study participants received 200 mg avapritinib daily.
Researchers reported a combined ORR of 57% (95% CI, 42-70); 28% of patients achieved complete remission. Median time to response was 2.1 months and median duration of response was 38.3 months (95% CI, 19 to not estimable).
The most common adverse events reported among avapritinib-treated patients with advanced systemic mastocytosis included edema, diarrhea, nausea and fatigue/asthenia.
The FDA previously granted priority review, breakthrough therapy designation and orphan drug designation to avapritinib for this indication.
The agency previously approved avapritinib for treatment of adults with unresectable or metastatic gastrointestinal stromal tumors that harbor a PDGFRA exon 18 mutation, including PDGFRA D842V mutations.
Click Here to Manage Email Alerts