Early access (ex-temporary authorization for use) post-marketing authorization (MA) was granted to avapritinib (Ayvakit) from the Blueprint Medicines laboratory in systemic mastocytosis for a period of one year. The European marketing authorization was obtained in March 2022 but avapritinib is not yet reimbursed by Medicare, a request is in progress.
The exact indication for early access is use “as monotherapy for the treatment of adult patients with aggressive systemic mastocytosis (ASM), systemic mastocytosis associated with haematological neoplasm (SM-AHN) or mast cell leukemia (MCL), after failure or intolerance to midostaurin”.
Systemic mastocytosis is a chronic malignant haemopathy linked to the abnormal proliferation of mast cells in various tissues. The advanced form is thus characterized by various organ damage: hepatomegaly, bone damage with or without fractures, splenomegaly, medullary damage responsible for at least one cytopenia, malabsorption with weight loss.
Avapritinib is a tyrosine kinase inhibitor designed to selectively and effectively inhibit the KIT D816V gene mutation, which causes systemic mastocytosis in approximately 95% of cases.
The treatments currently recommended for advanced systemic mastocytosis include midostaurin, avapritinib (the only medicinal products with Marketing Authorization in the indication), cladribine, interferon alpha and imatinib (used off-label).
According to a Blueprint Medicines press release