FDA Approves Blueprint Medicines’ Rare Blood Disorder Treatment

Blueprint Medicines announced FDA approval of Ayvakit (avapritinib) for treatment of adults with indolent systemic mastocytosis (ISM), a rare hematologic disorder, on May 22, 2023. Avapritinib, a tyrosine-kinase (KIT) inhibitor that selectively inhibits KIT D816V, was previously approved for the treatment of systemic mastocytosis (1). According to a company press release, it is the first and only FDA-approved medicine designed to treat ISM.

FDA’s approval is based in part on findings from a Phase II, double-blind, placebo-controlled clinical trial (PIONEER). Patients who received avapritinib demonstrated significant improvements versus placebo in both the primary and all key secondary endpoints, improving overall symptoms and measures of mast cell burden.

"After decades of caring for people with indolent systemic mastocytosis, I have seen firsthand its profound impact on patients' underlying mast cell burden, symptoms, physical and mental health, and ability to work and participate in daily activities," said Cem Akin, professor of Medicine at the University of Michigan, and an investigator on the Phase II clinical trial. "Despite the use of multiple supportive care treatments, a considerable number of patients with indolent systemic mastocytosis continue to experience a substantial disease burden. [Avapritinib] advances the treatment of indolent systemic mastocytosis by targeting KIT D816V, the primary underlying cause of the disease, and establishes a new standard of care for a broad population of patients with this disorder. [Avapritinib] delivered statistically significant and consistent clinical improvements in the PIONEER trial, and based on these practice-changing data, I feel a tremendous sense of hope for the future for all those affected by the disease."

Source: Blueprint Medicines

1. FDA. FDA Approves Avapritinib for Advanced Systemic Mastocytosis. Press Release, June 16, 2021.