Blueprint Medicines announced a submission of a supplemental new drug application to the US Food and Drug Administration (FDA) for avapritinib (Ayvakit®) to treat adults with indolent systemic mastocytosis (SM).

The submission, announced via news release, is based on positive data from the randomized, placebo-controlled PIONEER trial, which will be presented at the American Academy of Allergy, Asthma & Immunology annual meeting taking place February 24th through 27th, 2023.

“By targeting the primary driver of SM with Ayvakit, we are seeking to transform treatment beyond symptom-directed therapy, modify the course of disease and ultimately, make a meaningful difference in patients’ lives,” said Becker Hewes, MD, chief medical officer at Blueprint Medicines. “Our FDA filing marks the first regulatory application seeking approval for the treatment of indolent SM, and we look forward to working closely with the agency toward our goal of bringing Ayvakit to indolent SM patients as quickly as possible.”

SM is a rare disease driven by mutations in the KIT D816V gene, which leads to uncontrolled mast cell proliferation and activation. The disorder leads to chronic, unexpected, and severe symptoms in multiple organs in the body. Symptoms include anaphylaxis, rashes, diarrhea, pruritus, fatigue, brain fog, and bone pain.

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Most patients have indolent or smoldering SM, which are nonadvanced cases for which there are currently no approved treatments. Advanced SM includes both mast cell activation symptoms and a poor prognosis due to organ damage from the infiltration of mast cells.

Avapritinib is a kinase inhibitor designed to potently and selectively inhibit the KIT D816V mutation, which represents the underlying cause of SM in most cases. The FDA has already granted breakthrough therapy designation to avapritinib for adults with moderate to severe indolent SM.


Blueprint Medicines submits supplemental new drug application to FDA for Ayvakit® (avapritinib) for the treatment of indolent systemic mastocytosis. News release. Blueprint Medicines Corp.; November 22, 2022.