Blueprint Announces EMA Validation of Type II Variation Marketing Authorization Application for AYVAKYT

Blueprint Medicines announced the European Medicines Agency (EMA) has validated the company's Type II variation marketing authorization application for AYVAKYT® (avapritinib) for the treatment of advanced systemic mastocytosis (SM). Validation of the application confirms that the submission is sufficiently complete to begin the formal review process. The European Commission has granted orphan medicinal product designation to AYVAKYT for the treatment of mastocytosis.

"AYVAKYT represents a promising approach to address the needs of patients with advanced systemic mastocytosis, a rare, life-threatening disease characterized by severe organ damage," said Paul Beresford, Senior Vice President and General Manager, International, at Blueprint Medicines. "In robust datasets across our registrational trials, AYVAKYT has shown complete and durable remissions not typically observed in this patient population, and a generally well-tolerated safety profile. We look forward to working closely with the EMA during the review process, and aim to bring the first precision therapy to patients in Europe that targets the primary driver of the disease."

AYVAKYT, a potent and selective inhibitor of D816V mutant KIT, is being developed to treat advanced and non-advanced forms of SM. Last month, Blueprint Medicines announced that the U.S. Food and Drug Administration (FDA) accepted the company's supplemental new drug application and granted priority review for AYVAKIT™ (avapritinib) for the treatment of advanced SM.

SM is a rare disease driven by the KIT D816V mutation. Uncontrolled proliferation and activation of mast cells result in chronic, severe and often unpredictable symptoms for patients across the spectrum of SM. The vast majority of those affected have non-advanced (indolent or smoldering) SM, with debilitating symptoms that lead to a profound, negative impact on quality of life. A minority of patients have advanced SM, which encompasses a group of high-risk SM subtypes including aggressive SM, SM with an associated hematological neoplasm and mast cell leukemia. In addition to mast cell activation symptoms, advanced SM is associated with organ damage due to mast cell infiltration and poor survival.

Debilitating symptoms, including anaphylaxis, maculopapular rash, pruritis, diarrhea, brain fog, fatigue and bone pain, often persist across all forms of SM despite treatment with a number of symptomatic therapies. Patients often live in fear of severe, unexpected symptoms, have limited ability to work or perform daily activities, and isolate themselves to protect against unpredictable triggers. Currently, there are no approved therapies for the treatment of SM that selectively inhibit D816V mutant KIT.

AYVAKYT (avapritinib) is a kinase inhibitor approved by the European Commission for the treatment of adults with unresectable or metastatic gastrointestinal stromal tumors (GIST) harboring the PDGFRA D842V mutation. This medicine was approved by the FDA for the treatment of adults with unresectable or metastatic GIST harboring a PDGFRA exon 18 mutation, including PDGFRA D842V mutations, under the brand name AYVAKIT.

AYVAKIT/AYVAKYT is not approved for the treatment of any other indication, including SM, in the U.S. by the FDA or in Europe by the European Commission, or for any indication in any other jurisdiction by any other health authority.

Blueprint Medicines is developing AYVAKIT globally for the treatment of advanced and indolent SM. The FDA granted breakthrough therapy designation to AYVAKIT for the treatment of advanced SM, including the subtypes of aggressive SM, SM with an associated hematological neoplasm and mast cell leukemia, and for the treatment of moderate to severe indolent SM.

Blueprint Medicines has an exclusive collaboration and license agreement with CStone Pharmaceuticals for the development and commercialization of AYVAKIT in Mainland China, Hong Kong, S.A.R., China, Macau, S.A.R., China and Taiwan, China. Blueprint Medicines retains development and commercial rights for AYVAKIT in the rest of the world.