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FDA Approves a Targeted Treatment for a Rare Form of Blood Cancer

Rye Brook, NY, June 23, 2021 - The U.S. Food and Drug Administration (FDA) last week approved avapritinib (Ayvakit®) for the treatment of advanced systemic mastocytosis (SM) in adults, including patients with aggressive SM, SM with associated hematologic neoplasm, and mast cell leukemia. Avapritinib is a targeted treatment that inhibits a mutation in the KIT gene, which drives about 95% of the cases of this rare type of blood cancer.

SM occurs when mast cells, a type of white cell, build up in the body. People with advanced SM face debilitating symptoms including organ damage and the overall survival time can vary from just six months to three-and-half years depending on the SM subtype.

This week’s FDA approval was based on results from the phase 1 EXPLORER trial and phase 2 PATHFINDER trial. In the trials, avapritinib was effective in patients with all types of SM, regardless of what type of prior therapy they had. The overall response rate in the two trials combined was 57%, with 28% of patients having a complete remission and 28% having a partial remission. Patients responded to treatment quickly (median time of 2 months) and median duration of response was more than three years.

LLS is supporting ongoing research into additional targeted, or precision treatments, like avapritinib. LLS researchers are leveraging advancements in genomics to discover cancer-driving genetic mutations so they can develop targeted treatments that can be used in place of toxic chemotherapies.

LLS precision research initiatives include the Beat AML® Master Clinical Trial, which aims to change the treatment paradigm for acute myeloid leukemia, one of the most lethal blood cancers. LLS is also applying lessons learned from Beat AML as we set out to fundamentally change how children with acute leukemia are treated by setting the groundwork for LLS PedAL, a global precision medicine pediatric master trial.