FDA nod for Blueprint's Ayvakit to treat ISM

The US Food and Drug Administration (FDA) yesterday approved Ayvakit (avapritinib) for the treatment of adults with indolent systemic mastocytosis (ISM), said Blueprint Medicines (Nasdaq: BPMC), whose shares rose 3.1% to $58.00 on the news.

Initially approved by the FDA in 2020 for gastrointestinal stromal tumors, the drug, which is designed to inhibit D816V mutant KIT, was also cleared in 2021 to treat adults with advanced systemic mastocytosis.

Advanced SM, where Ayvakit is currently approved, only accounts for 5% to 10% of all SM cases. With an approval in indolent SM, the drug could reach $1.5 billion in annual peak sales in SM, according to Blueprint, up from just $111 million in 2022.