Blueprint’s Ayvakit Mastocytosis Results Raise Commercial Uncertainty

Blueprint Medicines Corporation’s Phase III PIONEER trial data for Ayvakit (avapritinib) in indolent systemic mastocytosis (ISM) will likely prove sufficient for US Food and Drug Administration approval, but it has raised questions about how much it will drive commercial adoption, as the magnitude of benefit shown in the trial came in below what investors had hoped for.

Blueprint announced 17 August topline results from part 2 of PIONEER, saying it demonstrated clinically meaningful and highly statistically significant improvements across primary and key secondary endpoints,