Ahead of FDA decision, Blueprint puts out full data for expanded Ayvakit label
Blueprint Medicines presented the full dataset for its drug Ayvakit at a medical conference over the weekend as it heads towards an FDA decision in May. Blueprint is hoping to expand Ayvakit’s label into a less advanced form of systemic mastocytosis, a rare disease in which too many mast cells, a type of white blood cell, build up in the body.
The drug was approved for the advanced form of the disease in 2021. Blueprint reported topline data for the Phase III PIONEER trial in August, but left a key datapoint in the air.
This release included data on how many patients with indolent SM responded to Blueprint’s drug, a key secondary endpoint. The responder rate — the proportion of patients with a ≥30% decrease in total symptom score — was 45.4% at 24 weeks for those who got Ayvakit compared to 29.6% for those who got placebo. The p-value was p=0.009, so the difference was statistically significant.
At 48 weeks, the responder rate for participants who got Ayvakit was 60.7%. Blueprint did not include data on the 48-week responder rate for the placebo group.
Previously, responder rate was the primary endpoint of the study, but Blueprint swapped its primary and secondary endpoints following a recommendation from the FDA. The study’s primary endpoint is now mean change in total symptom score.
The FDA’s decision deadline for expanding Ayvakit’s label to adults with indolent SM is May 22.