Avapritinib (Ayvakit)

Selective type 1 KIT D816V inhibitor

Response rate
PIONEER: significant symptom reduction vs placebo; AdvSM: 30% molecular response
Onset
Weeks
Route
Oral 25mg daily (ISM) / 200mg daily (AdvSM)
Line
1st
IgM effect
N/A

Evidence summary

Highly selective inhibitor of KIT D816V with potent activity against the mutant receptor. First and only FDA-approved therapy for ISM (May 2023). In PIONEER trial, avapritinib 25mg daily significantly reduced symptoms (TSS -15.6 vs -9.2, P<0.003) and achieved >=50% tryptase reduction in 54% of patients vs 0% placebo. In AdvSM, achieved molecular responses with KIT D816V becoming undetectable in 30% of patients.