End of September, a new therapy option for GIST patients with D842V mutation was approved for the EU: Avapritinib (Ayvakyt®) from Blueprint Medicines is a highly selective tyrosine kinase inhibitor. It is directed against the D842V mutation in exon 18, which has been shown to be resistant to all drugs available to date.
The approval is based on the results of two clinical studies in phase I and phase III, in which the drug showed a high and durable response: The overall response rate in the phase I Navigator study was 95 percent and lasted for an average of 22.1 months. The median progression-free survival (time to progression of the disease) was 24 months.
This approval makes the so-called mutational analysis in GIST even more important. This analysis determines the exact location of the mutation in the receptor protein. It is crucial for therapy decision and allows conclusions about the possible course of the disease. With the availability of the new drug avapritinib, it is now more important than ever to carry out mutational tests before initial treatment. Thus, GIST patients with the PDGFRA D842V mutation can immediately begin with the correct and currently only effective therapy for their tumor type.