Gastrointestinal stromal tumor (GIST) harbouring the PDGFRA D842V mutation represents a molecularly distinct sub-population requiring a specific treatment approach that differs from standard GIST management.
The PDGFRA D842V mutation — a substitution of aspartic acid by valine at codon 842 in PDGFRA exon 18 — occurs in approximately 5% of all GIST cases. This mutation is known to confer resistance to standard therapeutic agents used in GIST, making precise molecular characterisation essential before treatment selection.
A targeted agent with specific activity against this mutation is available and is recommended as the first-line treatment for this sub-population. The complete regimen — including agent, dosing, and clinical criteria — is provided in the full structured protocol.
The substitution of aspartic acid by valine at codon 842 in PDGFRA exon 18 (D842V) occurs in ~5% of all GIST and is known to be resistant to all therapeutic agents.
Avapritinib 300 mg daily is the only effective treatment available for PDGFRA D842V-mutant GIST and it should be introduced, if possible, as the first line (III,A).