Gastrointestinal Stromal Tumor
ICD-10 C49.4 · ICD-11 2B5B

Treatment of Metastatic Gastrointestinal Stromal Tumor with KIT or PDGFRA Mutation

Clinical Scenario

This protocol addresses patients with metastatic gastrointestinal stromal tumor (GIST) who carry a confirmed KIT or PDGFRA mutation — specifically excluding those with a KIT exon 9 mutation or a PDGFRA D842V mutation. Molecular genotyping is essential in this setting and guides the choice of therapy at each treatment line.

Mutation Profile & Diagnostic Context

For advanced or metastatic GIST, establishing the precise mutation genotype is a mandatory step before initiating or modifying treatment. The absence of KIT exon 9 and PDGFRA D842V variants defines a distinct clinical sub-population with its own recommended treatment sequence.

Treatment Approach (Summary — Partial)

Management of this mutation profile follows a defined sequential line approach. Third-line treatment for this population involves a multikinase inhibitor administered on an intermittent cycle schedule.

Full regimen, sequencing, and decision criteria available in the complete protocol below.
Instant Access to Structured Evidence-Based Regimens

References

DOI: 10.1177/17588359231192388

Genotype is mandatory for treating advanced/metastatic GIST patients (II,A).

Imatinib 400 mg daily is the recommended dose in the first line (I,A).

Standard third- and fourth-line treatments are, respectively, regorafenib 160 mg daily 3/1 (I,A) and ripretinib 150 mg once daily (I,A).

The multikinase inhibitor regorafenib is approved at the doses of 160 mg daily, 3 weeks on, 1 week off, as the third line of treatment based on the results of the phase III GRID trial, exhibiting a PFS of 4.8 months compared with 0.9 in the placebo arm.

View source ↗