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PDGFRA D842V drives about 5 percent of gastrointestinal stromal tumours and is resistant to imatinib. Avapritinib is the approved drug for GISTs with PDGFRA exon 18 mutations including D842V.
Exon 18 mutations sit in the activation loop; D842V, the commonest, stabilises the active kinase and blocks imatinib, sunitinib and regorafenib binding. Avapritinib (Ayvakit, 2020) is labelled for unresectable or metastatic GIST harbouring a PDGFRA exon 18 mutation, including D842V, and the therascreen PDGFRA RGQ PCR Kit is its companion diagnostic (P210002, 2023). Non-D842V exon 18 mutations remain partly imatinib-sensitive, so the exact variant is reported.
In plain words · PDGFRA is a growth-factor receptor mutated in about 10% of GISTs, including the D842V mutation that resists imatinib but responds to avapritinib.
If your GIST carries a PDGFRA D842V mutation, imatinib is unlikely to work and avapritinib tablets are the on-label treatment for advanced disease. Every GIST should have KIT and PDGFRA sequenced before treatment, because the mutation decides the drug and the dose.
Written only from the label or guideline text cited on this page. Not medical advice; your own report and the reading your team gives it come first.
A PDGFRA exon 18 mutation, including D842V, by the therascreen PDGFRA RGQ PCR Kit or sequencing of tumour tissue.
“PDGFRA: D842V”
FDA: List of FDA-Authorized Companion Diagnostic Devices| Threshold | Drug | Cancer | Regulator | Source |
|---|---|---|---|---|
| PDGFRA exon 18 mutation including D842V | Avapritinib | PDGFRA D842V-mutant GIST | FDA | label |
| Device | Maker | Indication and sample | Drug | PMA / 510(k) |
|---|---|---|---|---|
| therascreen PDGFRA RGQ PCR Kit | QIAGEN | Gastrointestinal Stromal Tumors (GIST) - Tissue | Avapritinib | P210002 (06/29/2023) |
Matched on the name and aliases of the readout in the title, setting and summary of each trial; a match is a mention, not proof the readout was an entry criterion.
Shares Gastrointestinal stromal tumour (GIST), Imatinib and the tag gist.
Shares PDGFRA D842V-mutant GIST, Gastrointestinal stromal tumour (GIST) and the tag gist.
Shares Gastrointestinal stromal tumour (GIST) and the tag gist.
Shares therascreen companion diagnostic kits (KRAS, EGFR, PIK3CA, FGFR, BRAF) and the tag biomarker.
Shares PDGFRA D842V-mutant GIST, Avapritinib, Gastrointestinal stromal tumour (GIST).
Shares therascreen companion diagnostic kits (KRAS, EGFR, PIK3CA, FGFR, BRAF) and the tag biomarker.
Shares PDGFRA D842V-mutant GIST, Avapritinib.
Shares therascreen companion diagnostic kits (KRAS, EGFR, PIK3CA, FGFR, BRAF) and the tag biomarker.