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An exon 19 deletion removes a few amino acids from the EGFR kinase and leaves it switched on. With L858R it makes up about 85 percent of EGFR-mutant lung cancer and is the classic gate for osimertinib and the other EGFR inhibitors.
In-frame deletions in exon 19 (most often E746_A750del) are the commonest sensitising EGFR mutation in lung adenocarcinoma. Every EGFR tyrosine kinase inhibitor label (osimertinib, erlotinib, gefitinib, afatinib, dacomitinib, and amivantamab with lazertinib) names 'exon 19 deletions or exon 21 L858R substitution mutations' detected by an FDA-approved test; osimertinib is also labelled as adjuvant therapy after resection and with chemoradiation in stage III disease. The cobas EGFR Mutation Test v2 (tissue and plasma), therascreen EGFR RGQ PCR, Oncomine Dx Target Test, FoundationOne CDx and Liquid CDx and Guardant360 CDx are companion diagnostics; the FDA list groups the TKIs under one device indication. Exon 19 deletions respond somewhat better to TKIs than L858R in the pooled trial data.
In plain words · A growth receptor that is mutated in some lung cancers and overproduced in others; the first great success of targeted pills.
An exon 19 deletion means an EGFR tablet, most often osimertinib, or amivantamab with lazertinib, is the first treatment for advanced lung cancer rather than chemotherapy or immunotherapy; after surgery, osimertinib for three years is also on label. Immunotherapy alone does not work well against these tumours, so the labels for PD-1 drugs exclude them.
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.
An in-frame deletion within exon 19 of EGFR detected by PCR or sequencing of tumour tissue, or of plasma cell-free DNA with tissue testing if plasma is negative.
“Exon 19 deletion or exon 21 L858R substitution mutation”
FDA: List of FDA-Authorized Companion Diagnostic Devices| Threshold | Drug | Cancer | Regulator | Source |
|---|---|---|---|---|
| EGFR exon 19 deletion or exon 21 L858R | Osimertinib | Non-small-cell lung cancer | FDA | label |
| EGFR exon 19 deletion or exon 21 L858R | Amivantamab | Non-small-cell lung cancer | FDA | label |
| EGFR exon 19 deletion or exon 21 L858R | Gefitinib | Non-small-cell lung cancer | FDA | label |
| EGFR exon 19 deletion or exon 21 L858R | Dacomitinib | Non-small-cell lung cancer | FDA | label |
| Device | Maker | Indication and sample | Drug | PMA / 510(k) |
|---|---|---|---|---|
| cobas EGFR Mutation Test v2 | Roche Molecular Systems | Non-Small Cell Lung Cancer (NSCLC) - Tissue or Plasma | OsimertinibErlotinibGefitinibAfatinib | P120019/S031 (10/27/2020) |
| therascreen EGFR RGQ PCR Kit | QIAGEN Manchester | Non-Small Cell Lung Cancer (NSCLC) - Tissue | Afatinib | P120022 (07/12/2013) |
| therascreen EGFR RGQ PCR Kit | QIAGEN Manchester | Non-Small Cell Lung Cancer (NSCLC) - Tissue | Dacomitinib | P120022/S018 (09/27/2018) |
| FoundationOne CDx | Foundation Medicine | Non-Small Cell Lung Cancer (NSCLC) - Tissue | OsimertinibErlotinibGefitinibAfatinib | P170019 (11/30/2017) |
| Guardant360 CDx | Guardant Health | Non-Small Cell Lung Cancer (NSCLC) - Plasma | Osimertinib | P200010 (08/07/2020) |
| Oncomine Dx Target Test | Life Technologies (Thermo Fisher Scientific) | Non-Small Cell Lung Cancer (NSCLC) - Tissue | Gefitinib | P160045 (06/22/2017) |
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.
Lung cancer in never-smokers is not smokers' lung cancer with the smoking removed; it is a different set of diseases with a different clock. The slow-growing piano subtype in particular is the argument that a screening test aimed at never-smokers would need to look for something other than what low-dose computed tomography was built to find.
It shows that the driver frequencies quoted in Western guidelines are population statistics rather than facts about the disease, which matters for how many patients anywhere are expected to benefit from a given medicine.
It is the practical guide to what to do after transformation: treat it as small-cell lung cancer with platinum and etoposide, expect central nervous system disease, and do not expect a checkpoint inhibitor to help.
It is the document that defines what a complete lung cancer molecular report looks like, and its asymmetry about plasma, rule in but never rule out, is the single most useful sentence in it.
Shares EGFR exon 20 insertion, Oncomine Dx Target Test, Genomic and evolutionary classification of lung cancer in never smokers, Guardant360 CDx and the tag biomarker.
Shares Oncomine Dx Target Test, Updated molecular testing guideline for the selection of lung cancer patients for treatment with targeted tyrosine kinase inhibitors, FoundationOne CDx / Liquid CDx, Non-small-cell lung cancer and the tag biomarker.
Shares Oncomine Dx Target Test, Updated molecular testing guideline for the selection of lung cancer patients for treatment with targeted tyrosine kinase inhibitors, FoundationOne CDx / Liquid CDx, Non-small-cell lung cancer and the tag biomarker.
Shares Updated molecular testing guideline for the selection of lung cancer patients for treatment with targeted tyrosine kinase inhibitors, FoundationOne CDx / Liquid CDx, Next-generation sequencing (NGS), Non-small-cell lung cancer and the tag biomarker.
Shares therascreen companion diagnostic kits (KRAS, EGFR, PIK3CA, FGFR, BRAF), FoundationOne CDx / Liquid CDx, Next-generation sequencing (NGS), Non-small-cell lung cancer and the tag biomarker.
Shares therascreen companion diagnostic kits (KRAS, EGFR, PIK3CA, FGFR, BRAF), Guardant360 CDx, Next-generation sequencing (NGS), Non-small-cell lung cancer and the tag biomarker.
Shares Updated molecular testing guideline for the selection of lung cancer patients for treatment with targeted tyrosine kinase inhibitors, FoundationOne CDx / Liquid CDx, Non-small-cell lung cancer and the tag biomarker.
Shares Oncomine Dx Target Test, Next-generation sequencing (NGS) and the tag biomarker.