Treatment of Advanced or Metastatic NSCLC with EGFR Exon 19 Deletion or L858R Mutation

Advanced or metastatic non-small cell lung cancer (NSCLC) with a confirmed EGFR exon 19 deletion or EGFR L858R point mutation constitutes a molecularly defined subgroup with its own dedicated first-line treatment pathway.

Clinical Scenario

The exon 19 deletion and L858R substitution together account for approximately 85% to 90% of all EGFR mutations in NSCLC. Both alterations activate the tyrosine kinase domain and are associated with sensitivity to small-molecule EGFR tyrosine kinase inhibitors (TKIs), making molecular testing essential before initiating treatment.

First-Line Treatment Approach

Management is built around first-line targeted therapy — with multiple preferred and circumstance-specific options available depending on histologic subtype and other clinical factors. The full protocol specifies which regimens are preferred and under what conditions each applies.

Instant Access to Structured Evidence-Based Regimens

References

The two most common EGFR mutations in NSCLC are exon 19 deletions and L858R; these represent approximately 85% to 90% of all EGFR mutations in NSCLC.

Both result in activation of the tyrosine kinase domain and are associated with sensitivity to small-molecule EGFR tyrosine kinase inhibitors (TKIs).

In the first-line setting, the NCCN NSCLC Panel recommends the following as preferred and category 1 options for patients with advanced or metastatic NSCLC with EGFR exon 19 deletion or L858R mutation: single-agent osimertinib, osimertinib in combination with (carboplatin or cisplatin)/pemetrexed (for nonsquamous histology), or lazertinib + amivantamab-vmjw.

Single-agent afatinib, dacomitinib, erlotinib, gefitinib, or lazertinib are first-line treatment options that may be useful in certain circumstances.

Erlotinib in combination with bevacizumab (if nonsquamous and no recent history of hemoptysis) or erlotinib in combination with ramucirumab are also first-line treatment options that may be useful in certain circumstances.

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