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Overall Treatment Strategy for Patients With Metastatic NSCLC With Activating EGFR Mutations
Hidetoshi Hayashi1, Ernest Nadal2, Jhanelle E Gray3
1Department of Medical Oncology, Kindai University Faculty of Medicine, Osaka-Sayama, Osaka, Japan.
Abstract:
Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (EGFR-TKIs) are standard of care in the first-line (1L) setting for patients with metastatic non-small cell lung cancer (mNSCLC) with activating EGFR mutations. EGFR-activating mutations are a predictive factor for response to EGFR-TKIs. Meta-analyses have shown that patients with exon 21_L858R mutations exhibit reduced sensitivity to EGFR-TKIs, resulting in inferior patient outcomes compared to those with exon 19 deletion mutations, with worse overall survival, progression-free survival, objective response, and disease control rates. Clinical activity observed with 1L therapy with first-generation (1G), second-generation (2G), and third-generation (3G) EGFR-TKIs is not permanent, and resistance inevitably develops in all cases, supporting the importance of overall treatment planning. The introduction of the 3G EGFR-TKI, osimertinib, provides an opportunity to overcome T790M-mediated resistance to 1G, and 2G EGFR-TKIs. Additionally, with the use of osimertinib, fewer T790M mutations are being detected as T790M is not a reported resistance mechanism to 3G EGFR-TKIs. However, there are currently no approved targeted therapies after 3G EGFR-TKIs. In order to further improve patient outcomes, there is a need to explore additional options for the overall treatment strategy for patients, including 1L and beyond. Combination of vascular endothelial growth factor (VEGF) inhibitors and EGFR-TKIs or chemotherapy and EGFR-TKIs may be a potential therapeutic approach in the 1L setting. This review discusses current treatment options for mNSCLC with activating EGFR mutations based on tumor, patient, and treatment characteristics and how an overall treatment plan may be developed.
Insights
First-line EGFR-TKIs are standard for EGFR-mutated NSCLC, but resistance necessitates treatment planning. Exon 21 mutations show less sensitivity, highlighting the need for improved strategies beyond third-generation inhibitors.
Area of Science:
- Oncology
- Medical Genetics
- Pharmacology
Background:
- Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are standard first-line therapy for metastatic non-small cell lung cancer (mNSCLC) with activating EGFR mutations.
- Patients with EGFR exon 21 L858R mutations demonstrate reduced sensitivity to EGFR-TKIs compared to those with exon 19 deletions, leading to poorer outcomes.
- Resistance to all generations of EGFR-TKIs inevitably develops, underscoring the need for comprehensive treatment strategies.
Purpose of the Study:
- To review current treatment options for mNSCLC with activating EGFR mutations.
- To discuss the development of an overall treatment plan considering tumor, patient, and treatment characteristics.
- To explore potential therapeutic approaches beyond third-generation EGFR-TKIs.
Main Methods:
- Literature review of current treatment options for mNSCLC with activating EGFR mutations.
- Analysis of tumor, patient, and treatment characteristics influencing therapeutic decisions.
- Discussion of resistance mechanisms and strategies to overcome them.
Main Results:
- First-generation (1G), second-generation (2G), and third-generation (3G) EGFR-TKIs are used in the first-line setting, with varying efficacy.
- Exon 21 L858R mutations are associated with inferior outcomes compared to exon 19 deletions.
- Osimertinib (a 3G EGFR-TKI) overcomes T790M resistance but no approved therapies exist post-3G EGFR-TKIs.
Conclusions:
- Developing an overall treatment plan is crucial for managing EGFR-mutated mNSCLC due to inevitable resistance.
- Combination therapies (e.g., VEGF inhibitors or chemotherapy with EGFR-TKIs) may offer future treatment avenues.
- Further research is needed to identify effective therapies beyond third-generation EGFR-TKIs to improve patient outcomes.
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