Precision medicine in the first-line treatment of EGFR-mutated non-small cell lung cancer: moving beyond “one-size-fits-all”

For the past several years, the first-line treatment of epidermal growth factor receptor (EGFR)-mutated advanced non-small cell lung cancer (NSCLC) had been simple: a single-agent regimen. The phase 3 FLAURA trial established monotherapy with third generation tyrosine kinase inhibitor (TKI) osimertinib as the global standard of care, offering a median overall survival (OS) of 38.6 months with a favorable safety profile (1,2). This “pill-a-day” strategy represented a highly effective, well-tolerated, and universally applicable therapeutic approach. However, the final OS analysis of the FLAURA2 trial signals the end of this era of simplicity and the arrival of a more complex decision-making landscape (3).

The FLAURA2 trial investigated whether the addition of platinum-pemetrexed chemotherapy to osimertinib could improve outcomes compared with osimertinib alone (3), although a significant improvement in progression-free survival (PFS; the primary end point) had already been reported (4). The combination therapy achieved a median OS of 47.5 months compared with 37.6 months in the monotherapy group, corresponding to a hazard ratio (HR) for death of 0.77 [95% confidence interval (CI): 0.61–0.96]. This approximate 10-month extension in median survival breaks the ceiling set by monotherapy and confirms that treatment intensification can translate into a tangible survival benefit. The incidence of grade 3 or higher adverse events was more than double in the combination group (70%) compared with the monotherapy group (34%), driven largely by chemotherapy-related myelosuppression (3). Concurrently, the phase 3 MARIPOSA trial introduced a chemotherapy-free intensification option, demonstrating that the combination of the EGFR/MET bispecific antibody amivantamab and the third-generation TKI lazertinib significantly improved PFS and OS compared with osimertinib monotherapy (HR 0.70; 95% CI: 0.58–0.85 and HR 0.75; 95% CI: 0.61–0.92, respectively) (5,6). The challenge we now face is to identify who benefits from this intensification and determine which intensification strategy is the best for each patient. Our goal when treating patients with uncurable cancer is to prolong survival while maintaining quality of life, and focus must shift to a stratified approach guided by specific clinical and molecular features such as mutation subtype and regional contexts.

EGFR mutations can be broadly categorized into three groups: common mutations, uncommon mutations, and exon 20 insertions. Common mutations consist of exon 19 deletions (Ex19del) and L858R mutation, which together account for over 80% of all EGFR mutations in NSCLC (7). Common EGFR-mutant lung cancers have long been treated as a relatively uniform molecular subset. However, accumulated evidence suggests that Ex19del and L858R mutations are biologically distinct entities rather than interchangeable variants (8,9). Structural analyses have revealed critical differences between Ex19del and L858R mutations. Ex19del shifts the a-C helix, locking the kinase domain into an active conformation that is exceptionally sensitive to EGFR TKIs (10). By contrast, the L858R substitution occurs on the activation loop, distant from the ATP-binding pocket (11). These structural differences may explain why L858R tumors have consistently shown a trend toward shorter PFS and OS across all generations of TKIs compared with Ex19del tumors (12-17).

In FLAURA2, the addition of platinum-pemetrexed chemotherapy yielded a remarkably consistent survival benefit across mutation subtypes. The HR for OS was 0.76 (95% CI: 0.56–1.02) for Ex19del and 0.76 (95% CI: 0.55–1.07) for L858R (3). This uniformity suggests that chemotherapy acts as a biologically agnostic pressure. Because cytotoxic agents eliminate tumor clones irrespective of their specific kinase conformation, their efficacy is preserved even in the L858R subgroup. Despite the inherent biological challenges of L858R tumors, the “broad-spectrum” nature of chemotherapy may confer benefit.

In contrast, the MARIPOSA trial illustrates the limitations of target-specific intensification for L858R (5,6). While the Ex19del subgroup achieved a profound survival improvement with the addition of amivantamab (HR 0.66; 95% CI: 0.50–0.86), the benefit in the L858R subgroup was notably attenuated (HR 0.90; 95% CI: 0.67–1.21). Unlike the uniform success of chemotherapy, the efficacy of this pathway-focused intensification appears to be dependent on the mutation type.

Why does the magnitude of survival gain in the L858R subgroup attenuate with dual-target blockade but remain steady with chemotherapy? The answer may lie in the nature of oncogene addiction. Ex19del tumors typically exhibit “deep addiction” to the EGFR signaling axis, making them exceptionally sensitive to amivantamab, which precisely blocks EGFR and MET signaling (18). Conversely, L858R may act as a “weaker driver”. These tumors may be less strictly dependent on the EGFR-MET axis alone and potentially rely on a broader network of survival signals to maintain viability. Therefore, for L858R tumors, which may not be fully controlled by suppressing EGFR and MET, the chemotherapy appears to yield a consistent survival benefit. When interpreting these divergent outcomes, it is important to acknowledge that direct comparability is limited by inherent differences in study design (e.g., open-label in FLAURA2 vs. blinded control in MARIPOSA), patient populations, and endpoints. Furthermore, it is crucial to emphasize that these observations stem from exploratory subgroup analyses. Nevertheless, they generate the hypothesis that cytotoxic intensification may offer a reliable option for the biological heterogeneity of L858R tumors.

Beyond mutation subtypes, the geographic and racial subgroup analyses of these trials offer another critical dimension for stratification, though they remain strictly hypothesis-generating. Specifically, the data from FLAURA2 and MARIPOSA differ regarding the benefit of intensification in Asian populations.

In FLAURA2, racial disparity is crucial. The non-Asian population experienced significant survival benefits from the addition of chemotherapy (HR 0.56, 95% CI: 0.39–0.82). However, among the Asian non-Chinese subgroup, this benefit was not observed (HR 1.00, 95% CI: 0.71–1.40). In contrast, the MARIPOSA trial demonstrated a different efficacy profile. The benefit of the amivantamab-lazertinib combination was remarkably consistent across racial subgroups, with an HR of 0.74 (95% CI: 0.54–1.00) in non-Asian patients and 0.75 (95% CI: 0.58–0.98) in Asian patients.

Again, the observation regarding the limited benefit of platinum-based intensification in the Asian non-Chinese population remains an exploratory subgroup finding. Therefore, while these regional differences are of clinical interest, the definitive efficacy of chemotherapy intensification in this specific demographic warrants prospective validation before influencing routine clinical practice.

Taken together, the era of a “one-size-fits-all” monotherapy for EGFR-mutated NSCLC has ended, replaced by a landscape defined by choices. Given the increased risk of adverse events associated with intensification, the data from FLAURA2 and MARIPOSA do not mandate intensification for all (19). Furthermore, these data argue against a binary framing of “combination versus monotherapy”. Instead, they support a model of precision intensification guided by mutation biology and regional context. In such a model, treatment selection would incorporate multiple dimensions: EGFR mutation subtype, baseline tumor burden, patient fitness, and healthcare infrastructure. The first-line regimen for EGFR-mutated NSCLC should be selected after a shared decision-making discussion with the patient about the risks and benefits.

We may also need to consider adaptive therapeutic platforms in which the intensification strategy is assigned based on baseline molecular risk features. For example, patients with MET amplification might preferentially receive dual EGFR/MET targeting. Conversely, those with high clonal diversity or non-targetable co-mutations might benefit more from addition of chemotherapy. Such approaches would move beyond static mutation identification toward the dynamic modulation of evolutionary pressure.

The recently reported SACHI trial adds another dimension to this adaptive paradigm, validating the utility of biomarker-driven salvage therapy (20). In patients with MET amplification identified following progression on EGFR-TKIs, the combination of savolitinib plus osimertinib demonstrated superior PFS compared with platinum-doublet chemotherapy, with a HR of 0.32 (95% CI: 0.20–0.53) in the post-third-generation TKI subgroup. This finding differentially impacts strategic choices depending on the first-line regimen. For those treated with FLAURA2, who have utilized platinum upfront, it provides a crucial targeted salvage pathway if MET-driven resistance develops. Conversely, for MARIPOSA, given that the regimen already suppresses MET signaling, MET amplification is an unlikely resistance mechanism (21), implying that subsequent therapy would likely require a switch to alternative modalities.

Furthermore, the integration of antibody-drug conjugates (ADCs) targeting trophoblast cell surface antigen 2 (TROP2) adds a new layer of complexity to regimen sequencing. If we select platinum-pemetrexed chemotherapy as the intensification strategy in the first-line therapy (FLAURA2), we effectively spend the cytotoxic card early. This strategy aligns with the current eligibility criteria for agents like datopotamab deruxtecan, which currently requires prior targeted therapy and platinum-based chemotherapy (TROPION-Lung01 and TROPION-Lung05) (22,23). In contrast, while selecting amivantamab-lazertinib (MARIPOSA) preserves platinum-based chemotherapy as a robust option, clinical evidence supporting the immediate use of datopotamab deruxtecan in this platinum-naive setting remains unestablished. This scenario necessitates a return to standard platinum doublets or favors alternative ADCs, such as sacituzumab tirumotecan, which may be deployable in the immediate post-TKI setting (OptiTROP-Lung04) (24). In addition, it is important to note that the MARIPOSA trial design prohibited crossover from the osimertinib monotherapy arm to the amivantamab-containing regimen. However, MARIPOSA-2 trial demonstrated that the addition of amivantamab to chemotherapy significantly improved PFS in patients progressing on osimertinib (25). Consequently, in current clinical practice, strategies that do not include amivantamab in the first-line setting still preserve access to this agent. Notably, ivonescimab, a first-in-class EGFR/VEGF bispecific antibody recently approved in China, has demonstrated significant clinical benefit in patients progressing on EGFR-TKIs, offering another possible salvage pathway (26). The emergence of effective second- and third-line options makes the selection of the first-line regimen more complex, requiring a strategic approach that anticipates the entire therapeutic journey rather than focusing solely on the initial intervention.

We may also move beyond static pretreatment stratification to dynamic, on-treatment stratification using circulating tumor DNA (ctDNA). Early clearance of ctDNA may serve as an early indicator of treatment efficacy (27). Rather than committing all patients to upfront intensification, an adaptive strategy may be implemented: start with osimertinib monotherapy and assess ctDNA clearance. Patients with uncleared ctDNA (molecular non-responders) could be escalated to combination therapy, while molecular responders would continue with monotherapy, sparing them unnecessary toxicity. Such a dynamic approach would further refine the precision medicine paradigm, treating the patient’s real-time response rather than just their baseline diagnosis.

Ultimately, the question raised by FLAURA2 is not only whether chemotherapy should return to the first-line setting, but also whether we are prepared to abandon therapeutic averaging. The era of a “one-size-fits-all” monotherapy for EGFR-mutated NSCLC has ended, replaced by biologically rational intensification tailored to both tumor and context. FLAURA2 provides evidence that early therapeutic pressure can extend survival. The next task is to determine which tumors require this approach and to determine the optimal strategy.

Acknowledgments

None.

Footnote

Provenance and Peer Review: This article was commissioned by the editorial office, Translational Lung Cancer Research. The article has undergone external peer review.

Peer Review File: Available at https://tlcr.amegroups.com/article/view/10.21037/tlcr-2026-1-0223/prf

Funding: None.

Conflicts of Interest: Both authors have completed the ICMJE uniform disclosure form (available at https://tlcr.amegroups.com/article/view/10.21037/tlcr-2026-1-0223/coif). H.I. reports honoraria from Astra Zeneca. H.K. reports honoraria from Astra Zeneca, Johnson & Johnson, and Daiichi Sankyo. The authors have no other conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. Soria JC, Ohe Y, Vansteenkiste J, et al. Osimertinib in Untreated EGFR-Mutated Advanced Non-Small-Cell Lung Cancer. N Engl J Med 2018;378:113-25. [Crossref] [PubMed]
2. Ramalingam SS, Vansteenkiste J, Planchard D, et al. Overall Survival with Osimertinib in Untreated, EGFR-Mutated Advanced NSCLC. N Engl J Med 2020;382:41-50. [Crossref] [PubMed]
3. Jänne PA, Planchard D, Kobayashi K, et al. Survival with Osimertinib plus Chemotherapy in EGFR-Mutated Advanced NSCLC. N Engl J Med 2026;394:27-38. [Crossref] [PubMed]
4. Planchard D, Jänne PA, Cheng Y, et al. Osimertinib with or without Chemotherapy in EGFR-Mutated Advanced NSCLC. N Engl J Med 2023;389:1935-48. [Crossref] [PubMed]
5. Cho BC, Lu S, Felip E, et al. Amivantamab plus Lazertinib in Previously Untreated EGFR-Mutated Advanced NSCLC. N Engl J Med 2024;391:1486-98. [Crossref] [PubMed]
6. Yang JC, Lu S, Hayashi H, et al. Overall Survival with Amivantamab-Lazertinib in EGFR-Mutated Advanced NSCLC. N Engl J Med 2025;393:1681-93. [Crossref] [PubMed]
7. Kobayashi Y, Mitsudomi T. Not all epidermal growth factor receptor mutations in lung cancer are created equal: Perspectives for individualized treatment strategy. Cancer Sci 2016;107:1179-86. [Crossref] [PubMed]
8. Cho J, Chen L, Sangji N, et al. Cetuximab response of lung cancer-derived EGF receptor mutants is associated with asymmetric dimerization. Cancer Res 2013;73:6770-9. [Crossref] [PubMed]
9. Okabe T, Okamoto I, Tamura K, et al. Differential constitutive activation of the epidermal growth factor receptor in non-small cell lung cancer cells bearing EGFR gene mutation and amplification. Cancer Res 2007;67:2046-53. [Crossref] [PubMed]
10. Carey KD, Garton AJ, Romero MS, et al. Kinetic analysis of epidermal growth factor receptor somatic mutant proteins shows increased sensitivity to the epidermal growth factor receptor tyrosine kinase inhibitor, erlotinib. Cancer Res 2006;66:8163-71. [Crossref] [PubMed]
11. Eck MJ, Yun CH. Structural and mechanistic underpinnings of the differential drug sensitivity of EGFR mutations in non-small cell lung cancer. Biochim Biophys Acta 2010;1804:559-66. [Crossref] [PubMed]
12. Maemondo M, Inoue A, Kobayashi K, et al. Gefitinib or chemotherapy for non-small-cell lung cancer with mutated EGFR. N Engl J Med 2010;362:2380-8. [Crossref] [PubMed]
13. Goto K, Nishio M, Yamamoto N, et al. A prospective, phase II, open-label study (JO22903) of first-line erlotinib in Japanese patients with epidermal growth factor receptor (EGFR) mutation-positive advanced non-small-cell lung cancer (NSCLC). Lung Cancer 2013;82:109-14. [Crossref] [PubMed]
14. Fukuoka M, Wu YL, Thongprasert S, et al. Biomarker analyses and final overall survival results from a phase III, randomized, open-label, first-line study of gefitinib versus carboplatin/paclitaxel in clinically selected patients with advanced non-small-cell lung cancer in Asia (IPASS). J Clin Oncol 2011;29:2866-74. [Crossref] [PubMed]
15. Zhou C, Wu YL, Chen G, et al. Final overall survival results from a randomised, phase III study of erlotinib versus chemotherapy as first-line treatment of EGFR mutation-positive advanced non-small-cell lung cancer (OPTIMAL, CTONG-0802). Ann Oncol 2015;26:1877-83. [Crossref] [PubMed]
16. Yang JC, Wu YL, Schuler M, et al. Afatinib versus cisplatin-based chemotherapy for EGFR mutation-positive lung adenocarcinoma (LUX-Lung 3 and LUX-Lung 6): analysis of overall survival data from two randomised, phase 3 trials. Lancet Oncol 2015;16:141-51. [Crossref] [PubMed]
17. Sheng M, Wang F, Zhao Y, et al. Comparison of clinical outcomes of patients with non-small-cell lung cancer harbouring epidermal growth factor receptor exon 19 or exon 21 mutations after tyrosine kinase inhibitors treatment: a meta-analysis. Eur J Clin Pharmacol 2016;72:1-11. [Crossref] [PubMed]
18. Moores SL, Chiu ML, Bushey BS, et al. A Novel Bispecific Antibody Targeting EGFR and cMet Is Effective against EGFR Inhibitor-Resistant Lung Tumors. Cancer Res 2016;76:3942-53. [Crossref] [PubMed]
19. Herbst RS. Navigating the Evolving Landscape of EGFR-Mutated NSCLC. N Engl J Med 2026;394:87-91. [Crossref] [PubMed]
20. Lu S, Wang J, Yang N, et al. Savolitinib plus osimertinib versus chemotherapy for advanced, EGFR mutation-positive, MET-amplified non-small-cell lung cancer in China (SACHI): interim analysis of a multicentre, open-label, phase 3 randomised controlled trial. Lancet 2026;407:375-87. [Crossref] [PubMed]
21. Hayashi H, Besse B, Lee SH, et al. PT1.03.06 Mechanisms of Acquired Resistance to First-Line Amivantamab Plus Lazertinib Vs Osimertinib: Updated Analysis from MARIPOSA. J Thorac Oncol 2025;20:S592.
22. Ahn MJ, Tanaka K, Paz-Ares L, et al. Datopotamab Deruxtecan Versus Docetaxel for Previously Treated Advanced or Metastatic Non-Small Cell Lung Cancer: The Randomized, Open-Label Phase III TROPION-Lung01 Study. J Clin Oncol 2025;43:260-72. [Crossref] [PubMed]
23. Sands J, Ahn MJ, Lisberg A, et al. Datopotamab Deruxtecan in Advanced or Metastatic Non-Small Cell Lung Cancer With Actionable Genomic Alterations: Results From the Phase II TROPION-Lung05 Study. J Clin Oncol 2025;43:1254-65. [Crossref] [PubMed]
24. Fang W, Wu L, Meng X, et al. Sacituzumab Tirumotecan in EGFR-TKI-Resistant, EGFR-Mutated Advanced NSCLC. N Engl J Med 2026;394:13-26. [Crossref] [PubMed]
25. Passaro A, Wang J, Wang Y, et al. Amivantamab plus chemotherapy with and without lazertinib in EGFR-mutant advanced NSCLC after disease progression on osimertinib: primary results from the phase III MARIPOSA-2 study. Ann Oncol 2024;35:77-90. [Crossref] [PubMed]
26. Fang W, Zhao Y, et al. Ivonescimab Plus Chemotherapy in Non-Small Cell Lung Cancer With EGFR Variant: A Randomized Clinical Trial. JAMA 2024;332:561-70.
27. Zhou C, Imamura F, Cheng Y, et al. Early clearance of plasma EGFR mutations as a predictor of response to osimertinib and comparator EGFR-TKIs in the FLAURA trial. J Clin Oncol 2019;37:9020.