Molecular heterogeneity and treatment outcome of EGFR exon 20 insertion mutations in Chinese patients with advanced non-small cell lung cancer: insights from a large-scale real-world study.

INTRODUCTION: This retrospective study aimed to investigate treatment patterns and outcomes in patients with NSCLC harboring EGFR20ins in China. EGFR20ins mutations are associated with poor responses to EGFR-TKIs, and limited real-world data exist regarding the efficacy of various treatment modalities. METHODS: In this retrospective, single-center study, treatment outcomes, including PFS and ORR, were evaluated for different treatment regimens based on imaging assessments. The impact of mutation heterogeneity on treatment efficacy was also explored. RESULTS: Data from 302 patients diagnosed with NSCLC with EGFR20ins were analyzed. EGFR-TKI monotherapy demonstrated suboptimal PFS compared to platinum-based chemotherapy in the first-line setting (3.00 m vs. 6.83 m, HR = 3.674, 95%CI = 2.48-5.44, p < 0.001). Platinum plus pemetrexed plus bevacizumab combination therapy showed improved PFS and ORR compared to platinum plus pemetrexed (7.50m vs. 5.43 m, HR = 0.593, 95%CI = 0.383-0.918, p = 0.019). In later-line treatments, monotherapy with EGFR-TKIs or ICIs exhibited suboptimal efficacy. The specific EGFR20ins subtype, A763_Y764insFQEA, showed favorable responses to EGFR-TKIs in real-world settings. CONCLUSIONS: This large-scale real-world study provides valuable insights into the treatment patterns and outcomes of NSCLC patients with EGFR20ins mutations in China. These findings contribute to the understanding of EGFR20ins treatment and provide real-world benchmark for future clinical trials and drug development.

A real-world cohort study of first-line afatinib in patients with EGFR-mutant advanced non-small cell lung cancer in Vietnam.

BACKGROUND: This study aimed to evaluate the efficacy and side effects of first-line afatinib treatment in a real-world setting in Vietnam. METHODS: This retrospective study was conducted across nine hospitals in Vietnam. Advanced epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) patients who received afatinib as first-line therapy between April 2018 and June 2022 were included, and patient medical records were reviewed. Key outcomes were overall response rate (ORR), time-to-treatment failure (TTF), and tolerability. RESULTS: A total of 343 patients on first-line afatinib were eligible for the study. EGFR exon 19 deletion (Del19) alone was detected in 46.9% of patients, L858R mutation alone in 26.3%, and other uncommon EGFR mutations, including compound mutations, in 26.8%. Patients with brain metastases at baseline were 25.4%. Patients who received 40 mg, 30 mg, and 20 mg as starting doses of afatinib were 58.6%, 39.9%, and 1.5%, respectively. The ORR was 78.1% in the overall population, 82.6% in the Del19 mutation subgroup, 73.3% in the L858R mutation subgroup, and 75.0% in the uncommon mutation subgroup (p > 0.05). The univariate and multivariate analyses indicate that the ORR increased when the starting dose was 40 mg compared to starting doses below 40 mg (83.9% vs. 74.3%, p = 0.034). The median TTF (mTTF) was 16.7 months (CI 95%: 14.8-18.5) in all patients, with a median follow-up time of 26.2 months. The mTTF was longer in patients in the common EGFR mutation subgroup (Del19/L858R) than in those in the uncommon mutation subgroup (17.5 vs. 13.8 months, p = 0.045) and in those without versus with brain metastases at baseline (17.5 vs. 15.1 months, p = 0.049). There were no significant differences in the mTTF between subgroups based on the starting dose of 40 mg and < 40 mg (16.7 vs. 16.9 months, p > 0.05). The most common treatment-related adverse events (any grade/grade ≥ 3) were diarrhea (55.4%/3.5%), rash (51.9%/3.2%), paronychia (35.3%/5.0%), and stomatitis (22.2%/1.2%). CONCLUSIONS: Afatinib demonstrated clinical effectiveness and good tolerability in Vietnamese EGFR-mutant NSCLC patients. In our real-world setting, administering a starting dose below 40 mg might result in a reduction in ORR; however, it might not have a significant impact on TTF.

Strong PD-L1 affect clinical outcomes in advanced NSCLC treated with third-generation EGFR-TKIs.

Background: In first/second generation EGFR-TKIs, strong PD-L1 expression contributes to primary resistance, significantly affecting patient prognosis. The relationship between PD-L1 expression levels and third-generation TKIs remains unclear.Methods: This study analyzed advanced NSCLC who received third-generation EGFR-TKIs as first-line systemic therapy from March 2019 to June 2022. The EGFR and PD-L1 status of the patients was also assessed.Results: Overall, 150 patients were included in this study. PD-L1 expression was negative (PD-L1 tumor proportion score <1%) in 89 cases, weak (1-49%) in 42 cases, and strong (≥50%) in 19 cases. mPFS for patients with negative, weak and strong PD-L1 expressions was 23.60, 26.12 and 16.60 months, respectively. The mPFS for strong PD-L1 expression was significantly shorter than that for with weak PD-L1 expression but was not associated with negativity. The same conclusions were shown in subgroup analyses of mutation types and TKI kinds. In addition, Relative to PD-L1-negative patients, resistance to TKIs may be associated with early progression for patients with strong PD-L1 expression.Conclusion: PD-L1 expression in tumor cells influenced the clinical outcomes of patients with advanced NSCLC treated with third-generation EGFR-TKIs. Stronger PD-L1 expression in TKIs-treated patients with advanced first-line EGFR-mutated NSCLC was associated with worse PFS.

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HER3 is widely expressed across diverse subtypes of NSCLC in a retrospective analysis of archived tissue samples.

Aim: This noninterventional study (NCT05769764) aimed to characterize human epidermal growth factor receptor 3 (HER3) expression in non-small cell lung cancer (NSCLC) by patient, clinical or tumor characteristics.Methods: HER3 immunohistochemistry was performed in archival tissue samples from patients with advanced or metastatic NSCLC. Samples were scored for membrane percent positivity and intensity. Membrane H-scores were calculated.Results: Of 203 evaluable samples, HER3 expression was observed in 98.5%, including all histologies, genomic subtypes and regardless of prior systemic anticancer treatments. The median H-score was 140, and 70.4% had a HER3 intensity of 3+.Conclusion: HER3 is widely expressed in NSCLC, indicating that HER3-directed therapy may be broadly applicable across diverse subtypes of NSCLC.

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Epidermal growth factor receptor-mutated lung carcinomas with insufficient response to epidermal growth factor receptor inhibitors.

Administration of single-agent epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) is a standard treatment option for metastatic non-small cell lung carcinomas with EGFR exon 19 deletions (ex19del) and L858R substitutions. However, there is a significant interpatient heterogeneity with regard to the degree of the response and its duration. Patients with EGFR ex19del mutation, TP53 wild-type, good performance status, low tumor burden and no circulating tumor DNA (ctDNA) at baseline have the best chances to derive pronounced benefit from TKI therapy. In contrast, subjects with EGFR L858R substitution, mutated TP53, poor overall condition, high tumor volume and detectable ctDNA are generally poor responders to EGFR inhibitors. ctDNA dynamics in the first days or weeks of treatment allows reliable identification of patients, who are very unlikely to derive clinically meaningful benefit from single-agent TKIs. These patients are candidates for clinical trials, which may involve the addition of chemotherapy and antiangiogenic drugs to patients, who failed to achieve immediate benefit from TKI monotherapy.

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Baseline genetic abnormalities and effectiveness of osimertinib treatment in patients with chemotherapy-naïve EGFR-mutated NSCLC based on performance status.

BACKGROUND/AIM: For patients treated with osimertinib as first-line therapy, there have been no studies comparing both progression-free survival (PFS) and overall survival (OS) according to performance status (PS). Furthermore, no studies have examined differences in baseline genetic abnormalities between patients with poor and good PS. Therefore, we aimed to investigate differences in baseline genetic abnormalities and treatment effects between patients with poor and good PS who received osimertinib as the primary treatment. PATIENTS AND METHODS: This is a secondary analysis of the ELUCIDATOR study, which is a multi-center prospective observational study in Japan that assessed mechanisms underlying resistance to osimertinib as first-line treatment for advanced non-small cell lung cancer with epidermal growth factor receptor mutations. RESULTS: There were 153 and 25 patients in the good and poor PS groups, respectively. Multivariate analysis revealed no significant between-group differences in PFS (hazards ratio [HR]: 0.98, 95% confidence interval [CI]: 0.52-1.72, p = 0.946). Multivariate analysis of OS revealed that poor PS was a poor prognostic factor (HR: 2.67, 95% CI: 1.43-4.73, p = 0.003). Regarding baseline genetic abnormalities, there was a significant increase in APC-positive cases (20.0% vs. 2.2%, p = 0.009) and a trend toward more CTNNB1-positive cases in the poor PS group than in the good PS group (14.3% vs. 2.9%, p = 0.062). CONCLUSION: There was no between-group difference in PFS, although OS was significantly inferior in the poor PS group. Additionally, there was a significant increase in APC-positive cases and a trend toward more CTNNB1-positive cases in the poor PS group.

The Impact of Inadequate Exposure to Epidermal Growth Factor Receptor-Tyrosine Kinase Inhibitors on the Development of Resistance in Non-Small-Cell Lung Cancer Cells.

Epidermal growth factor receptor (EGFR)-mutant non-small-cell lung cancer (NSCLC) patients treated with EGFR-tyrosine kinase inhibitors (TKIs) inevitably develop resistance through several biological mechanisms. However, little is known on the molecular mechanisms underlying acquired resistance to suboptimal EGFR-TKI doses, due to pharmacodynamics leading to inadequate drug exposure. To evaluate the effects of suboptimal EGFR-TKI exposure on resistance in NSCLC, we obtained HCC827 and PC9 cell lines resistant to suboptimal fixed and intermittent doses of gefitinib and compared them to cells exposed to higher doses of the drug. We analyzed the differences in terms of EGFR signaling activation and the expression of epithelial-mesenchymal transition (EMT) markers, whole transcriptomes byRNA sequencing, and cell motility. We observed that the exposure to low doses of gefitinib more frequently induced a partial EMT associated with an induced migratory ability, and an enhanced transcription of cancer stem cell markers, particularly in the HCC827 gefitinib-resistant cells. Finally, the HCC827 gefitinib-resistant cells showed increased secretion of the EMT inducer transforming growth factor (TGF)-ß1, whose inhibition was able to partially restore gefitinib sensitivity. These data provide evidence that different levels of exposure to EGFR-TKIs in tumor masses might promote different mechanisms of acquired resistance.

Dual kinase inhibitor for EGFR mutants and ErbB2 limit breast cancer.

Mutations in the epidermal growth factor receptor (EGFR) have been found in more than 10% of non-small cell lung cancer (NSCLC) patients in North America. The vast majority of these differences are L858R point mutations in Exon 21. Currently, monoclonal antibodies directed against the extracellular domain of EGFR or small molecule/tyrosine kinase inhibitors (TKI) are the stalwarts of NSCLC therapy. Resistance, however, gradually develops because of the T790 mutation towards first and second generation TKIs. The third generation TKI AZD9291 (Osimertinib) has a high affinity for both activating and the acquired resistant mutation (T790 M) in EGFR, with a low affinity towards wild-type EGFR. Recent research, however, suggests that the EGFR (C797S) mutation in the tyrosine kinase domain is a likely cause of resistance to AZD9291. Another significant transformation mechanism associated with this resistance is erbB2 amplification. Our laboratory has developed a small kinase inhibitor, ER121 (MW: ∼500), that inhibits the erbB2/HER2 tyrosine kinases in addition to the EGFR C797S mutations. We have identified a TKI, ER121 targeting the mutant EGFR(T790 M). Using in vitro and in vivo models, examined the efficacy of ER121 on mutant EGFR cell lines. This has enabled us to establish that ER121 is well tolerated when administered orally and produces significant inhibitory activity against human cancers generated by mutant EGFR and amplified ErbB2.

Rare mutation-dominant compound EGFR-positive NSCLC is associated with enriched kinase domain-resided variants of uncertain significance and poor clinical outcomes.

BACKGROUND: Compound epidermal growth factor receptor (EGFR) mutations are less responsive to tyrosine kinase inhibitors (TKIs) than single EGFR mutations in non-small cell lung cancer (NSCLC). However, the detailed clinical characteristics and prognosis of various compound EGFR mutations remain to be elucidated. METHODS: We retrospectively studied the next-generation sequencing (NGS) data of treatment-naïve tumors from 1025 NSCLC patients with compound EGFR mutations, which were sub-categorized into different combinations of common mutations (19-Del and EGFR exon 21 p.L858R), rare mutations, and variants of uncertain significance (VUSs). Prognosis and drug resistance to first-line TKIs were analyzed in 174 and 95 patients, respectively. RESULTS: Compound EGFR mutations were enriched with EGFR exon 21 p.L858R and rare mutations, but not 19-Del (P < 0.001). The common + rare and rare + rare subtypes had fewer concurrent mutations in the PI3K pathway (P = 0.032), while the rare + rare and common + VUSs subtypes showed increased association with smoking- and temozolomide-related mutational signatures, respectively (P < 0.001). The rare mutation-dominant subtypes (rare + VUSs and rare + rare) had the worst clinical outcomes to first-line TKIs (P < 0.001), which was further confirmed using an external cohort (P = 0.0066). VUSs in the rare + VUSs subtype selectively reside in the EGFR kinase domain (P < 0.001), implying these tumors might select additional mutations to disrupt the regulation/function of the kinase domain. CONCLUSIONS: Different subtypes of compound EGFR mutations displayed distinct clinical features and genetic architectures, and rare mutation-dominant compound EGFR mutations were associated with enriched kinase domain-resided VUSs and poor clinical outcomes. Our findings help better understand the oncogenesis of compound EGFR mutations and forecast prognostic outcomes of personalized treatments.

Common driver mutations and programmed death-ligand 1 expression in advanced non-small cell lung cancer in smokers and never smokers.

BACKGROUND: In non-small cell lung cancer (NSCLC), there may be a relationship between programmed death-ligand 1 (PD-L1) expression, driver mutations and cigarette smoking. METHODS: In this single-center retrospective study, the relationship between common driver mutations (EGFR mutation and ALK rearrangement) and PD-L1 expression in advanced NSCLC according to the patients' smoking history was examined. Light, moderate and heavy smokers had smoked < 20, 20-39, and ≥ 40 pack-years, respectively. The level of PD-L1 expression, assessed using Ventana SP263 monoclonal antibody assay, was defined by the tumor proportion score (TPS) as high expression (TPS ≥ 50%), low expression (TPS 1%-49%) and no expression (TPS < 1%). RESULTS: 101 (52.9%) of 191 advanced NSCLC patients were never smokers. EGFR mutations were more common in never smokers (64.4%) than in smokers (17.8%) with advanced NSCLC (P < 0.0001). A higher proportion of smokers (26.7%) had high PD-L1 expression compared to never smokers (13.9%) (P = 0.042). There was a trend for a higher proportion of male NSCLC patients [28 of 115 (24.3%)] than female patients [10 of 76 (13.2%)] to have high PD-L1 expression (P = 0.087]. High PD-L1 expression was seen in 32 of 110 (29.1%) patients with EGFR wild-type NSCLC but only in 6 of 81 (7.4%) patients with EGFR-mutant tumors (P < 0.0001). Among the 90 smokers with NSCLC, a higher proportion of heavy smokers (35.8%) than non-heavy smokers (13.5%) had high PD-L1 expression (P = 0.034). In patients with adenocarcinoma, high PD-L1 expression was seen in 25 of 77 (32.5%) patients with EGFR wild-type tumors but only in 4 of 70 (5.7%) patients with EGFR-mutant tumors (P < 0.0001). Among patients with adenocarcinoma, a significantly higher proportion of ever smokers (29.3%) than never smokers (13.5%) had high PD-L1 expression (P = 0.032). Among smokers with adenocarcinoma, a significantly higher proportion of heavy smokers (44.1%) than non-heavy smokers (8.3%) had high PD-L1 expression (P = 0.004). On multivariate analysis, after adjusting for gender and smoking status, heavy smoking and EGFR wild-type tumors remained significantly associated with high PD-L1 expression in NSCLCs and also in adenocarcinoma. CONCLUSIONS: Heavy smoking and EGFR wild-type tumors were significantly associated with high PD-L1 expression in NSCLCs and also in adenocarcinoma.

Discovery of mobocertinib, a potent, oral inhibitor of EGFR exon 20 insertion mutations in non-small cell lung cancer.

In the treatment of non-small cell lung cancer (NSCLC), patients harboring exon 20 insertion mutations in the epidermal growth factor receptor (EGFR) gene (EGFR) have few effective therapies because this subset of mutants is generally resistant to most currently approved EGFR inhibitors. This report describes the structure-guided design of a novel series of potent, irreversible inhibitors of EGFR exon 20 insertion mutations, including the V769_D770insASV and D770_N771insSVD mutants. Extensive structure-activity relationship (SAR) studies led to the discovery of mobocertinib (compound 21c), which inhibited growth of Ba/F3 cells expressing the ASV insertion with a half-maximal inhibitory concentration of 11 nM and with selectivity over wild-type EGFR. Daily oral administration of mobocertinib induced tumor regression in a Ba/F3 ASV xenograft mouse model at well-tolerated doses. Mobocertinib was approved in September 2021 for the treatment of adult patients with advanced NSCLC with EGFR exon 20 insertion mutations with progression on or after platinum-based chemotherapy.

Synthesis and evaluation of sulfonamide derivatives targeting EGFR790M/L858R mutations and ALK rearrangement as anticancer agents.

Fourteen new compounds bearing sulfonamide groups that target EGFRT790M/L858R mutations and ALK rearrangement were synthesized and evaluated as dual-target tumor inhibitors. The study on the anti-proliferation activity on cancer cells showed that the sulfonamide derivative with pyrimidine nucleus had much better activities compared with those with quinazoline nucleus. Among them, compound 19e exhibited excellent activity against H1975 cancer cell lines (EGFRT790M/L858R high express) and H2228 cells (ALK rearrangement) with the IC50 values of 0.0215 µM and 0.011 µM, respectively. The ALK and EGFR kinase inhibition assays also provided similar results. Genotype selectivity of EGFR on kinase and cell level, cytotoxicity towards human normal cell lines and cell morphology assay implied that 19e had acceptable selectivity and low toxicity. In addition, the inhibitory activity of 19e on H1975 and H2228 cells cloning and its apoptosis-inducing effect on the two cell lines were studied, and its inhibitory effect on the invasion and migration of tumor cells were also investigated. All the results show that 19e is worthy of further study.

Design, synthesis, and biological evaluation of pyrido[2,3-d]pyrimidine and thieno[2,3-d]pyrimidine derivatives as novel EGFRL858R/T790M inhibitors.

EGFR mutations have been identified in 20,000 reported NSCLC (non-small cell lung cancer) samples, and exon 19 deletions and L858R mutations at position 21, known as "classical" mutations, account for 85-90% of the total EGFR (epidermal growth factor receptor) mutations. In this paper, two series of EGFR kinase inhibitors were designed and synthesised. Among them, compound B1 showed an IC50 value of 13 nM for kinase inhibitory activity against EGFRL858R/T790M and more than 76-fold selectivity for EGFRWT. Furthermore, in an in vitro anti-tumour activity test, compound B1 showed an effective anti-proliferation activity against H1975 cells with an IC50 value of 0.087 µΜ. We also verified the mechanism of action of compound B1 as a selective inhibitor of EGFRL858R/T790M by cell migration assay and apoptosis assay.

Tyrosine Kinase Inhibitor Activity in Patients with NSCLC Harboring Uncommon EGFR Mutations: A Retrospective International Cohort Study (UpSwinG).

BACKGROUND: Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs) are standard of care for patients with EGFR mutation-positive non-small-cell lung cancer (NSCLC) with common mutations (Del19 or L858R); however, 7%-23% of NSCLC tumors harbor uncommon EGFR mutations. These mutations are highly heterogeneous, and developments in detection techniques are helping to identify mutations with little or no clinical data. PATIENTS AND METHODS: In this retrospective, global, multi-center study (NCT04179890), existing health records were identified for consecutive EGFR TKI-naïve patients with uncommon EGFR mutations (T790M, ex20ins, major uncommon [G719X, L861Q, or S768I], or "other" mutations; compound mutations) treated with erlotinib, gefitinib, afatinib, or osimertinib in first or second line. Endpoints included time-to-treatment failure (TTF), objective response rate (ORR), and overall survival (OS). RESULTS: Overall, 246 patients (median age: 69.5 years; Asian: 84%) were included from 9 countries. Most patients (92%) received an EGFR TKI as first-line therapy; 54%, 43% and 3% received afatinib, first-generation TKIs, and osimertinib, respectively. Median TTF and OS with EGFR TKIs were 9.9 and 24.4 months; ORR was 43%. In patients treated with first-line chemotherapy (n = 20), median TTF and ORR were 6.6 months and 41%. Outcomes were most favorable in patients with major uncommon or compound mutations. Overall, TTF was 11.3 months with afatinib and 8.8 months with first-generation EGFR TKIs across mutation categories. In most mutation categories, median OS was >2 years. CONCLUSION: In a real-world setting, EGFR TKIs were the preferred treatment option in patients with uncommon EGFR mutations; strongest outcomes were seen in patients with major uncommon and compound mutations.

A randomised phase II study of osimertinib and bevacizumab versus osimertinib alone as second-line targeted treatment in advanced NSCLC with confirmed EGFR and acquired T790M mutations: the European Thoracic Oncology Platform (ETOP 10-16) BOOSTER trial.

BACKGROUND: While osimertinib, a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) is the standard treatment in patients with advanced non-small-cell lung cancer (NSCLC) with sensitising EGFR and acquired T790M mutations, progression inevitably occurs. The angiogenic pathway is implicated in EGFR TKI resistance. PATIENTS AND METHODS: BOOSTER is an open-label randomised phase II trial investigating the efficacy and safety of combined osimertinib 80 mg daily and bevacizumab 15 mg/kg every 3 weeks, versus osimertinib alone, in patients with EGFR-mutant advanced NSCLC and acquired T790M mutations after failure on previous EGFR TKI therapy. Primary endpoint was investigator-assessed progression-free survival (PFS). Secondary endpoints were overall survival (OS), objective response rate (ORR) and adverse events (AEs). RESULTS: Between May 2017 and February 2019, 155 patients were randomised (combination: 78; osimertinib: 77). At data cut-off of 22 February 2021, median follow-up was 33.8 months [interquartile range (IQR): 26.5-37.6 months] and 129 (83.2%) PFS events were reported in the intention-to-treat population. There was no difference in median PFS between the combination [15.4 months; 95% confidence interval (CI) 9.2-18.0 months] and osimertinib arm (12.3 months; 95% CI 6.2-17.2 months; stratified log-rank P = 0.83), [hazard ratio (HR) = 0.96; 95% CI 0.68-1.37]. Median OS was 24.0 months (95% CI 17.8-32.1 months) in the combination arm and 24.3 months (95% CI 16.9-37.0 months) in the osimertinib arm (stratified log-rank P = 0.91), (HR = 1.03; 95% CI 0.67-1.56). Exploratory analysis revealed a significant interaction of smoking history with treatment for PFS (adjusted P = 0.0052) with a HR of 0.52 (95% CI 0.30-0.90) for smokers, and 1.47 (95% CI 0.92-2.33) for never smokers. ORR was 55% in both arms and the median time to treatment failure was significantly shorter in the combination than in the osimertinib arm, 8.2 months versus 10.8 months, respectively (P = 0.0074). Safety of osimertinib and bevacizumab was consistent with previous reports with grade ≥3 treatment-related AEs (TRAEs) reported in 47% and 18% of patients on combination and osimertinib alone, respectively. CONCLUSIONS: No difference in PFS was observed between osimertinib plus bevacizumab and osimertinib alone. Grade ≥3 TRAEs were more common in patients on combination.

Treatment outcome of atypical EGFR mutations in the German National Network Genomic Medicine Lung Cancer (nNGM).

BACKGROUND: Atypical EGFR mutations occur in 10%-30% of non-small-cell lung cancer (NSCLC) patients with EGFR mutations and their sensitivity to classical epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKI) is highly heterogeneous. Patients harboring one group of uncommon, recurrent EGFR mutations (G719X, S768I, L861Q) respond to EGFR-TKI. Exon 20 insertions are mostly insensitive to EGFR-TKI but display sensitivity to exon 20 inhibitors. Clinical outcome data of patients with very rare point and compound mutations upon systemic treatments are still sparse to date. PATIENTS AND METHODS: In this retrospective, multicenter study of the national Network Genomic Medicine (nNGM) in Germany, 856 NSCLC cases with atypical EGFR mutations including co-occurring mutations were reported from 12 centers. Clinical follow-up data after treatment with different EGFR-TKIs, chemotherapy and immune checkpoint inhibitors were available from 260 patients. Response to treatment was analyzed in three major groups: (i) uncommon mutations (G719X, S7681, L861Q and combinations), (ii) exon 20 insertions and (iii) very rare EGFR mutations (very rare single point mutations, compound mutations, exon 18 deletions, exon 19 insertions). RESULTS: Our study comprises the largest thus far reported real-world cohort of very rare EGFR single point and compound mutations treated with different systemic treatments. We validated higher efficacy of EGFR-TKI in comparison to chemotherapy in group 1 (uncommon), while most exon 20 insertions (group 2) were not EGFR-TKI responsive. In addition, we found TKI sensitivity of very rare point mutations (group 3) and of complex EGFR mutations containing exon 19 deletions or L858R mutations independent of the combination partner. Notably, treatment responses in group 3 (very rare) were highly heterogeneous. Co-occurring TP53 mutations exerted a non-significant trend for a detrimental effect on outcome in EGFR-TKI-treated patients in groups 2 and 3 but not in group 1. CONCLUSIONS: Based on our findings, we propose a novel nNGM classification of atypical EGFR mutations.

Clinical outcomes of advanced non-small cell lung cancer patients harboring distinct subtypes of EGFR mutations and receiving first-line tyrosine kinase inhibitors: brain metastasis and de novo T790M matters.

BACKGROUND: The clinical features, survival outcomes and patterns of treatment failure of advanced non-small cell lung cancer (NSCLC) patients harboring distinct subtypes of EGFR mutations and receiving first-line EGFR tyrosine kinases inhibitor (TKIs) are not fully understood. METHODS: Consecutive metastatic EGFR-mutant NSCLC patients receiving first-line EGFR-TKIs from October 2010 to March 2020 were enrolled and classified into two main groups based on the EGFR mutation subtypes: common mutation (L858R or exon 19 deletion), uncommon mutation (other EGFR mutations). RESULTS: Of the 1081 patients included, 74 (6.8%) harbored uncommon mutations. The baseline characteristics were generally balanced between the two groups, except that bone metastasis developed less frequently in patients with uncommon mutations (p = 0.02). No significant difference of survival outcomes was found between the two groups, except that among patients with baseline brain metastasis, the intracranial time to progression was significantly shorter in patients with uncommon mutations. Nine of the 17 patients with de novo T790M mutation received Osimertinib, whose overall survival tended to be longer than the remaining 8 patients without Osimertinib treatment (p = 0.08). The patterns of treatment failure were generally consistent between the two groups, except which patients with uncommon mutations had a higher risk developing progressive disease in the brain. CONCLUSION: First-line EGFR-TKIs seemed to be less effective in controlling and preventing brain metastasis in patients with uncommon EGFR mutations and Osimertinib was associated with promising efficacy in patients with de novo T790M mutation, which warranted further validation.

Correlation of Epidermal Growth Factor Receptor Mutation With Major Histologic Subtype of Lung Adenocarcinoma According to IASLC/ATS/ERS Classification.

OBJECTIVE: Our prospective study aims to define the correlation of EGFR(epidermal growth factor receptor) mutations with major histological subtypes of lung adenocarcinoma from resected and non-resected specimens, according to the WHO 2015 classification, in Moroccan North East Population. METHODS: Epidermal growth factor receptor mutations of 150 primary lung adenocarcinoma were performed using Real-Time PCR or SANGER sequencing. SPSS 21 was used to assess the relationship between histological subtypes of lung adenocarcinoma and EGFR mutation status. RESULTS: 25 mutations were detected in the series of 150 lung adenocarcinomas, most of which were found in cases with papillary, acinar, patterns than without these patterns and more frequently occurred in the cases without solid pattern than with this pattern. A significant correlation was observed between EGFR mutation and acinar (P = 0,024), papillary pattern (P = 0,003) and, negative association with a solid pattern (P < 0,001). In females, EGFR mutations were significantly correlated with the acinar pattern (P = 0,02), whereas in males with the papillary pattern (P = 0,01). Association between the histologic component and exon 19 deletions and exon 21 mutations were also evaluated and, we found a significant correlation between the papillary major pattern with exon 19 mutations (P = 0,004) and, ex21 with the acinar component (P = 0,03). CONCLUSION: An analysis of resected and non-resected lung ADC specimens in 150 Moroccan Northeast patients, revealed that acinar and papillary patterns may predict the presence of a mutation in the EGFR gene. While the solid major pattern may indicate a low mutation rate of the EGFR gene.

MARIPOSA: phase 3 study of first-line amivantamab + lazertinib versus osimertinib in EGFR-mutant non-small-cell lung cancer.

Third-generation EGFR tyrosine kinase inhibitors (TKIs), such as osimertinib, have demonstrated efficacy in patients with EGFR-mutant non-small-cell lung cancer; however, almost all patients will eventually relapse. Amivantamab is an EGFR-MET bispecific antibody with immune cell-directing activity that targets activating and resistance EGFR mutations and MET mutations and amplifications. In the ongoing CHRYSALIS study (NCT02609776), amivantamab in combination with lazertinib, a potent, brain-penetrant third-generation EGFR TKI, demonstrated antitumor activity in the treatment-naive and osimertinib-relapsed setting. Here the authors present the methodology for the MARIPOSA study (NCT04487080), a phase 3, multicenter, randomized study designed to compare the efficacy and safety of amivantamab and lazertinib combination therapy versus single-agent osimertinib as first-line treatment for EGFR-mutant non-small-cell lung cancer.

Plain language summary Osimertinib is the standard-of-care treatment for patients with non-small-cell lung cancer caused by mutations in the EGFR. However, patients will eventually see their disease return because their tumors will develop new mutations that are resistant to osimertinib treatment. Amivantamab is a new antibody treatment that blocks the EGFR and another receptor called the MET receptor, to stop the growth of lung tumor cells. In an ongoing clinical trial, called the CHRYSALIS study, when amivantamab was given with lazertinib (another drug that blocks the EGFR), lung tumors shrank in patients whose lung cancer had not been previously treated. A new clinical trial called the MARIPOSA study (NCT04487080) aims to compare the antitumor activity and safety of the amivantamab + lazertinib combination versus osimertinib alone in patients with EGFR-mutant non-small-cell lung cancer who have not received treatment for their lung cancer. Trial registration number: NCT04487080 (ClinicalTrials.gov).

Uncommon EGFR mutations conducted with osimertinib in patients with NSCLC: a study protocol of phase 2 study (UNICORN/TCOG1901).

Patients with uncommon EGFR-mutated non-small-cell lung cancer (NSCLC) demonstrated lower clinical efficacy of first-generation EGFR-tyrosine kinase inhibitors compared with patients harboring common EGFR-mutated NSCLC. The US FDA has approved afatinib for uncommon EGFR mutation positive NSCLC based on the pooled analysis in the first- or second-line setting. Osimertinib has limited evidence in the small sample sizes of phase 2 studies in any-line settings. The aim of the present single-arm, multicenter, phase 2 study is to evaluate the efficacy of osimertinib for previously untreated NSCLC. The primary end point is to assess the overall response to osimertinib. The secondary end points include disease control rate, progression-free survival, duration of time-to-treatment failure, overall survival and safety. Clinical trial registration: jRCTs071200002.

Lay abstract Tyrosine kinase inhibitor (TKI) medications are targeting EGFR work on the first-line treatment for patients with common EGFR mutation positive non-small-cell lung cancer (EGFR+ NSCLC) that has spread to other parts of the body and has the EGFR+ NSCLC in tumor testing. Uncommon EGFR mutations and compound EGFR mutations have less activity for first-generation EGFR-TKIs; however, second- or third-generation EGFR-TKIs are broader spectrum than first-generation EGFR-TKIs have activities ideally. The authors describe the need for and design a study of osimertinib in patients with uncommon/compound EGFR+ NSCLC.