Atypical L858R or other L858X mutations in the epidermal growth factor receptor (EGFR) gene, beyond the classical EGFRL858R mutation caused by c.2573 T > G, have been identified in non-small cell lung cancer (NSCLC), yet their genomic features and survival benefits with EGFR tyrosine kinase inhibitor (TKI) treatment have not been fully explored. We retrospectively enrolled 489 NSCLC patients with baseline tumor tissue/plasma samples carrying uncommon EGFRL858R (N = 124), EGFRL858Q/M (N = 17), or classical EGFRL858R mutations (N = 348). The comparison of molecular features was performed using treatment-naïve tumor tissues. Survival benefits and resistance mechanisms of first-line EGFR TKI treatment were studied in an advanced disease subcohort. NSCLCs harboring uncommon EGFRL858R had lower TP53 mutation prevalence (p = 0.04) and chromosome instability scores (p = 0.02) than those with classical EGFRL858R. Concomitant EGFRL861Q mutations were enriched in NSCLCs with EGFRL858Q/M (p < 0.01), with cooccurrence in those carrying EGFRL858M. Patients with uncommon EGFRL858R experienced improved progression-free survival (PFS) compared to those with classical EGFRL858R (median: 13.0 vs. 10.0 months, hazard ratio [HR]: 0.57, 95% confidence interval [CI]: 0.41-0.80). The association remained significant when adjusting for sex, age, histological subtype, TKI category, and anti-vascular therapy (HR: 0.55, 95% CI: 0.39-0.77). Furthermore, EGFRL858Q/M patients showed enhanced first-line PFS (vs. classical EGFRL858R, HR: 0.26, 95% CI: 0.10-0.67), potentially benefiting more from afatinib. Additionally, NSCLCs with uncommon EGFRL858R and classical EGFRL858R had similar resistance profiles to EGFR TKIs. In conclusion, NSCLCs carrying atypical EGFR L858 aberrations, which had fewer TP53 mutations and higher chromosome stability, exhibited improved PFS under first-line EGFR TKIs than those with the classical EGFRL858R.

Sutetinib is an irreversible inhibitor of epidermal growth factor receptor (EGFR) and showed favorable efficacy and safety in patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) harbouring nondrug-resistant rare EGFR mutations. To evaluate the potential food effect, eighteen healthy Chinese subjects were enrolled in a single-centre, randomized, open-label, two-sequence, two-period crossover study. Sutetinib was administered as a single oral 100 mg under fasting or fed conditions, and pharmacokinetic sampling was performed following each dose and analysed by a validated liquid chromatography/mass spectrometry method. Safety and tolerability were also evaluated. Food intake slightly decreased maximum plasma concentration (Cmax) and area under the plasma concentration-time curve from time 0 to infinity (AUC0 - inf) of sutetinib (geometric least-squares mean [GLSM] ratio, 80.94% and 86.11%; 90% confidence interval [CI], 68.43-95.72 and 75.88-97.73) and its active metabolite sutetinib N-Oxide (GLSM ratio, 75.58% and 84.00%; 90% CI, 65.69-86.95 and 75.42-93.56), respectively. In addition, the time to maximum plasma concentration (Tmax) of both sutetinib and its metabolite has been prolonged by 2 h under fed conditions. A total of 31 adverse events (AEs) occurred during the study, with no serious adverse events (SAE) reported, and no obvious difference was observed between the fasting and fed groups. Our results demonstrated that a high-fat and high-calorie diet caused a significant delay in drug absorption and a marginal reduction in drug exposure. Sutetinib was generally well tolerated in healthy Chinese subjects. (This trial was registered at http://www.chinadrugtrials.org.cn . The registration No. is CTR20201933, and the date of registration is 2020-10-16).

Background: The treatment paradigm for advanced non-small-cell lung cancer (NSCLC) is rapidly changing. Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) and anti-programmed death-1 (PD-1) antibodies have increasingly been incorporated into routine care for nearly all patients with NSCLC. Toripalimab was recently approved as the first-line treatment for advanced non-squamous NSCLC in combination with chemotherapy. Stevens-Johnson syndrome (SJS) is a rare but potentially fatal complication of TKI and anti-PD-1 therapy. We reported a case of SJS after sequential use of EGFR-TKIs and toripalimab in an NSCLC patient with EGFR mutations 19 del/T790M/C797S in trans and cis. Case presentation: A 58-year-old man with stage IV NSCLC received gefitinib because next-generation sequencing (NGS) revealed an EGFR 19del, followed by osimertinib and pemetrexed with the emergence of EGFR T790M. Four EGFR mutations 19 del/T790M/C797S in trans and cis were detected after osimertinib resistance. The combination of toripalimab and docetaxel was administered as a third-line treatment. The patient developed SJS at 21 days, and toripalimab was discontinued. After treatment with methylprednisolone and prednisolone, the skin toxicity of the patient gradually decreased and eventually disappeared. The patient received osimertinib and anlotinib after recovery, and SJS has not recurred. The ongoing treatment is still effective and results in stable disease. Conclusion: We reported the first case of SJS induced by toripalimab in a patient with lung adenocarcinoma harboring multiple EGFR mutations. The TKI treatment after SJS was well tolerated and effective.

BACKGROUND: The absence of thyroid transcription factor 1 (TTF-1) is associated with a lower frequency of epidermal growth factor receptor (EGFR) mutations in lung adenocarcinoma (LUAD). The aim of this study was to assess the impact of TTF-1 expression on the clinical response to EGFR-tyrosine kinase inhibitor (TKI) treatment in patients with advanced LUAD.
METHODS: The data of patients with advanced LUAD who were admitted to the Beijing Tiantan Hospital and Peking University Cancer Hospital (China) between April 2009 and May 2023 was retrospectively analyzed.
RESULTS: A total of 227 patients diagnosed with advanced LUAD were included, of which 28.2% (64/227) had TTF-1-negative adenocarcinoma, while 54.6% (124/227) harbored EGFR mutations. Negative TTF-1 expression significantly correlated with male sex (68.8% vs. 42.3%, p < 0.001), history of heavy smoking (57.8% vs. 36.2%, p = 0.003), poorly differentiated tumors (86.5% vs. 43.2%, p < 0.001), and lower frequency of EGFR mutations (26.6% vs. 65.6%, p < 0.001) compared with TTF-1 positivity. Multivariable logistic regression showed that low prevalence of EGFR mutations (p < 0.001) and male sex (p = 0.006) were independent predictive factors for the negative expression of TTF-1. Patients lacking TTF-1 also exhibited worse overall response rate (ORR; 23.5% vs. 54.2%, p = 0.019), disease control rate (DCR; 58.8% vs. 89.7%, p = 0.003), and median progression-free survival (PFS; 2.9 vs. 11.6 months, p < 0.001) following treatment with EGFR-TKIs compared to the TTF-1-positive patients with EGFR mutations.
CONCLUSIONS: Patients with TTF-1-negative and EGFR-mutant LUAD show a diminished response to EGFR-TKIs.

Uncommon epidermal growth factor receptor (EGFR) mutations account for 10%-20% of all EGFR mutations in non-small-cell lung cancer (NSCLC). The uncommon EGFR-mutated NSCLC is associated with poor clinical outcomes and generally achieved unsatisfactory effects to the current therapies using standard EGFR-tyrosine kinase inhibitors (TKIs), including afatinib and osimertinib. Therefore, it is necessary to develop more novel EGFR-TKIs to treat uncommon EGFR-mutated NSCLC. Aumolertinib is a third-generation EGFR-TKI approved in China for treating advanced NSCLC with common EGFR mutations. However, it remains unclear whether aumolertinib is effective in uncommon EGFR-mutated NSCLC. In this work, the in vitro anticancer activity of aumolertinib was investigated in engineered Ba/F3 cells and patient-derived cells bearing diverse uncommon EGFR mutations. Aumolertinib was shown to be more potent in inhibiting the viability of various uncommon EGFR-mutated cell lines than those with wild-type EGFR. And in vivo, aumolertinib could also significantly inhibit tumor growth in two mouse allograft models (V769-D770insASV and L861Q mutations) and a patient-derived xenografts model (H773-V774insNPH mutation). Importantly, aumolertinib exerts responses against tumors in advanced NSCLC patients with uncommon EGFR mutations. These results suggest that aumolertinib has the potential as a promising therapeutic candidate for the treatment of uncommon EGFR-mutated NSCLC.

EGFR-TKI is widely used for EGFR-mutant NSCLC patients. Bleeding is reported as a neglected adverse effect induced by EGFR-TKI. Female patients with lung adenocarcinoma have a high frequency of EGFR mutations. This study investigated the effect of EGFR-TKI on the menstrual cycle, especially on bleeding, in women of childbearing age. The underlying mechanism was further investigated in a patient with severe bleeding. We retrospectively investigated the effects on menstrual cycle in premenopausal female NSCLC patients who underwent EGFR-TKI treatment during 2013 to 2019. Menstrual changes including cycle disorders and prolonged bleeding were investigated via questionnaire survey. EGFR signaling, ER, PR and tissue factor expression were analyzed in endometrium tissue obtained from a 43-year-old patient who suffered from continuous vaginal bleeding during treatment with erlotinib and osimertinib. Among 42 premenopausal female patients taking EGFR tyrosine kinase inhibitor, 69.05% patients experienced abnormal menstruation. In women with abnormal menstruation, 41.37% had profuse menstruation and 20.69% had irregular menstruation. In most cases, the abnormal vaginal bleeding stopped when suspending EGFR-TKI. The EGFR-TKI induced abnormal vaginal bleeding might be associated with low progesterone level, decreased EGFR activation and tissue factor (TF) expression in endometrial tissues. EGFR-TKI unusually induce abnormal vaginal bleeding in premenopausal female NSCLC patients, which may be attributed to progesterone/EGFR/TF signaling. Megestrol acetate may be an available and effective drug for the uncommon adverse effect.

BACKGROUND: EGFR tyrosine kinase inhibitor (TKI) is recommended as the first-line therapy for patients with EGFR-mutant metastatic non-small cell lung cancer (NSCLC). Yet, resistance often occurs in 1 year after therapy and most progressions occur at the initial sites of disease. Addition of local therapy to the first-line TKI therapy may delay the progression and provide survival benefit to the patients.
METHODS: From 2010 to 2017, metastatic NSCLC patients with EGFR activating mutations who received first-line TKI and relatively radical local therapy (RRLT) were reviewed. RRLT was defined as local curative therapy to the main site or any intensity of local therapy to all sites of disease. The Kaplan-Meier method and log-rank test were used for survival estimation and comparison.
RESULTS: A total of 45 patients were included in this retrospective study with a median follow-up of 48.0 months. The median progression-free survival (PFS) and overall survival (OS) was 17.0 months (95% confidence interval [CI]: 14.6-19.3) and 55.0 months (95% CI: 49.3-60.6), respectively. Univariate analysis indicated that age ⩽ 60 years (P = .019), first-line TKI duration ⩾ 10 months (P = .028), and accumulated TKI duration ⩾ 20 months (P = .016) were significantly associated with favorable OS. Among the 36 patients who progressed during the follow-up, 55.8% of the progressions occurred at the new sites. RRLT combined with TKI did not show any severe toxicity to the patients.
CONCLUSIONS: Combined application of RRLT and first-line TKI may improve the survival and alter the pattern of failure for metastatic NSCLC patients with EGFR activating mutations.

Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are currently considered as the standard therapy for patients with advanced non-small cell lung cancer (NSCLC) who have EGFR-activating mutations. However, despite an initially profound response to these drugs, these patients ultimately develop drug resistance. The most common resistance mechanism is the development of a secondary mutation in EGFR (T790M), although activation of the MNNG/HOS transforming gene (MET), amplification of the Erb-B2 receptor tyrosine kinase 2 gene and histological transformation to small cell lung cancer may also lead to resistance. In addition, there may be additional, rare mechanisms leading to resistance that remain unidentified. Mutations in the EGFR kinase domain duplication (EGFR-KDD) are rare, although they act as oncogenic drivers in NSCLC. To the best of our knowledge, all studies to date have reported EGFR-KDD as the primary mutation in NSCLC. The aim of the present study was to report the case of an EGFR-KDD mutation in a patient with NSCLC who developed acquired resistance to gefitinib, but responded well to afatinib. Therefore, EGFR-KDD mutation is an additional potential mechanism underlying the development of acquired resistance to EGFR-TKIs.

UNASSIGNED: Insulin-like growth factor signaling has been implicated in acquired resistance to EGFR tyrosine kinase inhibitors (TKIs) in NSCLC. This phase 1 trial (NCT02191891) investigated the combination of xentuzumab (an insulin-like growth factor-ligand neutralizing monoclonal antibody) and afatinib (an EGFR TKI) in patients with previously treated EGFR mutation-positive NSCLC.
UNASSIGNED: The trial comprised dose escalation (part A) and expansion (part B). Patients had advanced or metastatic NSCLC that had progressed on EGFR TKI monotherapy or platinum-based chemotherapy (nonadenocarcinoma only, part A) or irreversible EGFR TKI monotherapy (part B). Absence of EGFR T790M mutation was required in part B. Part A used a 3 + 3 design, with a starting dose of xentuzumab 1000 mg/wk (intravenous) and afatinib 30 mg/d (oral). Primary endpoints were the maximum tolerated dose of the combination (part A) and objective response (part B).
UNASSIGNED: A total of 16 patients each were treated in parts A and B. Maximum tolerated dose was xentuzumab 1000 mg/wk plus afatinib 40 mg/d. No patients in part B had an objective response, but 10 had stable disease (median [range] duration of disease control: 2.3 [0.8-10.9] mo). The most common drug-related adverse events were diarrhea (75 %), paronychia (69 %), and rash (69 %) in part A and diarrhea (31 %), rash (19 %), paronychia (19 %), and fatigue (19 %) in part B.
UNASSIGNED: There were no new safety issues; xentuzumab and afatinib could be safely coadministered. Nevertheless, the combination revealed only modest activity in patients with EGFR mutation-positive, T790M-negative NSCLC after progression on afatinib.

BACKGROUND: The TIGER-3 (NCT02322281) study was initiated to compare the efficacy and safety of rociletinib, a third-generation EGFR tyrosine kinase inhibitor (TKI) that targets EGFR T790M and common EGFR-activating mutations, versus chemotherapy in patients with NSCLC who progressed on first- or second-generation EGFR TKIs.
METHODS: Patients with advanced or metastatic EGFR-mutated NSCLC with disease progression on standard therapy (previous EGFR TKI and platinum-based chemotherapy) were randomized to oral rociletinib (500 or 625 mg twice daily) or single-agent chemotherapy (pemetrexed, gemcitabine, docetaxel, or paclitaxel).
RESULTS: Enrollment was halted when rociletinib development was discontinued in 2016. Of 149 enrolled patients, 75 were randomized to rociletinib (n = 53: 500 mg twice daily; n = 22: 625 mg twice daily) and 74 to chemotherapy. The median investigator-assessed progression-free survival (PFS) was 4.1 months (95% confidence interval [CI]: 2.6-5.4) in the rociletinib 500-mg group and 5.5 months (95% CI: 1.8-8.1) in the 625-mg group versus 2.5 months (95% CI: 1.4-2.9) in the chemotherapy group. An improved PFS was observed in patients with T790M-positive NSCLC treated with rociletinib (n = 25; 500 mg and 625 mg twice daily) versus chemotherapy (n = 20; 6.8 versus 2.7 mo; hazard ratio = 0.55, 95% CI: 0.28-1.07, p = 0.074). Grade 3 or higher hyperglycemia (24.0%), corrected QT prolongation (6.7%), diarrhea (2.7%), and vomiting (1.3%) were more frequent with rociletinib than chemotherapy (0%, 0%, 1.4%, and 0%, respectively).
CONCLUSIONS: Rociletinib had a more favorable median PFS versus chemotherapy but had higher rates of hyperglycemia and corrected QT prolongation in patients with advanced EGFR-mutated NSCLC who progressed on previous EGFR TKI. Incomplete enrollment prevented evaluation of the primary efficacy end point.