OUP accepted manuscript

Osimertinib in uncommon EGFR exon 21 L861R and EGFR exon 18 deletion-insertion mutant non-small cell lung cancer-case report

Background

Tyrosine kinase inhibitors (TKIs) have changed the treatment landscape for patients with advanced non-small cell lung cancer (NSCLC) found to have oncogene-driven activating epidermal growth factor receptor (EGFR) mutations. Whilst there have been a handful of case reports of sensitivity to first-generation TKIs in EGFR L861R mutations, the efficacy of the third-generation TKI osimertinib in NSCLC patients with EGFR L861R and EGFR exon 18 deletion-insertion mutations is limited.

Case Description

We report two patients from our institution with uncommon EGFR mutations treated with first-line osimertinib. Our first patient, a 72-year-old male with metastatic lung adenocarcinoma was identified to harbour a rare EGFR L861R mutation and was commenced on osimertinib. After a follow-up period of 18 months, the patient is continuing to experience treatment benefit with imaging showing a good partial response. The second patient, a 60-year-old male also with metastatic lung adenocarcinoma and an EGFR exon 18 deletion-insertion mutation achieved a partial response for 6.6 months. Upon progression, he was commenced on carboplatin and pemetrexed chemotherapy however died from subsequent pneumonia. He had an overall survival (OS) from time of diagnosis of 7.6 months.

Conclusions

We demonstrate clinical efficacy of first-line osimertinib in the treatment of advanced NSCLC harbouring uncommon EGFR L861R and EGFR exon 18 deletion-insertion mutations. These results may be suggestive of the wider applicability of osimertinib in the treatment of uncommon EGFR mutant NSCLC.

A case report of a lung cancer patient with two uncommon EGFR mutations and a review of the literature: two sides of the same coin

Lung cancer is the malignancy with the highest morbidity and mortality worldwide. Approximately 60% of non-small cell lung cancer (NSCLC) presents driver alterations most of which are targetable. Nowadays, limited clinical data are available regarding the efficacy of epithelial growth factor receptor (EGFR) tyrosine kinase inhibitors in patients with NSCLC harboring uncommon EGFR mutations, considering their heterogeneity. Herein, we report a rare case of EGFR-mutated lung adenocarcinoma which has developed into squamous cell carcinoma with uncommon EGFR (Ex18) compound mutations and phosphatidylinositol 3-kinase mutation receiving afatinib at the forefront.

Pulmonary Adenocarcinoma Patient with Complex Mutations on EGFR Benefits from Furmonertinib after Acquiring Gefitinib Resistance: A Case Report

BACKGROUND

Although epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) have been proven a long-lasting treatment effect in pulmonary adenocarcinoma, most patients still progressed within one year due to the acquired resistance. Complex mutations of rare rare sites after acquiring resistance are rarely reported in pulmonary adenocarcinoma.

CASE PRESENTATION

A 62-year-old woman was diagnosed with pulmonary adenocarcinoma with stage IV. Genetic testing at the initial treatment showed EGFR L858R positive. After being treated with gefitinib, persistent 2 years disease progression occurred due to drug resistance. The genetic testing showed that EGFR L858R was eliminated, while a rare rare complex mutation of L861Q/G719X appeared. After 160 mg furmonertinib was treated for 1 month, the primary tumor regressed and the intracranial lesions disappeared. The patient has achieved progression-free survival (PFS) for more than 20 months.

CONCLUSION

Pulmonary adenocarcinoma with rare rare complex mutations in EGFR induced by gefitinib resistance and disease progression might benefit from furmonertinib treatment.

Epidermal growth factor receptor compound and concomitant mutations: advances in precision treatment strategies

ABSTRACT

Epidermal growth factor receptor ( EGFR ) mutations are common oncogenic driver mutations in patients with non-small cell lung cancer (NSCLC). The application of EGFR-tyrosine kinase inhibitors (TKIs) is beneficial for patients with advanced and early-stage NSCLC. With the development of next-generation sequencing technology, numerous patients have been found to have more than one genetic mutation in addition to a single EGFR mutation; however, the efficacy of conventional EGFR-TKIs and the optimal treatments for such patients remain largely unknown. Thus, we review the incidence, prognosis, and current treatment regimens of EGFR compound mutations and EGFR concomitant mutations to provide treatment recommendations and guidance for patients with these mutations.

Survival analysis of patients with advanced non-small cell lung cancer receiving EGFR-TKI treatment of Yunnan in southwestern China: a real-world study

Importance

Patients with EGFR mutations who have advanced-stage non-small cell lung cancer (NSCLC) already receive tyrosine kinase inhibitors (TKIs) as the standard first-line therapy. Notably, Yunnan is a regional high incidence area of lung cancer in the highlands with a high rate of rare EGFR mutations. Overall, lung cancer patients in Xuanwei may present a distinct subgroup globally. Recent studies suggested that the NSCLC cohort in Xuanwei harbored a significantly higher uncommon mutation rate. However, little was known about the clinicopathological features and treatment efficacy of EGFR-TKI in Yunnan NSCLC patients.

Objective

This study aimed to investigate the clinical impact of histologic type on the survival outcomes of patients with stage IIIB and IV NSCLC receiving EGFR-TKI treatment of Yunnan in southwestern China.

Methods

In this retrospective study, we enrolled advanced NSCLC patients (IIIB-IV) with EGFR mutations who were first diagnosed and treated at Yunnan Cancer hospital from January 2016 to December 2019. Sociodemographics, lifestyle, survival, and clinicopathological characteristics of the patients were collected. The Kaplan-Meier method was used to assess the OS and PFS of patients. An analysis of prognostic factors was conducted using Cox regression.

Results

A total of 468 eligible patients were included. The median progression-free survival (PFS) and overall survival(OS) were 11.30(95% CI, 10.12-12.48) months and 30.30(95% CI, 26.24-34.36) months. Based on survival analysis among all the patients,females(HR=0.815;95% CI:0.671-0.989; P=0.017), Xuanwei origin (HR=0.776; 95% CI: 0.609-0.989; P=0.040), sample types(HR=0.780; 95% CI: 0.642-0.947; P=0.012) had a longer PFS. Multivariable analysis showed that only the sample type was an independent factor on median PFS with EGFR-TKI therapy. Patients less than 60 years old (HR=1.433; 95% CI:1.134-1.812, P=0.003)had better OS, but objectives with BMI≥24kg/m2(HR=0.653; 95% CI: 0.500-0.864; P=0.002), females(HR=0.776; 95% CI:0.613-0.982; P=0.035)and patients with tissue sample type (HR=0.760; 95% CI:0.600-.0961; P=0.022) had better OS. Notably, subgroup analysis of our study also found that PFS was significantly better in patients with G719X, L861Q, S768I, G719X+L861Q, and G719X+S768I in Xuanwei than classical mutation ones, including 19-Del and L858R (median 22.7 vs. 12.0 months, HR=0.523, P=0.010), while PFS was inferior in patients with rare mutations of EGFR in non-Xuanwei than the classical mutation ones (median 5.10 vs. 11.10 months, HR=1.760, P=0.015).

Conclusion

NSCLC patients in Yunnan displayed a unique EGFR mutation profile, especially a higher prevalence of EGFR uncommon and compound mutations subtype. This study indicates prognostic factors of NSCLC treated with EGFR-TKI in Yunan and Xuanwei. This study will provide new clinical evidence for EGFR-TKI-targeted therapy in patients with rare EGFR mutations in China and worldwide. More researchs were needed for NSCLC EGFR-TKI therapy and medical insurance policy-making in Yunnan, Xuanwei area and uncommon especially.

SUMOylation of AnxA6 facilitates EGFR-PKCα complex formation to suppress epithelial cancer growth

BACKGROUND

The Annexin A6 (AnxA6) protein is known to inhibit the epidermal growth factor receptor (EGFR)-extracellular signal regulated kinase (ERK)1/2 signaling upon EGF stimulation. While the biochemical mechanism of AnxA6 inactivating phosphorylation of EGFR and ERK1/2 is not completely explored in cancer cells.

METHODS

Cells were transiently co-transfected with pFlag-AnxA6, pHA-UBC9 and pHis-SUMO1 plasmids to enrich the SUMOylated AnxA6 by immunoprecipitation, and the modification level of AnxA6 by SUMO1 was detected by Western blot against SUMO1 antibody. The SUMOylation level of AnxA6 was compared in response to chemical SUMOylation inhibitor treatment. AnxA6 SUMOylation sites were further identified by LC-MS/MS and amino acid site mutation validation. AnxA6 gene was silenced through AnxA6 targeting shRNA-containing pLKO.1 lentiviral transfection in HeLa cells, while AnxA6 gene was over-expressed within the Lenti-Vector carrying AnxA6 or mutant AnxA6^K299R plasmid in A431 cells using lentiviral infections. Moreover, the mutant plasmid pGFP-EGFR^T790M/L858R was constructed to test AnxA6 regulation on EGFR mutation-induced signal transduction. Moreover, cell proliferation, migration, and gefitinib chemotherapy sensitivity were evaluated in HeLa and A431 cells under AnxA6 konckdown or AnxA6 overexpression by CCK8, colony form and wound healing assays. And tumorigenicity in vivo was measured in epithelial cancer cells-xenografted nude mouse model.

RESULTS

AnxA6 was obviously modified by SUMO1 conjugation within Lys (K) residues, and the K299 was one key SUMOylation site of AnxA6 in epithelial cancer cells. Compared to the wild type AnxA6, AnxA6 knockdown and its SUMO site mutant AnxA6^K299R showed less suppression of dephosphorylation of EGFR-ERK1/2 under EGF stimulation. The SUMOylated AnxA6 was prone to bind EGFR in response to EGF inducement, which facilitated EGFR-PKCα complex formation to decrease the EGF-induced phosphorylation of EGFR-ERK1/2 and cyclin D1 expression. Similarly, AnxA6 SUMOylation inhibited dephosphorylation of the mutant EGFR, thereby impeding EGFR mutation-involved signal transduction. Moreover, AnxA6 knockdown or the K299 mutant AnxA6^K299R conferred AnxA6 inability to suppress tumor progression, resulting in drug resistance to gefitinib in epithelial cancer cells. And in epithelial cancer cells-xenografted nude mouse model, both the weight and size of tumors derived from AnxA6 knockdown or AnxA6^K299R mutation-expressing cells were much greater than that of AnxA6-expressing cells.

CONCLUSIONS

Besides EGFR gene mutation, protein SUMOylation modification of EGFR-binding protein AnxA6 also functions pivotal roles in mediating epithelial cancer cell growth and gefitinib drug effect. Video Abstract.

Chemotherapy outcomes in EGFR-TKI resistant patients with common and uncommon EGFR mutation: An exploratory retrospective cohort study

BACKGROUND

Some prospective studies have shown that second-generation tyrosine kinase inhibitors (TKIs) provide better control in patients with non-small cell lung cancer (NSCLC) with uncommon epidermal growth factor receptor (EGFR) mutations. However, studies comparing second-line chemotherapy efficacy between NSCLC patients with common and uncommon EGFR mutations remain rare. This retrospective study compared treatment outcomes in these patients.

METHODS

Patients with EGFR-mutated advanced-stage NSCLC who received first-line EGFR-TKIs in a tertiary referral center were retrospectively reviewed between January 2010 and August 2022. Patients with a negative T790M test at disease progression who received second-line chemotherapy were enrolled. We compared progression-free (PFS) and overall (OS) survival between advanced NSCLC patients with common and uncommon EGFR mutations using Kaplan-Meier and log-rank tests.

RESULTS

In total, 209 (54.8%) patients had a negative T790M mutation test and received second-line chemotherapy, of which 192 (91.8%) had a common EGFR mutation (exon 19 deletion or exon 21 L858R substitution), and 17 (8.2%) had an uncommon EGFR mutation. Patients with common EGFR mutations had significantly longer PFS than those with uncommon EGFR mutations (4.57 vs. 2.57 months, p = 0.031). A Cox proportional hazard regression analysis controlling for potential confounding factors indicated that an uncommon EGFR mutation was an independent prognostic factor for PFS.

CONCLUSION

This study suggests that patients with uncommon EGFR mutations have poorer chemotherapy responses and shorter survival than those with common EGFR mutations. The development of new treatment strategies for these patients remains an unmet need.

Afatinib for the Treatment of NSCLC with Uncommon EGFR Mutations: A Narrative Review

Afatinib, the world's first irreversible ErbB family (containing four different cancer cell epidermal growth factor receptors, including EGFR, HER2, ErbB3, and ErbB4) inhibitor, is a second-generation oral epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI). It can be used as a first-line treatment for locally advanced or metastatic non-small-cell lung cancer (NSCLC) with an EGFR-sensitive mutation or for patients with locally advanced or metastatic squamous lung cancer whose disease progresses during or after platinum-containing chemotherapy. Currently, with the use of third-generation EGFR-TKIs, afatinib is no longer clinically indicated as the first choice for patients with NSCLC who have EGFR-sensitive mutations. However, afatinib showed a considerable inhibitory effect in NSCLC patients with uncommon EGFR mutations (G719X, S768I, and L861Q) according to a combined post hoc analysis of the LUX-Lung2/3/6 trials. With the development of genetic testing technology, the detection rate of uncommon EGFR mutations is increasing. The aim of this paper is to describe in detail the sensitivity of rare EGFR mutations to afatinib and to provide information and a reference for those suffering from advanced NSCLC who have uncommon EGFR mutations.

Overview on Therapeutic Options in Uncommon EGFR Mutant Non-Small Cell Lung Cancer (NSCLC): New Lights for an Unmet Medical Need

The majority of epidermal growth factor receptor (EGFR) mutations (85-90%) are exon 19 deletions and L858R point mutations of exon 21, characterized by high sensitivity to EGFR-tyrosine kinase inhibitors (TKIs). Less is known about uncommon mutations (10-15% of EGFR mutations). The predominant mutation types in this category include exon 18 point mutations, exon 21 L861X, exon 20 insertions, and exon 20 S768I. This group shows a heterogeneous prevalence, partly due to different testing methods and to the presence of compound mutations, which in some cases can lead to shorter overall survival and different sensitivity to different TKIs compared to simple mutations. Additionally, EGFR-TKI sensitivity may also vary depending on the specific mutation and the tertiary structure of the protein. The best strategy remains uncertain, and the data of EGFR-TKIs efficacy are based on few prospective and some retrospective series. Newer investigational agents are still under study, and there are no other approved specific treatments targeting uncommon EGFR mutations. Defining the best treatment option for this patient population remains an unmet medical need. The objective of this review is to evaluate existing data on the outcomes, epidemiology, and clinical characteristics of lung cancer patients with rare EGFR mutations, with a focus on intracranial activity and response to immunotherapy.

A single-arm, multicenter, phase II trial of osimertinib in patients with epidermal growth factor receptor exon 18 G719X, exon 20 S768I, or exon 21 L861Q mutations

BACKGROUND

For patients with stage IV non-small-cell lung cancer with epidermal growth factor receptor (EGFR) exon 19 deletions and exon 21 L858R mutations, osimertinib is the standard of care. Investigating the activity and safety of osimertinib in patients with EGFR exon 18 G719X, exon 20 S768I, or exon 21 L861Q mutations is of clinical interest.

PATIENTS AND METHODS

Patients with stage IV non-small-cell lung cancer with confirmed EGFR exon 18 G719X, exon 20 S768I, or exon 21 L861Q mutations were eligible. Patients were required to have measurable disease, an Eastern Cooperative Oncology Group performance status of 0 or 1, and adequate organ function. Patients were required to be EGFR tyrosine kinase inhibitor-naive. The primary objective was objective response rate, and secondary objectives were progression-free survival, safety, and overall survival. The study used a two-stage design with a plan to enroll 17 patients in the first stage, and the study was terminated after the first stage due to slow accrual.

RESULTS

Between May 2018 and March 2020, 17 patients were enrolled and received study therapy. The median age of patients was 70 years (interquartile range 62-76), the majority were female (n = 11), had a performance status of 1 (n = 10), and five patients had brain metastases at baseline. The objective response rate was 47% [95% confidence interval (CI) 23% to 72%], and the radiographic responses observed were partial response (n = 8), stable disease (n = 8), and progressive disease (n = 1). The median progression-free survival was 10.5 months (95% CI 5.0-15.2 months), and the median OS was 13.8 months (95% CI 7.3-29.2 months). The median duration on treatment was 6.1 months (range 3.6-11.9 months), and the most common adverse events (regardless of attribution) were diarrhea, fatigue, anorexia, weight loss, and dyspnea.

CONCLUSIONS

This trial suggests osimertinib has activity in patients with these uncommon EGFR mutations.

Structure-Guided Strategies of Targeted Therapies for Patients with EGFR-Mutant Non-Small Cell Lung Cancer

Oncogenic mutations within the EGFR kinase domain are well-established driver mutations in non-small cell lung cancer (NSCLC). Small-molecule tyrosine kinase inhibitors (TKIs) specifically targeting these mutations have improved treatment outcomes for patients with this subtype of NSCLC. The selectivity of these targeted agents is based on the location of the mutations within the exons of the EGFR gene, and grouping mutations based on structural similarities has proved a useful tool for conceptualizing the heterogeneity of TKI response. Structure-based analysis of EGFR mutations has influenced TKI development, and improved structural understanding will inform continued therapeutic development and further improve patient outcomes. In this review, we summarize recent progress on targeted therapy strategies for patients with EGFR-mutant NSCLC based on structure and function analysis.

Non-small cell lung cancer with EGFR (L858R and E709X) and CNNB1 mutations responded to afatinib

Lung cancer with complex epidermal growth factor receptor (EGFR) and CTNNB1 comutations is rare, and the efficacy of tyrosine kinase inhibitors (TKIs) is generally poor. Here, we encountered a lung cancer patient with complex EGFR (L858R and E709X) and CTNNB1 comutations who successfully responded to afatinib. A 78-year-old woman visited our hospital with a cough and bloody sputum that had worsened over the past year. She had multiple mass shadows in both lungs and nodular shadows in the bronchi. The patient was diagnosed with lung adenocarcinoma cT4N3M1c stage IVB. A genetic analysis of the primary tumor using the Oncomine Dx target test multi-CDx system revealed positivity for EGFR (L858R and E709X) and CTNNB1 mutations. The expression of programmed death ligand 1 (22C3 clones) in tumor cells was negative by immunostaining. The patient was treated with afatinib as first-line therapy and achieved clinical improvement and a partial response and is continuing treatment 1 year later. Case reports of lung cancer patients with EGFR/CTNNB1 comutations are rare, and TKIs are not considered to be effective. We herein present the first case report of lung cancer with the co-occurrence of uncommon and complex EGFR (L858R and E709X) and CTNNB1 mutations that was successfully treated with afatinib.

Afatinib and Dacomitinib Efficacy, Safety, Progression Patterns, and Resistance Mechanisms in Patients with Non-Small Cell Lung Cancer Carrying Uncommon EGFR Mutations: A Comparative Cohort Study in China (AFANDA Study)

(1) Background: Afatinib has been approved for patients with non-small cell lung cancer (NSCLC) carrying major uncommon epidermal growth factor receptor gene (EGFR) mutations. Dacomitinib, another second-generation tyrosine kinase inhibitor, has also shown promising potential for uncommon EGFR mutations. However, no comparative study has been conducted. (2) Methods: Two cohorts were employed: the AFANDA cohort, an ambispective cohort including 121 patients with uncommon EGFR mutations admitted to two tertiary hospitals in China, and an external validation afatinib cohort (ex-AC), extracted from the Afatinib Uncommon EGFR Mutations Database (N = 1140). The AFANDA cohort was divided into an afatinib cohort (AC) and a dacomitinib cohort (DC) for internal exploration. Objective response rate (ORR), progression-free survival (PFS), and adverse events (AEs) were assessed for comparison. Progression patterns and resistance mechanisms were explored. (3) Results: In total, 286 patients with advanced NSCLC carrying uncommon EGFR mutations treated with afatinib or dacomitinib were enrolled, including 79 in the AFANDA cohort (44 in the DC, 35 in the AC) and 207 in the ex-AC. In internal exploration, the ORR of the DC was significantly higher than that of the AC (60.5 vs. 26.7%, p = 0.008), but there was no significant difference in median PFS between the DC and the AC (12.0 months vs. 10.0 months, p = 0.305). Multivariate analysis confirmed an independent favorable effect of dacomitinib on PFS (hazard ratio (HR), 1.909; p = 0.047). In external validation, multivariate analysis confirmed the independent prognostic role of dacomitinib in PFS (HR, 1.953; p = 0.029). Propensity score matching analysis confirmed the superiority of dacomitinib over afatinib in terms of PFS in both univariate and multivariate analyses. Toxicity profiling analysis suggested more G1 (p = 0.006), but fewer G3 (p = 0.036) AEs in the DC than in the AC. Progression patterns revealed that the incidence of intracranial progression in the AC was significantly higher than that in the DC (50 vs. 21.1%, p = 0.002). Drug resistance analysis indicated no significant difference in the occurrence of T790M between the AC and the DC (11.8 vs. 15.4%, p = 0.772). (4) Conclusions: Compared with afatinib, dacomitinib demonstrated a more favorable activity with manageable toxicity and different progression patterns in patients with NSCLC carrying uncommon EGFR mutations.