Effects of Early Short-Course Corticosteroids on Immune-Related Adverse Events in Non-Small Cell Lung Cancer Patients Receiving Immune Checkpoint Inhibitors.

INTRODUCTION: In real-world practice, most non-small cell lung cancer (NSCLC) patients receiving combined immunochemotherapy are exposed to short-course corticosteroids following immune checkpoint inhibitor (ICI) infusion to prevent chemotherapy-related adverse events. However, whether this early short-course corticosteroid use prevents immune-related adverse events (irAEs) remains unknown. METHODS: Between January 1st, 2015, and December 31st, 2020, NSCLC patients who received at least one cycle of ICI with or without chemotherapy were enrolled. Early short-course corticosteroids were defined as corticosteroids administered following ICI injection and before chemotherapy on the same day and no longer than 3 days afterward. The patients were categorized as either "corticosteroid group" or "non-corticosteroid group" depending on their exposure to early short-course corticosteroid. The frequencies of irAEs requiring systemic corticosteroid use and irAEs leading to ICI discontinuation were compared between the two groups, and exploratory survival analyses were performed. RESULTS: Among 252 eligible patients, 137 patients were categorized as "corticosteroid group" and 115 patients as "non-corticosteroid group." The corticosteroid group enriched patients in the first-line setting (n = 75, 54.7%), compared to the non-corticosteroid group (n = 28, 24.3%). Thirty patients (21.9%) in the corticosteroid group and 35 patients (30.4%) in the non-corticosteroid group developed irAEs requiring systemic corticosteroid use (odds ratio [OR], 0.64; 95% confidence interval [CI], 0.35-1.18; p = 0.15). Eight patients (5.8%) in the corticosteroid group, as compared with 18 patients (15.7%) in the non-corticosteroid group, permanently discontinued ICI due to irAEs (OR, 0.34; 95% CI, 0.12-0.85; p = 0.013). CONCLUSION: Early short-course corticosteroids following each ICI injection may reduce the rate of irAEs that lead to ICIs discontinuation, warranting further investigation of its prophylactic use to mitigate clinically significant irAEs.

Short-course pembrolizumab and continuous afatinib therapy for recurrent or metastatic head and neck squamous cell carcinoma: a real-world data analysis.

OBJECTIVES: The optimal duration of anti-PD-1 for cancer therapy has not been tested, especially when using combination therapy. Epidermal growth factor receptor (EGFR) pathway blocker was the top compound that enhanced T-cell killing of tumor cells in a high-throughput immune-oncology screen, possibly by stimulate the antigen presentation machinery and other mechanisms. We explored the effect of combination of EGFR inhibition with a short course of anti-PD-1 therapy in patients with recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC). METHOD: We analyzed the effect of a short course of anti-PD-1 with continuous afatinib on the survival of a real-world cohort of R/M HNSCC patients. Patient characteristics, treatments, efficacies, and toxicities were reviewed and recorded for analysis. RESULTS: From November 2016 to May 2018, 51 consecutive patients received pembrolizumab and afatinib. The cutoff date was June 30, 2022. The most common toxicities (all grades) were diarrhea (62.7%), skin rash (43.1%), mucositis (31.4%), and paronychia (23.5%). The objective response rate was 54.9% (95% confidence interval [CI] 40.3-68.9%). Median progression-free survival was 5.9 months (95% CI: 4.4-7.6 months), and the median overall survival was 10.5 months (95% CI: 6.8-16.5 months). The 12-month, 24-month, 36-month, and 48-month survival rate was 47.0%, 22.5%, 17.7%, and 12.6% respectively. CONCLUSIONS: This retrospective study showed that short course pembrolizumab with afatinib therapy has acceptable efficacy in R/M HNSCC patients. The durable response and long-term survival rates were similar to prospective clinical trials. Short course anti-PD-1 therapy, especially in combination with EGFR blocker, is worth for further prospective study.

Association of Programmed Death-Ligand 1 Expression with Fusion Variants and Clinical Outcomes in Patients with Anaplastic Lymphoma Kinase-Positive Lung Adenocarcinoma Receiving Crizotinib.

BACKGROUND: Programmed death-ligand 1 (PD-L1) expression is associated with clinical outcomes of epidermal growth factor receptor (EGFR) mutant lung adenocarcinoma (ADC) treated with tyrosine kinase inhibitors (TKIs). However, whether PD-L1 expression plays a role in anaplastic lymphoma kinase (ALK)-positive lung ADC is unknown. We aimed to evaluate the impact of PD-L1 in patients with ALK-positive lung ADC receiving crizotinib. MATERIALS AND METHODS: PD-L1 expression was identified by immunohistochemistry (IHC). Reverse transcriptase-polymerase chain reaction was used for ALK variant detection, and immunofluorescence-based multiplex staining was applied for exploring immune cells in tumor microenvironments. RESULTS: A total of 78 patients with ALK-positive advanced ADC were enrolled in our study, of whom 52 received crizotinib. Compared with EGFR/ALK wild-type tumors, PD-L1 expression was lower in ALK-positive ADC. ALK fusion variants were identified in 32 patients, and those with variant 3 and 5 (short variants) had higher PD-L1 expression than those with other variants. The crizotinib objective response rate (ORR) and progression-free survival (PFS) was better in tumors with negative PD-L1 expression (ORR/PFS in PD-L1 0% vs. 1%-49% vs. 50%-100%: 60.7%/11.8 months vs. 38.5%/6.5 months vs. 36.4%/4.0 months, p = .007/.022). The multivariate Cox proportional hazards model revealed that PD-L1 0% (vs. ≥1%) was an independent factor for longer PFS (adjusted hazard ratio 0.322, 95% confidence interval 0.160-0.650, p = .002). Multiplex IHC in three cases showed a varied extent of immune cell infiltrations in tumors with different PD-L1 expression. CONCLUSION: Positive PD-L1 expression was associated with unfavorable clinical outcomes in patients with ALK-positive lung ADC receiving crizotinib. IMPLICATIONS FOR PRACTICE: Not all lung adenocarcinoma with sensitizing driver mutations experienced durable responses to small-molecule tyrosine kinase inhibitors (TKIs). Similar to the negative impact of programmed death-ligand 1 (PD-L1) in epidermal growth factor receptor mutant tumors treated with TKIs, this study demonstrated that positive PD-L1 expression was also associated with worse response rate and shorter progression-free survival of anaplastic lymphoma kinase (ALK)-positive adenocarcinoma treated with crizotinib. Among different ALK fusion partners, tumors with short variants (V3 and V5) had higher PD-L1 compared with long variants (V1, V2, and V6). Testing PD-L1 before initiating crizotinib for ALK-positive lung cancer could be a simple method to provide important prognostic information.

Outcomes of research biopsies in clinical trials of EGFR mutation-positive non-small cell lung cancer patients pretreated with EGFR-tyrosine kinase inhibitors.

BACKGROUND/PURPOSE: Research biopsies (RBs) are crucial for developing novel molecular targeted agents. However, the safety and diagnostic yields of RBs have not been investigated in EGFR mutation-positive non-small cell lung cancer (NSCLC) patients pretreated with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs). METHODS: We searched the medical records of NSCLC patients who participated in lung cancer clinical trials and underwent mandatory RBs between 2012 and 2014 at our institution. Only patients with EGFR mutation-positive NSCLC pretreated with at least 1 EGFR-TKI were enrolled. RESULTS: Of 140 enrolled patients, 73 (52.1%) and 59 (42.1%) had exon 19 deletions and exon 21 L858R mutation, respectively. Before RBs, 108 (77.1%), 83 (59.3%), and 36 (25.7%) patients had been treated with gefitinib, erlotinib, and afatinib, respectively. Computed tomography-guided percutaneous core needle biopsy was the most frequently used modality among 181 RBs performed (50.8%), followed by ultrasonography-guided (32.0%) and endoscopic RBs (16.0%). The most common RB sites were the lung (69.6%), pleura (8.8%), and liver (6.1%). Pathologic examinations revealed malignant cells in most RB specimens (72.9%). Complications due to RBs included pneumothorax (11.6%), bleeding (6.1%), and infection (1.1%). Only 1 patient required chest tube placement for pneumothorax, and 2 patients underwent endotracheal intubation because of bleeding. CONCLUSION: RBs in this patient population were generally safe. Pneumothorax was the most frequent complication; bleeding, while infrequent, increased the risk of severe events. The diagnostic yields and complications of any particular modality should therefore be discussed with prospective clinical trial participants.

Novel EGFR Inhibitors in Non-small Cell Lung Cancer: Current Status of Afatinib.

Afatinib, a second-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, has been approved worldwide as a first-line treatment for advanced non-small cell lung cancer (NSCLC) that harbors activating EGFR mutations. Here, we have reviewed the recent clinical developments in the treatment of lung cancer using afatinib. Emerging data have revealed the overall survival benefit of first-line afatinib therapy in patients with advanced EGFR del19-positive NSCLC. Phase III studies of afatinib have shown the effectiveness of afatinib as a second-line treatment for advanced lung squamous cell carcinoma, as well as the benefit of continuing afatinib therapy in combination with cytotoxic chemotherapy for advanced NSCLC after the occurrence of disease progression in patients who are receiving afatinib monotherapy. Therapeutic benefits of afatinib have also been reported in studies of patients with central nervous system metastasis and patients with HER2 mutation. The utility of afatinib-based combination therapies is being investigated in ongoing research.

Update on recent preclinical and clinical studies of T790M mutant-specific irreversible epidermal growth factor receptor tyrosine kinase inhibitors.

The first- and second-generation epidermal growth factor receptor tyrosine kinase inhibitors (1/2G EGFR-TKIs) gefitinib, erlotinib, and afatinib have all been approved as standard first-line treatments for advanced EGFR mutation-positive non-small cell lung cancer. The third-generation (3G) EGFR-TKIs have been developed to overcome the EGFR T790M mutation, which is the most common mechanism of acquired resistance to 1/2G EGFR-TKI treatment. This resistance mutation develops in half of the patients who respond to 1/2G EGFR-TKI therapy. The structures of the novel 3G EGFR-TKIs are different from those of 1/2G EGFR-TKIs. Particularly, 3G EGFR-TKIs have lower affinity to wild-type EGFR, and are therefore associated with lower rates of skin and gastrointestinal toxicities. However, many of the adverse events (AEs) that are observed in patients receiving 3G EGFR-TKIs have not been observed in patients receiving 1/2G EGFR-TKIs. Although preclinical studies have revealed many possible mechanisms for these AEs, the causes of some AEs remain unknown. Many mechanisms of resistance to 3G EGFR-TKI therapy have also been reported. Here, we have reviewed the recent clinical and preclinical developments related to novel 3G EGFR-TKIs, including osimertinib, rociletinib, olmutinib, EGF816, and ASP8273.

Second and third-generation epidermal growth factor receptor tyrosine kinase inhibitors in advanced nonsmall cell lung cancer.

PURPOSE OF REVIEW: The first-generation epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), gefitinib and erlotinib, are effective as first-line treatment of advanced nonsmall cell lung cancer (NSCLC) harboring activating EGFR mutations (deletions in exon 19 and exon 21 L858R mutation). EGFR T790 M resistance mutation (EGFR T790 M) ultimately emerged in most of these patients. The second and third-generation EGFR-TKIs were designed to have more potent inhibition of EGFR and to overcome EGFR T790 M. This review describes the recent developments of these novel EGFR-TKIs. RECENT FINDINGS: The second-generation EGFR-TKIs, afatinib and dacomitinib, irreversibly bind to the tyrosine kinase of EGFR and other ErbB-family members. Afatinib has been approved as first-line treatment of advanced NSCLC harboring activating EGFR mutations. Dacomitinib is under development. Third-generation EGFR-TKIs, AZD9291, CO-1686, and HM61713, inhibit both EGFR activating and resistance mutations, while sparing wild-type EGFR. In early-phase studies, these drugs demonstrated promising response rates against tumors with acquired EGFR T790 M. SUMMARY: Second-generation EGFR-TKI, afatinib, is available as first-line treatment of advanced NSCLC harboring activating EGFR mutations. Third-generation EGFR-TKIs are under development for tumors harboring acquired EGFR T790 M.

Registry of Genetic Alterations of Taiwan Non-Small Cell Lung Cancer by Comprehensive Next-Generation Sequencing: A Real-World Cohort Study-Taiwan Cooperative Oncology Group T1521.

PURPOSE: Tissue-based next-generation sequencing (NGS) analysis is highly recommended for patients with advanced/metastatic non-small cell lung cancer (NSCLC). We investigated a specific patient population with NSCLC that required tissue-based NGS analysis. MATERIALS AND METHODS: We enrolled 500 patients with advanced/metastatic (1) epidermal growth factor receptor (EGFR) mutations or anaplastic large-cell lymphoma kinase (ALK) rearrangement-positive NSCLC who had failed at minimum one line of tyrosine kinase inhibitor (TKI) therapy, (2) EGFR-/ALK-negative nonsquamous, and (3) non- or light-smoker patients with squamous NSCLC who were treatment-naïve or had failed at maximum two lines of systemic treatment. These patients were divided into five cohorts. Comprehensive tissue-based NGS testing (ACTOnco+) was conducted. RESULTS: Cohort 1: EGFR TKI-pretreated EGFR-mutated population (50.0%, n = 250), cohort 2: ALK inhibitor-pretreated ALK-positive population (1.6%, n = 8), cohort 3: treatment-naïve EGFR-/ALK-negative population (28.2%, n = 141), cohort 4: pretreated EGFR-/ALK-negative population (16.8%, n = 84), and cohort 5: squamous cell carcinoma (3.4%, n = 17). In cohort 1, 11.2% (28/250) of the patients had MET amplification, 32.4% (81/250) had been treated with osimertinib, and EGFR C797S was detected in 6.2% (5/81) of these patients. In cohort 2, resistance ALK mutation was detected in 37.5% (3/8) of the patients. In cohorts 3 and 4, targetable genetic alterations, including EGFR mutation (13.3%), ERBB2 mutation (9.3%), MET exon 14 skipping (5.3%), KRAS G12C mutation (4.4%), ROS1 fusion (2.7%), RET fusion (1.8%), and BRAF V600E mutation (1.3%), were detected. In cohort 5, MET exon 14 skipping was detected in 29.4% (5/17) of the patients. CONCLUSION: This multicenter registration study investigated tissue-based NGS for a specific patient population with NSCLC in Taiwan.

The branched N-glycan of PD-L1 predicts immunotherapy responses in patients with recurrent/metastatic HNSCC.

Immunotherapy has revolutionized cancer treatment, but the lack of a reliable predictive biomarker for treatment response remains a challenge. Alpha-1,6-Mannosylglycoprotein 6-ß-N-Acetylglucosaminyltransferase 5 (MGAT5) is a key regulator of complex N-glycan synthesis, and its dysregulation is associated with cancer progression. The lectin Phaseolus vulgaris leukoagglutinin (PHA-L) specifically binds to mature MGAT5 products. Previous studies have indicated elevated PHA-L staining in head and neck squamous cell carcinoma (HNSCC), which implies increased activity of MGAT5. However, the specific role of MGAT5 in HNSCC remains unclear. In this study, we found significantly higher PHA-L staining and MGAT5 expression in HNSCC tumors compared to adjacent non-tumor tissues. Using a mass spectrometry (MS)-based glycoproteomic approach, we identified 163 potential protein substrates of MGAT5. Functional analysis revealed that protein substrates of MGAT5 regulated pathways related to T cell proliferation and activation. We further discovered that PD-L1 was among the protein substrates of MGAT5, and the expression of MGAT5 protected tumor cells from cytotoxic T lymphocyte (CTL) killing. Treatment of nivolumab alleviated the protective effects of MGAT5 on CTL activity. Consistently, patients with MGAT5-positive tumors showed improved responses to immunotherapy compared to those with MGAT5-negative tumors. Using purified PD-L1 from HNSCC cells and a glycoproteomic approach, we further deciphered that the N35 and N200 sites carry the majority of complex N-glycans on PD-L1. Our findings highlight the critical role of MGAT5-mediated branched N-glycans on PD-L1 in modulating the interaction with the immune checkpoint receptor PD-1. Consequently, we propose that MGAT5 could serve as a biomarker to predict patients' responses to anti-PD-1 therapy. Furthermore, targeting the branched N-glycans at N35 and N200 of PD-L1 may lead to the development of novel diagnostic and therapeutic approaches.

Clinical efficacy and biomarker analysis of dual PD-1/CTLA-4 blockade in recurrent/metastatic EBV-associated nasopharyngeal carcinoma.

Single-agent checkpoint inhibitor (CPI) activity in Epstein-Barr Virus (EBV) related nasopharyngeal carcinoma (NPC) is limited. Dual CPI shows increased activity in solid cancers. In this single-arm phase II trial (NCT03097939), 40 patients with recurrent/metastatic EBV-positive NPC who failed prior chemotherapy receive nivolumab 3 mg/kg every 2 weeks and ipilimumab 1 mg/kg every 6 weeks. Primary outcome of best overall response rate (BOR) and secondary outcomes (progression-free survival [PFS], clinical benefit rate, adverse events, duration of response, time to progression, overall survival [OS]) are reported. The BOR is 38% with median PFS and OS of 5.3 and 19.5 months, respectively. This regimen is well-tolerated and treatment-related adverse events requiring discontinuation are low. Biomarker analysis shows no correlation of outcomes to PD-L1 expression or tumor mutation burden. While the BOR does not meet pre-planned estimates, patients with low plasma EBV-DNA titre (<7800 IU/ml) trend to better response and PFS. Deep immunophenotyping of pre- and on-treatment tumor biopsies demonstrate early activation of the adaptive immune response, with T-cell cytotoxicity seen in responders prior to any clinically evident response. Immune-subpopulation profiling also identifies specific PD-1 and CTLA-4 expressing CD8 subpopulations that predict for response to combined immune checkpoint blockade in NPC.

A Phase II Study of Osimertinib in Patients with Advanced-Stage Non-Small Cell Lung Cancer following Prior Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor (EGFR TKI) Therapy with EGFR and T790M Mutations Detected in Plasma Circulating Tumour DNA (PLASMA Study).

Epidermal growth factor receptor (EGFR) T790M mutations drive resistance in 50% of patients with advanced non-small cell lung cancer (NSCLC) who progress on first/second generation (1G/2G) EGFR tyrosine kinase inhibitors (TKIs) and are sensitive to Osimertinib. Tissue sampling is the gold-standard modality of T790M testing, but it is invasive. We evaluated the efficacy of Osimertinib in patients with EGFR mutant NSCLC and T790M in circulating tumour DNA (ctDNA). PLASMA is a prospective, open-label, multicentre single-arm Phase II study. Patients with advanced NSCLC harbouring sensitizing EGFR and T790M mutations in plasma at progression from ≥one 1G/2G TKI were treated with 80 mg of Osimertinib daily until progression. The primary endpoint was the objective response rate (ORR); the secondary endpoints included progression-free survival (PFS), overall survival (OS), disease control rate (DCR) and toxicities. Plasma next-generation sequencing was performed to determine Osimertinib resistance mechanisms and assess serial ctDNA. A total of 110 patients from eight centres in five countries were enrolled from 2017 to 2019. The median follow-up duration was 2.64 (IQR 2.44-3.12) years. The ORR was 50.9% (95% CI 41.2-60.6) and the DCR was 84.5% (95% CI 76.4-90.7). Median PFS was 7.4 (95% CI 6.0-9.3) months; median OS was 1.63 (95% CI 1.35-2.16) years. Of all of the patients, 76% had treatment-related adverse events (TRAEs), most commonly paronychia (22.7%); 11% experienced ≥ Grade 3 TRAEs. The ctDNA baseline load and dynamics were prognostic. Osimertinib is active in NSCLC harbouring sensitizing EGFR and T790M mutations in ctDNA testing post 1G/2G TKIs.

Afatinib and Pembrolizumab for Recurrent or Metastatic Head and Neck Squamous Cell Carcinoma (ALPHA Study): A Phase II Study with Biomarker Analysis.

PURPOSE: EGFR pathway inhibition may promote anti-programmed cell death protein 1 (PD-1) responses in preclinical models, but how EGFR inhibition affects tumor antigen presentation during anti-PD-1 monotherapy in humans remain unknown. We hypothesized that afatinib, an irreversible EGFR tyrosine kinase inhibitor, would improve outcomes in patients treated with pembrolizumab for recurrent or metastatic head and neck squamous cell carcinoma (HNSCC) by promoting antigen presentation and immune activation in the tumor microenvironment. PATIENTS AND METHODS: The ALPHA study (NCT03695510) was a single-arm, Phase II study with Simon's 2-stage design. Afatinib and pembrolizumab were administered to patients with platinum-refractory, recurrent, or metastatic HNSCC. The primary endpoint was the objective response rate (ORR). The study applied gene expression analysis using a NanoString PanCancer Immune Profiling Panel and next-generation sequencing using FoundationOne CDx. RESULTS: From January 2019 to March 2020, the study enrolled 29 eligible patients. Common treatment-related adverse events were skin rash (75.9%), diarrhea (58.6%), and paronychia (44.8%). Twelve patients (41.4%) had an objective partial response to treatment. The median progression-free survival was 4.1 months, and the median overall survival was 8.9 months. In a paired tissue analysis, afatinib-pembrolizumab were found to upregulate genes involved in antigen presentation, immune activation, and natural killer cell-mediated cytotoxicity. Unaltered methylthioadenosine phosphorylase and EGFR amplification may predict the clinical response to the therapy. CONCLUSIONS: Afatinib may augment pembrolizumab therapy and improve the ORR in patients with HNSCC. Bioinformatics analysis suggested the enhancement of antigen presentation machinery in the tumor microenvironment.

CD73 Is Regulated by the EGFR-ERK Signaling Pathway in Non-small Cell Lung Cancer.

BACKGROUND/AIM: Successful therapy of EGFR-mutant NSCLC remains a challenging task despite initial benefits with the usage of EGFR tyrosine kinase inhibitors. Cancer immunotherapy has shown promising results in certain tumors, but response rate in EGFR-mutant NCLC is low, because these tumors are thought to have weak immunogenicity. MATERIALS AND METHODS: We used data from in vivo NSCLC databases as well as from in vitro cell culture experiments to investigate the regulation of CD73 by EGFR. RESULTS: EGFR expression was correlated with CD73 expression in patients' datasets, with EGFR-mutant tumors showing higher expression than their EGFR wildtype counterparts. Treatment of EGFR-mutant NSCLC cell lines with EGFR TKI reduced expression of CD73 at both mRNA and protein level. Among EGFR downstream signaling pathways, the Ras-Raf-ERK pathway was involved in the regulation of CD73 expression directly via ERK1/2 without the engagement of RSKs or MSKs. CONCLUSION: The results of this study may provide novel therapeutic strategies for the treatment of oncogene-driven NSCLC.

Serial Plasma Cell-Free Circulating Tumor DNA Tests Identify Genomic Alterations for Early Prediction of Osimertinib Treatment Outcome in EGFR T790M-Positive NSCLC.

INTRODUCTION: Recent advances in the detection of genomic DNA from plasma samples allow us to follow tumor DNA shedding in plasma during systemic treatment. Osimertinib is the standard of care for patients with NSCLC with acquired EGFR T790M mutations. We assessed changes in serial plasma cell-free circulating tumor DNA (ctDNA) genomic alterations to predict osimertinib efficacy. METHODS: We prospectively collected plasma from patients having EGFR-mutated advanced NSCLC previously treated with EGFR tyrosine kinase inhibitor therapy and with acquired EGFR T790M mutation detected by standard methods. Plasma samples were collected before starting osimertinib treatment, 4 weeks after osimertinib treatment, and on progression. ctDNA was analyzed using the Guardant360 assay. RESULTS: A total of 15 eligible patients received osimertinib. Before starting treatment, EGFR-activating mutations were detected in the ctDNA of all patients, and EGFR T790M was detected in 93% of the cases. Osimertinib treatment was associated with an objective response rate of 53% and a median progression-free survival of 7.3 months. A total of 12 of the 15 patients had undetectable plasma T790M and decreased activating mutation allelic frequency (AF) at week 4. None of the 12 patients had disease progression within 16 weeks. For the remaining three patients, with detectable plasma T790M (n = 2) or increased activating mutation AF (n = 1) at week 4, two had progressive disease within 16 weeks (p = 0.03). CONCLUSIONS: In patients with EGFR-mutated advanced NSCLC, persistent EGFR T790M or increasing activating mutation AF as detected in ctDNA 4 weeks after the start of osimertinib treatment may predict disease progression within 16 weeks.

Exon 16-Skipping HER2 as a Novel Mechanism of Osimertinib Resistance in EGFR L858R/T790M-Positive Non-Small Cell Lung Cancer.

INTRODUCTION: Osimertinib is the current recommended treatment for EGFR T790M-positive NSCLC after EGFR tyrosine kinase inhibitor therapy. However, resistance to osimertinib therapy is inevitably acquired after a period of effective treatment. We had a patient with EGFR L858R/T790M-positive NSCLC who initially responded to osimertinib therapy but eventually experienced development of resistance. Plasma cell-free DNA analysis revealed the occurrence of exon 16-skipping HER2, which may have resulted in the erb-b2 receptor tyrosine kinase 2 gene (HER2) splice variant HER2D16. HER2D16 has never been reported in lung cancer, and HER2D16-driven signaling is known to be regulated by Src kinase in breast cancer. We investigated the role of HER2D16 as an osimertinib-resistant mechanism. METHODS: We constructed and established H1975 cells stably expressing HER2D16. The dimeric formation of HER2D16 was tested by using nonreducing polyacrylamide gel electrophoresis. The effects of the study drugs on signaling transduction were examined by using Western blot. Synergistic effect was assessed by using the Chou-Talalay method. RESULTS: We found that HER2D16 can form a homodimer in NSCLC cells. HER2D16-expressing H1975 cells were resistant to osimertinib treatment. We also found that mutant EGFR and HER2D16 cooperated to activate downstream signaling for osimertinib resistance. In addition, cotreatment with osimertinib and an Src kinase inhibitor failed to reverse resistance, indicating that HER2D16-driven signaling in NSCLC did not occur through a canonical pathway. Finally, we revealed that the combination of osimertinib with the pan-HER small-molecule inhibitor afatinib could synergistically repress cell growth and signaling in H1975-HER2D16 cells. CONCLUSION: HER2D16 can contribute to osimertinib resistance through an Src-independent pathway. HER2D16 should be included in the molecular diagnosis panel for lung cancer.

Association between programmed death-ligand 1 expression, immune microenvironments, and clinical outcomes in epidermal growth factor receptor mutant lung adenocarcinoma patients treated with tyrosine kinase inhibitors.

INTRODUCTION: Besides being a predictive biomarker of response to immunotherapy in lung cancer in general, programmed death-ligand 1 (PD-L1) is not so well correlated with treatment outcomes of lung adenocarcinoma (ADC) harbouring epidermal growth factor receptor (EGFR) mutations, as reported studies are inconclusive and seldom addressed the issues of response to treatment and resistance. The primary objective is to evaluate the association of PD-L1 and EGFR tyrosine kinase inhibitor (TKI) efficacy, resistance, and relevant clinical outcomes. The secondary objective is to further explore the tumour microenvironments of EGFR mutant tumours with different PD-L1 expression. METHODS AND MATERIALS: Using immunohistochemical (IHC) staining, we retrospectively tested PD-L1 expression (Dako 22C3) in the pre-treatment tumours from advanced EGFR mutant lung ADC patients, of whom all were treated with TKIs. Multiplex IHC assay was applied for exploring immune cells in tumour microenvironments. RESULTS: A total of 153 Taiwanese patients were enrolled in our study, of whom a majority of cases were female (58.9%) and non-smokers (75.8%). The objective response rate (ORR) to EGFR TKI and progression-free survival (PFS) were better in patients with PD-L1 expression <50% (ORR/PFS in PD-L1 0% versus 1-49% versus ≥50%: 65.6%/12.5 months versus 56.4%/12.8 months versus 38.9%/5.9 months, P < 0.05). The multivariate analysis showed that PD-L1 <50% was an independent prognostic factor for longer PFS (hazard ratio (HR) 0.433, 95% confidence interval (CI) 0.250-0.751, P = 0.003). Furthermore, tumours with higher PD-L1 expression were less likely to develop a secondary T790M mutation (T790M+ in PD-L1 0% versus 1-49% versus ≥50%: 53.7% versus 35.7% versus 10%, P = 0.024). Multiplex IHC tests were applied in 15 cases and revealed a potential correlation between PD-L1, immune cells, and EGFR TKI responses. CONCLUSIONS: Lower pre-treatment PD-L1 is associated with better ORR, PFS, and higher frequency of T790M resistance in EGFR TKI-treated lung ADC patients.

Second-line treatment of EGFR T790M-negative non-small cell lung cancer patients.

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are the currently recommended treatment for advanced EGFR mutation-positive non-small cell lung cancer (NSCLC). Acquired resistance inevitably develops, with the EGFR T790M mutation comprising approximately 55% of the mechanisms of resistance following first- or second-generation EGFR-TKI therapy (e.g. gefitinib, erlotinib, afatinib, and dacomitinib). Patients without T790M are a heterogeneous group for whom platinum-based chemotherapy is currently recommended as a second-line treatment. In addition to secondary mutations in EGFR (e.g. T790M), the currently known resistance mechanisms can be classified into the following three categories: bypass pathways, downstream signaling pathways, and histologic transformations. Given the evolving knowledge and convenience of diagnosing acquired resistance mechanisms by next-generation sequencing and liquid biopsy, exploratory studies targeting these resistance mechanisms and incorporating immunotherapy into the treatment paradigm have become the mainstream of future development. This review focuses on acquired resistance mechanisms other than T790M that develop after first- or second-generation EGFR-TKI therapy. Exploratory second-line treatments targeting resistance mechanisms as well as combination immunotherapy and chemotherapy in ongoing clinical trials are reviewed here. We also highlight the recent development of next-generation sequencing and liquid biopsy in this field.

Treating brain metastases in non-small cell lung cancer patients: what have we learnt from pharmaceutical recent clinical trials?

INTRODUCTION: Brain metastases (BMs) develop in up to 40% of patients with non-small cell lung cancer (NSCLC). In many recent practice-changing clinical trials, patients with BM were included; however, only few trials reported intracranial efficacies in either post hoc or pre-planned analysis. Clinically meaningful intracranial efficacy data of novel agents have not been completely disclosed. AREAS COVERED: The authors performed a systemic review of recent pharmaceutical clinical trials, mainly pivotal or practice-changing trials. Some of the prospective clinical trials focused on patients with NSCLC and BM. The authors collected and compared intracranial efficacy reports of chemotherapy, epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), ALK inhibitors, and immune checkpoint inhibitors. EXPERT OPINION: Many clinical trials, especially those on 'brain-active' EGFR-TKIs and ALK inhibitors, have robust reports of intracranial efficacies either as post hoc or pre-planned analysis. Physicians should interpret this data with caution and apply the results to patients accordingly. For the design of future clinical trials, enrolling patients with only BM, incorporating novel risk classifications, pre-planning intracranial efficacy endpoints, reporting prior local brain therapies, and applying novel response evaluation criteria are emerging trends in this area.

Tumor PD-L1 Expression and Clinical Outcomes in Advanced-stage Non-Small Cell Lung Cancer Patients Treated with Nivolumab or Pembrolizumab: Real-World Data in Taiwan.

Background: Immunotherapy that targets programmed death protein-1 (PD-1) provides improved treatment efficacy and survival in patients with metastatic non-small cell lung cancer (NSCLC), especially those with high tumor expression of PD-L1. However, data on this treatment are mostly from clinical trials enrolling highly selected patients. The real-world experience of anti-PD-1 treatment and the usefulness of tumor PD-L1 expression in prediction of treatment response are largely unknown. Methods: We retrospectively reviewed patients with stage IIIB/ IV NSCLC who received monotherapy with nivolumab or pembrolizumab, and evaluated response using RECIST 1.1 criteria. Factors associated with treatment response, progression free survival (PFS), and overall survival (OS) were determined. Results: Seventy-four NSCLC patients out of 116 examined patients were included, most of whom had adenocarcinoma (48/74, 64.9%) and received immunotherapy as a third-line or subsequent treatment (51/74, 68.9%). The median PFS and OS were 1.8 and 7.9 months, respectively. The objective response rate was 32%, but only 47 of 74 patients were evaluable. Through multivariate analysis, epidermal growth factor receptor (EGFR) mutation was independently associated with a poor treatment response. Good performance status (ECOG≤1) and smoking were independently associated with better PFS and OS. Data on tumor PD-L1 expression were available in 43 patients (58%); higher PD-L1 expression correlated with better treatment response and longer PFS. Severe treatment-related adverse events were uncommon. Conclusion: The efficacy and safety of anti-PD-1 medications for advanced NSCLC were comparable in real-world and clinical settings, except in those with poor ECOG scores. Prediction of treatment response from tumor PD-L1 expression seemed practical.

Optimal management of EGFR-mutant non-small cell lung cancer with disease progression on first-line tyrosine kinase inhibitor therapy.

The first-generation epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), gefitinib and erlotinib, and the second-generation EGFR-TKI, afatinib, have all been approved as standard first-line treatments for advanced EGFR-mutant non-small cell lung cancer (NSCLC) based on superior progression-free survival results compared to platinum doublet chemotherapy regimens. Acquired resistance to an EGFR-TKI inevitably develops after a period of effective drug treatment. After tumor progression, many combination therapy regimens that include an EGFR-TKI, or EGFR-TKI monotherapy, have been tested in prospective trials with the aim of extending survival. Third-generation EGFR-TKIs such as osimertinib have been developed with the aim of overcoming the effects of EGFR T790M resistance mutation, which occurs in half of the patients with disease progression on EGFR-TKI therapy. Osimertinib has become the standard treatment in patients for whom tumor re-biopsy reveals an acquired EGFR T790M mutation following EGFR-TKI therapy. Other third-generation EGFR-TKIs, such as olmutinib, EGF816, and ASP8273, are still in the trial phase.