HER2 exon 20 insertions in non-small-cell lung cancer are sensitive to the irreversible pan-HER receptor tyrosine kinase inhibitor pyrotinib

Novel therapeutic strategies for rare mutations in non-small cell lung cancer

Lung cancer is still the leading cause of cancer-related mortality. Over the past two decades, the management of non-small cell lung cancer (NSCLC) has undergone a significant revolution. Since the first identification of activating mutations in the epidermal growth factor receptor (EGFR) gene in 2004, several genetic aberrations, such as anaplastic lymphoma kinase rearrangements (ALK), neurotrophic tropomyosin receptor kinase (NTRK) and hepatocyte growth factor receptor (MET), have been found. With the development of gene sequencing technology, the development of targeted drugs for rare mutations, such as multikinase inhibitors, has provided new strategies for treating lung cancer patients with rare mutations. Patients who harbor this type of oncologic driver might acquire a greater survival benefit from the use of targeted therapy than from the use of chemotherapy and immunotherapy. To date, more new agents and regimens can achieve satisfactory results in patients with NSCLC. In this review, we focus on recent advances and highlight the new approval of molecular targeted therapy for NSCLC patients with rare oncologic drivers.

Discovery of Novel 5,6-Dihydro-4H-pyrido[2,3,4-de]quinazoline Irreversible Inhibitors Targeting Both Wild-Type and A775_G776insYVMA Mutated HER2 Kinases

HER2 mutations were seen in 4% of non-small-cell lung cancer (NSCLC) patients. Most of these mutations (90%) occur as an insertion mutation within the exon 20 frame, leading to the downstream activation of the PI3K-AKT and RAS/MAPK pathways. However, no targeted therapies have yet been approved worldwide. Here a novel series of highly potent HER2 inhibitors with a pyrido[2,3,4-de]quinazoline core were designed and developed. The derivatives with the pyrido[2,3,4-de]quinazoline core displayed superior efficacy of antiproliferation in BaF3 cells harboring HER2insYVMA mutation compared with afatinib and neratinib. Rat studies showed that 8a and 9a with the newly developed core have good pharmacokinetic properties with an oral bioavailability of 41.7 and 42.0%, respectively. Oral administration of 4a and 10e (30 mg/kg, QD) displayed significant antitumor efficacy in an in vivo xenograft model. We proposed promising strategies for the development of HER2insYVMA mutant inhibitors in this study.

Ex vivo drug testing of patient-derived lung organoids to predict treatment responses for personalized medicine

Lung cancer is the leading cause of global cancer-related mortality resulting in ∼ 1.8 million deaths annually. Systemic, molecular targeted, and immune therapies have provided significant improvements of survival outcomes for patients. However, drug resistance usually arises and there is an urgent need for novel therapy screening and personalized medicine. 3D patient-derived organoid (PDO) models have emerged as a more effective and efficient alternative for ex vivo drug screening than 2D cell culture and patient-derived xenograft (PDX) models. In this review, we performed an extensive search of lung cancer PDO-based ex vivo drug screening studies. Lung cancer PDOs were successfully established from fresh or bio-banked sections and/or biopsies, pleural effusions and PDX mouse models. PDOs were subject to ex vivo drug screening with chemotherapy, targeted therapy and/or immunotherapy. PDOs consistently recapitulated the genomic alterations and drug sensitivity of primary tumors. Although sample sizes of the previous studies were limited and some technical challenges remain, PDOs showed great promise in the screening of novel therapy drugs. With the technical advances of high throughput, tumor-on-chip, and combined microenvironment, the drug screening process using PDOs will enhance precision care of lung cancer patients.

Efficacy of Pyrotinib With/Without Trastuzumab in Treatment-Refractory, HER2-Positive Metastatic Colorectal Cancer: Result From a Prospective Observational Study

BACKGROUND

Human epidermal growth factor receptor 2 (HER2) is a promising therapeutic target in metastatic colorectal cancer (mCRC). This study was to evaluate the efficacy and safety of pyrotinib alone or pyrotinib with trastuzumab in patients with HER2-positive mCRC.

PATIENTS AND METHODS

In this prospective observational study, patients with HER2 positive, Ras Sarcoma Viral Oncogene Homolog (RAS) wild type mCRC who received at least one standard treatment of palliative chemotherapy were enrolled. Patients were treated with oral pyrotinib alone or pyrotinib with trastuzumab. The primary endpoint was progression free survival (PFS), and the secondary endpoints were overall survival (OS), confirmed objective response rate (ORR), and safety. This trial is registered with chitcr.org, number ChiCTR2100046381.

RESULTS

From February 15, 2021, to January 10, 2023, 32 patients were enrolled in this study. Twenty (62.5%) patients were treated with pyrotinib, while 12 (37.5%) received pyrotinib and trastuzumab. As of June 24, 2023, with a median follow-up of 11.0 months, the median PFS was 5.7 months (95%CI 4.5-10.2), while OS was not evaluable (NE), ORR and disease control rate (DCR were 34.4% and 87.5%. Patients' PFS in the pyrotinib plus trastuzumab subgroup and pyrotinib monotherapy group were 8.6 and 5.5 months, OS was not evaluable (NE) and 10.9 months, ORR was 50.0% and 25.0%, respectively. Most treatment-related adverse events (TRAEs) were grade 1-2, diarrhea was the most frequent TRAE (81.3%, 26/32). Grade 3 TRAEs occurred in 11 patients: 9 for diarrhea, 1 for nausea, and 1 for oral mucositis.

CONCLUSION

Pyrotinib with or without trastuzumab showed promising anti-tumor activity and acceptable toxicities in treatment-refractory, HER2-positive mCRC.

Quantitative systems pharmacology modeling of HER2-positive metastatic breast cancer for translational efficacy evaluation and combination assessment across therapeutic modalities

HER2-positive (HER2+) metastatic breast cancer (mBC) is highly aggressive and a major threat to human health. Despite the significant improvement in patients' prognosis given the drug development efforts during the past several decades, many clinical questions still remain to be addressed such as efficacy when combining different therapeutic modalities, best treatment sequences, interindividual variability as well as resistance and potential coping strategies. To better answer these questions, we developed a mechanistic quantitative systems pharmacology model of the pathophysiology of HER2+ mBC that was extensively calibrated and validated against multiscale data to quantitatively predict and characterize the signal transduction and preclinical tumor growth kinetics under different therapeutic interventions. Focusing on the second-line treatment for HER2+ mBC, e.g., antibody-drug conjugates (ADC), small molecule inhibitors/TKI and chemotherapy, the model accurately predicted the efficacy of various drug combinations and dosing regimens at the in vitro and in vivo levels. Sensitivity analyses and subsequent heterogeneous phenotype simulations revealed important insights into the design of new drug combinations to effectively overcome various resistance scenarios in HER2+ mBC treatments. In addition, the model predicted a better efficacy of the new TKI plus ADC combination which can potentially reduce drug dosage and toxicity, while it also shed light on the optimal treatment ordering of ADC versus TKI plus capecitabine regimens, and these findings were validated by new in vivo experiments. Our model is the first that mechanistically integrates multiple key drug modalities in HER2+ mBC research and it can serve as a high-throughput computational platform to guide future model-informed drug development and clinical translation.

Patient-derived organoids in human cancer: a platform for fundamental research and precision medicine

Cancer is associated with a high degree of heterogeneity, encompassing both inter- and intra-tumor heterogeneity, along with considerable variability in clinical response to common treatments across patients. Conventional models for tumor research, such as in vitro cell cultures and in vivo animal models, demonstrate significant limitations that fall short of satisfying the research requisites. Patient-derived tumor organoids, which recapitulate the structures, specific functions, molecular characteristics, genomics alterations and expression profiles of primary tumors. They have been efficaciously implemented in illness portrayal, mechanism exploration, high-throughput drug screening and assessment, discovery of innovative therapeutic targets and potential compounds, and customized treatment regimen for cancer patients. In contrast to conventional models, tumor organoids offer an intuitive, dependable, and efficient in vitro research model by conserving the phenotypic, genetic diversity, and mutational attributes of the originating tumor. Nevertheless, the organoid technology also confronts the bottlenecks and challenges, such as how to comprehensively reflect intra-tumor heterogeneity, tumor microenvironment, tumor angiogenesis, reduce research costs, and establish standardized construction processes while retaining reliability. This review extensively examines the use of tumor organoid techniques in fundamental research and precision medicine. It emphasizes the importance of patient-derived tumor organoid biobanks for drug development, screening, safety evaluation, and personalized medicine. Additionally, it evaluates the application of organoid technology as an experimental tumor model to better understand the molecular mechanisms of tumor. The intent of this review is to explicate the significance of tumor organoids in cancer research and to present new avenues for the future of tumor research.

Positive response to trastuzumab deruxtecan in a patient with HER2-mutant NSCLC after multiple lines therapy, including T-DM1: a case report

Human epidermal growth factor 2 (HER2) mutations are uncommon in non-small cell lung cancer (NSCLC), and the lack of established, effective, targeted drugs has resulted in a persistently poor prognosis. Herein, we report the case of a non-smoking, 58-year-old man diagnosed with lung adenocarcinoma (cT3N0M1c, stage IVB) harboring a HER2 mutation (Y772_A775dupYVMA) and PD-L1 (-). The patient's Eastern Cooperative Oncology Group performance status (PS) score was assessed as 1. He commenced first-line treatment with chemotherapy, followed by immuno-chemotherapy, and with disease progression, he received HER2-targeted therapy and chemotherapy with an anti-angiogenic agent. However, HER2-targeted therapy, including pan-HER tyrosine kinase inhibitors (afatinib, pyrotinib, and pozitinib) and antibody-drug conjugate (T-DM1), produced only stable disease (SD) as the best response. After the previously described treatment, primary tumor recurrence and multiple brain metastases were observed. Despite the patient's compromised overall physical condition with a PS score of 3-4, he was administered T-DXd in addition to whole-brain radiotherapy (WBRT). Remarkably, both intracranial metastases and primary lesions were significantly reduced, he achieved a partial response (PR), and his PS score increased from 3-4 to 1. He was then treated with T-DXd for almost 9 months until the disease again progressed, and he did not discontinue the drug despite the occurrence of myelosuppression during this period. This is a critical case as it exerted an effective response to T-DXd despite multiple lines therapy, including T-DM1. Simultaneously, despite the occurrence of myelosuppression in the patient during T-DXd, it was controlled after aggressive treatment.

Non-small cell lung cancer cells with uncommon EGFR exon 19delins variants respond poorly to third-generation EGFR inhibitors

BACKGROUND

This study compared the clinical efficacy of first-, second-, and third-generation tyrosine kinase inhibitors (TKIs) in previously untreated non-small cell lung cancer (NSCLC) patients harboring uncommon epidermal growth factor receptor (EGFR) exon 19delins variants.

METHODS

We retrospectively analyzed the clinical outcomes of NSCLC patients with EGFR exon 19delins mutations who were treated with third- and first-generation EGFR TKIs. In vitro and in vivo studies were conducted to verify the sensitivity of these mutations to distinct generations of TKIs. Molecular simulation was used to investigate the structural characteristics of the EGFR mutant molecules.

RESULTS

In a multicenter cohort of 1,526 patients, 37 (2.4 %) had uncommon EGFR 19delins mutations. Twenty-four patients were treated with first-generation EGFR TKIs, and third-generation TKIs were administered to ten patients as frontline therapy. Patients carrying EGFR exon 19delins mutations who were given third-generation TKIs exhibited comparatively shorter progression-free survival (PFS) and overall survival (OS) in relation to those who received first-generation EGFR inhibitors; median PFS: 6.9 months vs. 19.1 months (p < 0.001), Median OS: 19.1 months vs. 32.6 months (p < 0.001). In vivo and in vitro studies revealed that uncommon EGFR 19delins variants exhibit limited sensitivity to third-generation EGFR inhibitors in contrast to first- and second-generation EGFR inhibitors. The molecular binding affinity of third-generation EGFR TKIs toward uncommon EGFR 19delins mutations was less than that of first- and second-generation EGFR inhibitors.

CONCLUSIONS

Uncommon EGFR 19delins variants respond poorly to third-generation EGFR inhibitors in NSCLC. Uncommon EGFR 19delins mutations may serve as an unfavorable predictive factor for the efficacy of third-generation EGFR TKI therapy, offering potential guidance for future clinical decision-making.

HER2 Alterations in Non-Small Cell Lung Cancer: Biologico-Clinical Consequences and Interest in Therapeutic Strategies

Lung cancer stands as the first cause of death by cancer in the world. Despite the improvement in patients' outcomes in the past decades through the development of personalized medicine approaches, a substantial portion of patients remains ineligible for targeted therapies due to the lack of a "druggable" molecular target. HER2, a receptor tyrosine kinase member of the EGFR/ErbB family, is known to show oncogenic properties. In this review, we focus on the different HER2 dysregulation mechanisms that have been observed in non-small cell lung cancer (NSCLC): gene mutation, gene amplification, protein overexpression and protein hyper-phosphorylation, the latter suggesting that HER2 dysregulation can occur independently of any molecular aberration. These HER2 alterations inevitably have consequences on tumor biology. Here, we discuss how they are not only involved in abnormal proliferation and survival of cancer cells but also potentially in increased angiogenic properties, mesenchymal features and tumor immune escape. Finally, we review the impact of these HER2 alterations in various therapeutic approaches. While standard chemotherapy and groundbreaking immunotherapy seem rather ineffective for HER2-altered NSCLCs, the development of HER2-targeted therapies such as tyrosine kinase inhibitors, anti-HER2 antibodies and especially antibody-drug conjugates could provide new hopes for patients.

Applications of lung cancer organoids in precision medicine: from bench to bedside

As the leading cause of cancer-related mortality, lung cancer continues to pose a menacing threat to human health worldwide. Lung cancer treatment options primarily rely on chemoradiotherapy, surgery, targeted therapy, or immunotherapy. Despite significant progress in research and treatment, the 5-year survival rate for lung cancer patients is only 10-20%. There is an urgent need to develop more reliable preclinical models and valid therapeutic approaches. Patient-derived organoids with highly reduced tumour heterogeneity have emerged as a promising model for high-throughput drug screening to guide treatment of lung cancer patients. Organoid technology offers a novel platform for disease modelling, biobanking and drug development. The expected benefit of organoids is for cancer patients as the subsequent precision medicine technology. Over the past few years, numerous basic and clinical studies have been conducted on lung cancer organoids, highlighting the significant contributions of this technique. This review comprehensively examines the current state-of-the-art technologies and applications relevant to the formation of lung cancer organoids, as well as the potential of organoids in precision medicine and drug testing. Video Abstract.

Management of HER2 alterations in non-small cell lung cancer - The past, present, and future

HER2 mutations, which account for 2-4% of non-small cell lung cancer (NSCLC), are distinct molecular alterations identified via next generation sequencing (NGS). Previously, treatment outcomes in HER2-mutant metastatic NSCLC were dismal, showing limited clinical benefit with platinum-based chemotherapy with or without immunotherapy. In contrast to HER2-altered breast and gastric cancer, HER2-mutant NSCLC does not benefit from HER2 targeting agents such as trastuzumab or TDM1. HER2 mutations are also inherently different from HER2 overexpression and amplification. Currently, trastuzumab deruxtecan, a HER2 targeting antibody drug conjugate (ADC) is the first and only approved treatment option for patients with HER2-mutant metastatic NSCLC after failure with standard treatment. In this review, we summarized the biology of HER2 and detection of HER2 overexpression, amplification and mutations, as well as general landscape of landmark and ongoing clinical trials encompassing from chemotherapy to targeted agents, including tyrosine kinase inhibitors (TKIs), ADCs and investigational agents.

Efficacy of anti-HER2 drugs in the treatment of patients with HER2-mutated cancers: a systematic review and meta-analysis

Anti-human epidermal growth factor receptor-2 (anti-HER2) therapy has shown excellent efficacy in patients with HER2 overexpression and amplification. Although HER2 mutations are rarely expressed in several cancers, when they occur, they can activate the HER2 signaling pathway. In recent years, studies have shown that anti-HER2 drugs have promising efficacy in patients with HER2 mutations. Based on keywords, we searched databases, such as PubMed, Embase, and Cochrane Library, and the main conference abstracts. We extracted data on objective response rate (ORR), clinical benefit rate (CBR), duration of response (DOR), progression-free survival (PFS), and overall survival (OS) from studies on the efficacy of anti-HER2 therapies in patients with HER2-mutated cancers, and analyzed grade 3 or higher adverse events (AEs). We included 19 single-arm clinical studies and 3 randomized controlled trials (RCTs), containing a total of 1017 patients with HER2 mutations, involving seven drugs and nine cancers, and 18 studies enrolled a high proportion of heavily pretreated patients who had received multiple lines of therapy. Our results showed pooled ORR and CBR of 25.0% (range, 3.8-72.7%; 95% CI, 18-32%) and 36.0% (range, 8.3-63.0%; 95% CI, 31-42%) for anti-HER2 therapy in HER2-mutated cancers. The pooled median PFS, OS, DOR were 4.89 (95% CI, 4.16-5.62), 12.78 (95% CI, 10.24-15.32), and 8.12 (95% CI, 6.48-9.75) months, respectively. In a subgroup analysis, we analyzed the ORR for different cancers, showing 27.0, 25.0, 23.0, and 16.0% for breast, lung, cervical, and biliary tract cancers, respectively. ORR analyses were performed for different drugs as monotherapy or in combination, showing 60.0% for trastuzumab deruxtecan (T-DXd), 31.0% for pyrotinib, 26.0% for neratinib combined with trastuzumab, 25.0% for neratinib combined with fulvestrant, 19.0% for trastuzumab combined with pertuzumab, and 16.0% for neratinib. In addition, we found that diarrhoea, neutropenia, and thrombocytopenia were the most common grade ≥ 3 AEs associated with anti-HER2 therapeutic agents. In this meta-analysis of heavily pretreated patients with HER2 mutations, anti-HER2 therapies, DS-8201 and trastuzumab emtansine, showed promising efficacy and activity. Anti-HER2 therapies showed different efficacies in different or the same cancer settings and all had a tolerable safety profile.

The History and Development of HER2 Inhibitors

HER2 is highly expressed in a variety of malignant tumors and affects the prognosis of patients, making it a highly sensitive target for cancer therapy. Since the approval of the first HER2 inhibitor, trastuzumab, in 1998, HER2-targeted drugs have rapidly evolved. Currently, targeting HER2 drugs mainly include monoclonal antibodies (mAbs), tyrosine kinase inhibitors (TKIs), and antibody-drug conjugates (ADCs). This article reviews the development of HER2 inhibitors for various tumors over the past 20 years.

Understanding the feasibility of chemotherapeutic and immunotherapeutic targets against non-small cell lung cancers: an update of resistant responses and recent combinatorial therapies

Despite consistent progress in prompt diagnosis and curative therapies in the last decade, lung cancer (LC) continues to threaten mankind, accounting for nearly twice the casualties compared to prostate, breast, and other cancers. Statistics associate ~25% of 2021 cancer-related deaths with LC, more than 80% of which are explicitly caused by tobacco smoking. Prevailing as small and non-small cell pathologies, with respective occurring frequency of nearly 15% and 80-85%, non-small cell LCs (NSCLCs) are prominently distinguished into lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC), subtypes. Since the first use of epidermal growth factor receptor (EGFR) inhibitor gefitinib for NSCLC treatment in 2002, immense progress has been made for targeted therapies with the next generation of drugs spanning across the chronological generations of small molecule inhibitors. The last two years have overseen the clinical approval of more than 10 therapeutic agents as first-line NSCLC medications. However, uncertain mutational aberrations as well as systemic resistant responses, and abysmal overall survival curtail the combating efficacies. Of late, immune checkpoint inhibitors (ICIs) against various molecules including programmed cell death-1 (PD-1) and its ligand (PD-L1) have been demonstrated as reliable LC treatment targets. Keeping these aspects in mind, this review article discusses the success of NSCLC chemo and immunotherapies with their characteristic effectiveness and future perspectives.

Recent advances in non-small cell lung cancer targeted therapy; an update review

Lung cancer continues to be the leading cause of cancer-related death worldwide. In the last decade, significant advancements in the diagnosis and treatment of lung cancer, particularly NSCLC, have been achieved with the help of molecular translational research. Among the hopeful breakthroughs in therapeutic approaches, advances in targeted therapy have brought the most successful outcomes in NSCLC treatment. In targeted therapy, antagonists target the specific genes, proteins, or the microenvironment of tumors supporting cancer growth and survival. Indeed, cancer can be managed by blocking the target genes related to tumor cell progression without causing noticeable damage to normal cells. Currently, efforts have been focused on improving the targeted therapy aspects regarding the encouraging outcomes in cancer treatment and the quality of life of patients. Treatment with targeted therapy for NSCLC is changing rapidly due to the pace of scientific research. Accordingly, this updated study aimed to discuss the tumor target antigens comprehensively and targeted therapy-related agents in NSCLC. The current study also summarized the available clinical trial studies for NSCLC patients.

Potential mechanism of pyrotinib-induced diarrhea was explored by gut microbiome and ileum metabolomics

Pyrotinib is a novel epidermal growth factor receptor/human epidermal growth factor receptor-2 (HER2) tyrosine kinase inhibitor that exhibited clinical efficacy in patients with HER2-positive breast cancer and HER2-mutant/amplified lung cancer. However, severe diarrhea adverse responses preclude its practical use. At present, the mechanism of pyrotinib-induced diarrhea is unknown and needs further study. First, to develop a suitable and reproducible animal model, we compared the effects of different doses of pyrotinib (20, 40, 60 and 80 mg/kg) in Wistar rats. Second, we used this model to examine the intestinal toxicity of pyrotinib. Finally, the mechanism underlying pyrotinib-induced diarrhea was fully studied using gut microbiome and host intestinal tissue metabolomics profiling. Reproducible diarrhea occurred in rats when they were given an 80 mg/kg daily dose of pyrotinib. Using the pyrotinib-induced model, we observed that Lachnospiraceae and Acidaminococcaceae decreased in the pyrotinib groups, whereas Enterobacteriaceae, Helicobacteraceae and Clostridiaceae increased at the family level by 16S rRNA gene sequence. Multiple bioinformatics methods revealed that glycocholic acid, ursodeoxycholic acid and cyclic AMP increased in the pyrotinib groups, whereas kynurenic acid decreased, which may be related to the pathogenesis of pyrotinib-induced diarrhea. Additionally, pyrotinib-induced diarrhea may be associated with a number of metabolic changes mediated by the gut microbiome, such as Primary bile acid biosynthesis. We reported the establishment of a reproducible pyrotinib-induced animal model for the first time. Furthermore, we concluded from this experiment that gut microbiome imbalance and changes in related metabolites are significant contributors to pyrotinib-induced diarrhea.

Molecular correlation of response to pyrotinib in advanced NSCLC with HER2 mutation: biomarker analysis from two phase II trials

BACKGROUND

Non-small cell lung cancer (NSCLC) with HER2 mutation has entered into the era of targeted therapy. However, both anti-HER2 antibody-drug conjugates (ADCs) and tyrosine kinase inhibitors (TKIs) showed moderate objective response rate (ORR) and median progression-free survival (PFS). The aim of this study was to investigate the molecular features of responders to pyrotinib in advanced NSCLC with HER2 mutation.

METHODS

Patients from our two previous phase II trials were pooled analyzed. Their circulating tumor DNA (ctDNA) were detected by next-generation sequencing (NGS) panels, and the correlation with the efficacy of pyrotinib was investigated.

RESULTS

This pooled analysis included 75 patients, and 50 of them with baseline plasma samples were finally enrolled with a median age of 57 years old. The overall ORR and median PFS were 28% and 7.0 months respectively. Biomarker analysis showed that 5 patients were ctDNA nonshedding. Patients with TP53 wild type were significantly associated with higher disease control rate (97.1%vs. 68.8%, p = 0.010), PFS (median 8.4 vs. 2.8 months, p = 0.001) and overall survival (OS, median 26.7 vs. 10.4 months, p < 0.001) than those with mutations. ctDNA of nonshedding and clearance exhibited significantly longer PFS (median: 10.2 vs. 9.8 vs. 5.6 months, p = 0.036) and a trend of longer OS (median: 35.3 vs. 18.1 vs. 14.6 months, p = 0.357) than those not.

CONCLUSION

Patients with TP53 wild type, ctDNA nonshedding, or clearance showed superior efficacy of pyrotinib in patients with HER2-mutated advanced NSCLC, which might be helpful to guide the utility of pyrotinib in clinical setting.

TRIAL REGISTRATION

The patients were from two registered clinical trials (ClinicalTrials.gov: NCT02535507, NCT02834936).

EGFR and ERBB2 exon 20 insertion/duplication in advanced non-small cell lung cancer: genomic profiling and clinicopathologic features

Background

Exon 20 (ex20) in-frame insertions or duplications (ins/dup) in epidermal growth factor receptor (EGFR) and its analog erb-b2 receptor tyrosine kinase 2 (ERBB2) are each detected in 1.5% of non-small cell lung cancer (NSCLC). Unlike EGFR p.L858R or ex19 deletions, ex20 ins/dup is associated with de novo resistance to classic EGFR inhibitors, lack of response to immune checkpoint inhibitors, and poor prognosis. US Food and Drug Administration has approved mobocertinib and amivantamab for targeting tumors with this aberration, but the number of comprehensive studies on ex20 ins/dup NSCLC is limited. We identified 18 cases of NSCLCs with EGFR/ERBB2 ex20 ins/dup and correlated the findings with clinical and morphologic information including programed death-ligand 1 (PD-L1) expression.

Methods

A total of 536 NSCLC cases tested at our institution between 2014 and 2023 were reviewed. A custom-designed 214-gene next-generation sequencing panel was used for detecting DNA variants, and the FusionPlex CTL panel (ArcherDx) was used for the detection of fusion transcripts from formalin-fixed, paraffin-embedded tissue. Immunohistochemistry (IHC)for PD-L1 was performed using 22C3 or E1L3N clones.

Results

Nine EGFR and nine ERBB2 ex20 ins/dup variants were identified from an equal number of men and women, 14 were non- or light smokers, and 15 had stage IV disease. All 18 cases were adenocarcinomas. Seven of the 11 cases with available primary tumors had acinar predominant pattern, two had lepidic predominant pattern, and the remainder had papillary (one case) and mucinous (one case) patterns. Ex20 ins/dup variants were heterogenous in-frame one to four amino acids spanning A767-V774 in EGFR and Y772-P780 in ERBB2 and were clustered in the loop following the C-helix and α C-helix. Twelve cases (67%) had co-existing TP53 variants. Copy number variation in CDK4 amplification was identified in one case. No fusion or microsatellite instability was identified in any case. PD-L1 was positive in two cases, low positive in four cases, and negative in 11 cases.

Conclusions

NSCLCs harboring EGFR/ERBB2 ex20 ins/dup are rare and tend to be acinar predominant, negative for PD-L1, more frequent in non- or light smokers, and mutually exclusive with other driver mutations in NSCLC. The correlation of different EGFR/ERBB2 ex20 ins/dup variants and co-existing mutations with response to targeted therapy and the possibility of developing resistant mutations after mobocertinib treatment warrants further investigation.

Dramatic Response to Pyrotinib and T-DM1 in HER2-Negative Metastatic Breast Cancer With 2 Activating HER2 Mutations

HER2 signaling is activated in response to somatic HER2 mutations, which are often found in invasive lobular breast cancer (ILC) and are associated with poor prognosis. Tyrosine kinase inhibitors (TKIs) have demonstrated considerable antitumor activity in patients with HER2-mutated advanced breast cancer (BC). Further, several clinical trials have indicated that HER2-targeted antibody-drug conjugates (ADCs) exhibit promising efficacy in lung cancer with HER2 mutations, and the efficacy of ADCs against HER2-mutated BC is currently being evaluated. Several preclinical studies have demonstrated that the therapeutic efficacy of ADCs in HER2-mutated cancer can be enhanced by the addition of irreversible TKIs, but the potential of such a combined treatment regimen for the treatment of HER2-mutated BC has not been reported. Herein, we describe a case in which a patient with estrogen receptor-positive/HER2-negative metastatic ILC with 2 activating HER2 mutations (D769H and V777L) exhibited a significant and durable response to anti-HER2 treatment with pyrotinib (an irreversible TKI) in combination with ado-trastuzumab emtansine, which was administered after multiple lines of therapy that had resulted in disease progression. Further, based on the evidence from the present case, TKI plus ADC seems to be a promising combination anti-HER2 regimen for patients with HER2-negative/HER2-mutated advanced BC, although further rigorous studies are warranted to confirm these findings.

Genomic landscape and efficacy of HER2-targeted therapy in patients with HER2-mutant non-small cell lung cancer

Background

HER2-targeted therapy provides survival benefits to HER2-mutant non-small cell lung cancer (NSCLC). A better understanding of the clinical and genomic characterization of treatment-naïve HER2-positive NSCLC, as well as the efficacy of and resistance to HER2-targeted therapy in HER2-altered NSCLC, could promote further improvement of HER2 targeted therapy.

Methods

HER2-altered NSCLC patients was retrospectively included and their genomic profiles were performed by next-generation sequencing. The clinical outcomes included overall response rate, disease control rate and progression-free survival.

Results

Among 176 treatment-naïve patients with HER2 alterations, 64.8% harbored HER2 mutations with/without HER2 amplification, and 35.2% carried HER2 amplification only. Molecular characterization was correlated with tumor stage that late-stage NSCLC with HER2 oncogenic mutations showed a higher prevalence of TP53 mutations and a higher tumor mutation burden. However, this correlation was not found in patients with HER2 amplification only. Twenty-one patients with HER2 alterations treated with pyrotinib or afatinib were retrospectively enrolled. Pyrotinib yielded a longer median progression-free survival than afatinib (5.9 [95% CI, 3.8-13.0] vs. 4.0 months [95% CI, 1.9-6.3], P = 0.06) in these patients. Analysis of the genomic profiles before and after anti-HER2 targeted therapies identified de novo HER2 copy number gain and G518W mutation, as well as mutations involving DNA damage repair signaling, SWI–SNF complex, and epigenetic regulations as potential resistance mechanisms.

Conclusion

HER2-mutant NSCLC had different molecular features from HER2-amplified NSCLC, and its genomic profile was dependent of tumor stage. Pyrotinib had superior therapeutic effects than afatinib in HER2-altered NSCLC, although larger cohorts are warranted to validate it. HER2-dependent and -independent resistance mechanisms to afatinib and pyrotinib were unveiled.

The application of patient-derived organoid in the research of lung cancer

Lung cancer is the most common cancer and the leading cause of cancer-related death worldwide. However, mechanisms of its progression remained unclear and new treatments against this disease are rapidly emerging. As a novel preclinical model, patient-derived organoid (PDO) can also be established from the patient's tumor tissue and cultured in the laboratory, which preserves the key biological characteristics of the original tumor. Compared to the patient-derived xenograft (PDX) model of lung cancer, the culture success rate is improved, and the time and cost of model establishment are largely reduced. PDO is also expected to provide a more individual model to predict the efficacy of anti-cancer treatment in vitro. This paper summarizes the current application of PDO in the translational research of lung cancer.

Landscape of the clinical development of China innovative anti-lung cancer drugs

Even today, lung cancer remains one of the most frequently diagnosed cancers and the leading cause of cancer-related deaths worldwide. Throughout the past decades, remarkable advances have been made in the research and development of anti-lung cancer drugs in China. Since the first registered Chinese clinical trial on May 2, 2006, many potent anti-lung cancer drugs have been developed and approved by the China Food and Drug Administration and the National Medical Product Administration of China. Among them, the most advance were observed in the development of targeted agents and immunotherapeutic agents such as epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) icotinib, aumolertinib, and furmonertinib, anaplastic lymphoma kinase (ALK)-TKI ensartinib, programmed cell death-1 (PD-1) monoclonal antibodies (mAbs) camrelizumab, sintilimab, and tislelizumab, and programmed cell death-ligand 1 (PD-L1) mAb sugemalimab, which have made huge breakthrough in recent years. Some other investigational innovative drug also demonstrated promising efficacy and acceptable safety profiles. Results from clinical studies on these China innovative drugs have led to changes in clinical practice guidelines and considerably improved the outcomes for patients with lung cancer. Thus, in this review, we aim to provide further insight into the clinical development and achievement of China innovative anti-lung cancer drugs.

Case report: Long-term clinical benefit of pyrotinib therapy following trastuzumab resistance in HER2-amplification recurrent mucinous ovarian carcinoma

Advanced or recurrent mucinous carcinoma of the ovary minimally responds to current cytotoxic treatments and has a poor prognosis. Despite multimodal treatment with chemotherapy and surgery, most patients ultimately progress and require palliative systemic therapy. Anti-HER2 therapy has been demonstrated to be an effective strategy for the treatment of HER2-positive breast cancer. However, the role of anti-HER2 therapy in ovarian cancer remains largely unknown. Here, we report the case of a young woman with FIGO Stage IIIc recurrent mucinous ovarian carcinoma (MOC) who developed trastuzumab resistance and disease progression following cross-treatment with trastuzumab combined with pertuzumab. HER2 amplification was discovered using next-generation sequencing (NGS). The patient then received bevacizumab, and pyrotinib (an irreversible HER2 antagonist) plus capecitabine treatment, and achieved a long-term clinical benefit for 22 months. Pyrotinib combined with bevacizumab is a potential treatment for MOC patients who are heavily pretreated and harbor a HER2 amplification. Our case may provide valuable treatment information for patients with advanced or recurrent MOC.

Organoid technology and applications in lung diseases: Models, mechanism research and therapy opportunities

The prevalency of lung disease has increased worldwide, especially in the aging population. It is essential to develop novel disease models, that are superior to traditional models. Organoids are three-dimensional (3D) in vitro structures that produce from self-organizing and differentiating stem cells, including pluripotent stem cells (PSCs) or adult stem cells (ASCs). They can recapitulate the in vivo cellular heterogeneity, genetic characteristics, structure, and functionality of original tissues. Drug responses of patient-derived organoids (PDOs) are consistent with that of patients, and show correlations with genetic alterations. Thus, organoids have proven to be valuable in studying the biology of disease, testing preclinical drugs and developing novel therapies. In recent years, organoids have been successfully applied in studies of a variety of lung diseases, such as lung cancer, influenza, cystic fibrosis, idiopathic pulmonary fibrosis, and the recent severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic. In this review, we provide an update on the generation of organoid models for these diseases and their applications in basic and translational research, highlighting these signs of progress in pathogenesis study, drug screening, personalized medicine and immunotherapy. We also discuss the current limitations and future perspectives in organoid models of lung diseases.

Molecular and clinicopathological characteristics of ERBB2 gene fusions in 32,131 Chinese patients with solid tumors

ERBB2 amplification is one of the most important and mature targets for HER2-targeted drug therapy. Somatic mutations of ERBB2 in the tyrosine kinase domain have been studied extensively, and play a role in response to anti-HER2 therapy among different cancer types. However, ERBB2 fusion has not been got attention and its relevance to HER2-targeted therapy is unclear. We comprehensively characterized ERBB2 fusions from next-generation sequencing (NGS) data between May 2018 and October 2021 in 32,131 various solid tumors. Among the tumors, 0.28% harbored ERBB2 fusions, which occurred more commonly in gastroesophageal junction cancer (3.12%; 3/96), breast cancer (1.89%; 8/422), urothelial carcinoma (1.72%; 1/58), and gastric cancer (1.60%; 23/1,437). Our population presented with a median age of 65 years (range 28 to 88 years), a high proportion of men (55 men vs 34 women; 61.80%). Among the patients with ERBB2 fusions, TP53 (82%), APC (18%), and CDK4 (15%) were the top3 co-mutant genes. What’s more, most patients with ERBB2 fusion also had ERBB2 amplification (75.28%; 67/89), which was similar to the data in the TCGA database (88.00%; 44/50). Furthermore, TCGA database shows that patients with ERBB2 fusions in pan-cancer had a worse prognosis than those without ERBB2 fusions, as well as in breast cancer. Besides, ERBB2 amplification combined with ERBB2 fusion had worse prognosis than those with only ERBB2 amplification. ERBB2 fusion may interfere the effect of anti-HER2-targeted antibody drugs and influence the prognosis of patients with ERBB2 amplification. Prospective clinical trials are warranted to confirm the results in the future.

Deciphering the Impact of HER2 Alterations on Non-Small-Cell Lung Cancer: From Biological Mechanisms to Therapeutic Approaches

Despite the recent increase in the number of types of treatments, non-small-cell lung cancer (NSCLC) remains the major cause of death from cancer worldwide. So, there is an urgent need to develop new therapeutic strategies. The HER2 gene codes for tyrosine kinase receptor whose alterations are known to drive carcinogenesis. HER2 alterations, including amplification, mutations, and overexpression, have been mainly described in breast and gastric cancers, but up to 4% of NSCLC harbor actionable HER2 mutations. HER2-targeted therapy for NSCLC with trastuzumab, pertuzumab, and trastuzumab emtansine has failed to demonstrate an improvement in survival. Nevertheless, recent data from phase II trials have shed light on promising specific therapies for HER2-mutant NSCLC such as trastuzumab deruxtecan. Herein, we aimed to provide an updated review on the biology, epidemiology, molecular testing, and therapeutic strategies for NSCLC with HER2 molecular alterations.

Response to Pyrotinib in a Patient with Metastatic Bladder Urothelial Carcinoma Harboring HER2 V842I Mutation: A Case Report

Background

The highest incidence of human epidermal growth factor receptor 2 (HER2) mutations has been observed in bladder cancer (BC). However, the function of HER2 mutation in tumor progression and metastasis remains unclear. Currently, no responses to the pan-HER kinase inhibitor were observed in HER2-mutant BC.

Case Presentation

We described a patient with metastatic bladder urothelial carcinoma (BUC) carrying a HER2 V842I mutation both in circulating tumor DNA (ctDNA) and biopsy sample. The patient was then treated with a HER2 tyrosine kinase inhibitor, pyrotinib, and responded well. However, the targeting treatment was terminated due to G3 diarrhea. Reduced dose of pyrotinib was later added to late-line treatment, the patient’s tumor again responded with a significant decrease in CA199.

Conclusion

This is the first reported case of HER2 V842I mutation successfully treated with pyrotinib in BUC, suggesting pyrotinib therapy might serve as a therapeutic option for BUC patients harboring HER2 activating mutation.

HER2 in Non-Small Cell Lung Cancer: A Review of Emerging Therapies

Simple Summary

There are growing data on targeting HER2 alterations, which include gene mutations, gene amplifications, and protein overexpression, for non-small cell lung cancer (NSCLC). Currently, there are limited targeted therapies approved for NSCLC patients with HER2 alterations, and this remains an unmet clinical need. There has been an influx of research on antibody–drug conjugates, monoclonal antibodies, and tyrosine kinase inhibitors. This review discusses the diagnostic challenges of HER2 alterations in NSCLC and summarizes recent progress in HER2 targeted drugs for both clinicians and researchers treating this patient population.

Abstract

Human epidermal growth factor receptor 2 (HER2), a member of the ERBB family of tyrosine kinase receptors, has emerged as a therapeutic target of interest for non-small cell lung cancer (NSCLC) in recent years. Activating HER2 alterations in NSCLC include gene mutations, gene amplifications, and protein overexpression. In particular, the HER2 exon 20 mutation is now a well clinically validated biomarker. Currently, there are limited targeted therapies approved for NSCLC patients with HER2 alterations. This remains an unmet clinical need, as HER2 alterations are present in 7–27% of de novo NSCLC and may serve as a resistance mechanism in up to 10% of EGFR mutated NSCLC. There has been an influx of research on antibody–drug conjugates (ADCs), monoclonal antibodies, and tyrosine kinase inhibitors (TKIs) with mixed results. The most promising therapies are ADCs (trastuzumab-deruxtecan) and novel TKIs targeting exon 20 mutations (poziotinib, mobocertinib and pyrotinib); both have resulted in meaningful anti-tumor efficacy in HER2 mutated NSCLC. Future studies on HER2 targeted therapy will need to define the specific HER2 alteration to better select patients who will benefit, particularly for HER2 amplification and overexpression. Given the variety of HER2 targeted drugs, sequencing of these agents and optimizing combination therapies will depend on more mature efficacy data from clinical trials and toxicity profiles. This review highlights the challenges of diagnosing HER2 alterations, summarizes recent progress in novel HER2-targeted agents, and projects next steps in advancing treatment for the thousands of patients with HER2 altered NSCLC.

Ex situ-armus: experimental models for combating respiratory dysfunction

Ex situ experimental models have become a main stay in pulmonary research. Organoids and explant systems have uncovered novel stem cell subsets, served as disease models, delineated cell fate transitions, and aided high throughput pre-clinical drug screening. Integration of gene-editing and bioengineering approaches have further generated novel avenues for regenerative medicine and transplantation strategies. In this article, we highlight recent studies, aided by ex situ systems, which have contributed to significant advances in our understanding of the human lower respiratory tract. We present key observations from these studies to gain improved insights into human disease. We conclude this article with a summary of existing challenges and potential technological advances to successfully mirror human tissue physiology.

Lung Cancer Organoids: The Rough Path to Personalized Medicine

Simple Summary

Lung cancer is very difficult to cure, especially when it has spread to other parts of the body. One of the main reasons that delay the identification of effective therapies is the complexity of lung cancer cells, which can be very different among individual patients. Organoids are small aggregates of tumor cells that are generated from lung tumors and used in cancer research laboratories to study the features of tumor cells. Organoids have unique properties, as they reproduce many characteristics of the tumor derived from each specific patient. Due to their capacity to reproduce individual tumor features in the laboratory setting, organoids are an excellent system to study lung cancer and to identify functional therapies. This review summarizes the challenges encountered by researchers in the field of lung cancer organoids and describes how the advances in organoid technology may allow the future development of individualized therapies for lung cancer patients.

Abstract

Lung cancer is the leading cause of cancer death worldwide. Despite significant advances in research and therapy, a dismal 5-year survival rate of only 10–20% urges the development of reliable preclinical models and effective therapeutic tools. Lung cancer is characterized by a high degree of heterogeneity in its histology, a genomic landscape, and response to therapies that has been traditionally difficult to reproduce in preclinical models. However, the advent of three-dimensional culture technologies has opened new perspectives to recapitulate in vitro individualized tumor features and to anticipate treatment efficacy. The generation of lung cancer organoids (LCOs) has encountered greater challenges as compared to organoids derived from other tumors. In the last two years, many efforts have been dedicated to optimizing LCO-based platforms, resulting in improved rates of LCO production, purity, culture timing, and long-term expansion. However, due to the complexity of lung cancer, further advances are required in order to meet clinical needs. Here, we discuss the evolution of LCO technology and the use of LCOs in basic and translational lung cancer research. Although the field of LCOs is still in its infancy, its prospective development will likely lead to new strategies for drug testing and biomarker identification, thus allowing a more personalized therapeutic approach for lung cancer patients.

Resistance to TKIs in EGFR-Mutated Non-Small Cell Lung Cancer: From Mechanisms to New Therapeutic Strategies

Simple Summary

Resistance to tyrosine kinase inhibitors (TKIs) of the epidermal growth factor receptor (EGFR) in advanced mutant non-small cell lung cancer (NSCLC) constitutes a therapeutic challenge. Resistance may occur as a result of EGFR-dependent and independent molecular pathways. The first commonly includes T790M, C797S, L792X and L718X mutations, while the latter pertains to HER2 and MET amplifications, gene rearrangements, disruption in PIK3CA, MAPK signaling and SCLC and epithelial–mesenchymal cells transformation. Liquid biopsies detecting mutant cell-free DNA (cfDNA) have a major potential in the detection of mutant clones before they become clinically apparent. Newer-generation TKIs, bispecific antibodies and antibody-drug conjugates or combinations of TKIs with other TKIs or chemotherapy, immunotherapy and anti-vascular endothelial growth factors (anti-VEGFs) are currently in use or under investigation in EGFR mutant NSCLC. In EGFR mutant NSCLC metastatic to the brain, the blood–brain barrier (BBB) decreases the ability of TKIs to reach the central nervous system (CNS), acting as an additional resistance factor, which can presently be addressed with osimertinib. The potential of rechallenging EFGR TKIs after chemotherapy and combining it with anti-PD-1 immunotherapeutics remains ambivalent. Harnessing nanocarriers to improve drug delivery in EGFR TKIs-resistant NSCLC has been promising in preclinical settings, but it is yet to be determined in a clinical context.

Abstract

Resistance to tyrosine kinase inhibitors (TKIs) of the epidermal growth factor receptor (EGFR) in advanced mutant Non-Small Cell Lung Cancer (NSCLC) constitutes a therapeutic challenge. This review intends to summarize the existing knowledge about the mechanisms of resistance to TKIs in the context of EGFR mutant NSCLC and discuss its clinical and therapeutic implications. EGFR-dependent and independent molecular pathways have the potential to overcome or circumvent the activity of EGFR-targeted agents including the third-generation TKI, osimertinib, negatively impacting clinical outcomes. CNS metastases occur frequently in patients on EGFR-TKIs, due to the inability of first and second-generation agents to overcome both the BBB and the acquired resistance of cancer cells in the CNS. Newer-generation TKIs, TKIs targeting EGFR-independent resistance mechanisms, bispecific antibodies and antibody-drug conjugates or combinations of TKIs with other TKIs or chemotherapy, immunotherapy and Anti-Vascular Endothelial Growth Factors (anti-VEGFs) are currently in use or under investigation in EGFR mutant NSCLC. Liquid biopsies detecting mutant cell-free DNA (cfDNA) provide a window of opportunity to attack mutant clones before they become clinically apparent. Overall, EGFR TKIs-resistant NSCLC constitutes a multifaceted therapeutic challenge. Mapping its underlying mutational landscape, accelerating the detection of resistance mechanisms and diversifying treatment strategies are essential for the management of the disease.

NSCLC as the Paradigm of Precision Medicine at Its Finest: The Rise of New Druggable Molecular Targets for Advanced Disease

Standard treatment for advanced non-small cell lung cancer (NSCLC) historically consisted of systemic cytotoxic chemotherapy until the early 2000s, when precision medicine led to a revolutionary change in the therapeutic scenario. The identification of oncogenic driver mutations in EGFR, ALK and ROS1 rearrangements identified a subset of patients who largely benefit from targeted agents. However, since the proportion of patients with druggable alterations represents a minority, the discovery of new potential driver mutations is still an urgent clinical need. We provide a comprehensive review of the emerging molecular targets in NSCLC and their applications in the advanced setting.

ESMO recommendations on the use of circulating tumour DNA assays for patients with cancer: a report from the ESMO Precision Medicine Working Group

Circulating tumour DNA (ctDNA) assays conducted on plasma are rapidly developing a strong evidence base for use in patients with cancer. The European Society for Medical Oncology convened an expert working group to review the analytical and clinical validity and utility of ctDNA assays. For patients with advanced cancer, validated and adequately sensitive ctDNA assays have utility in identifying actionable mutations to direct targeted therapy, and may be used in routine clinical practice, provided the limitations of the assays are taken into account. Tissue based testing remains the preferred test for many cancer patients, due to limitations of ctDNA assays detecting fusion events and copy number changes, although ctDNA assays may be routinely used when faster results will be clinically important, or when tissue biopsies are not possible or inappropriate. Reflex tumour testing should be considered following a non-informative ctDNA result, due to false negative results with ctDNA testing. In patients treated for early-stage cancers, detection of molecular residual disease (MRD) or molecular relapse (MR), has high evidence of clinical validity in anticipating future relapse in many cancers. MRD/MR detection cannot be recommended in routine clinical practice, as currently there is no evidence for clinical utility in directing treatment. Additional potential applications of ctDNA assays, under research development and not recommended for routine practice, include identifying patients not responding to therapy with early dynamic changes in ctDNA levels, monitoring therapy for the development of resistance mutations prior to clinical progression, and in screening asymptomatic people for cancer. Recommendation for reporting of results, future development of ctDNA assays, and future clinical research are made.

Pyrotinib for HER2-amplified non-small cell lung cancer patient after progression to Afatinib: a case report

Contrary to the success of antihuman epidermal growth factor receptor 2 (HER2) therapy in HER2-amplified breast cancer, the optimal targeted drug therapy for HER2-amplified lung cancer remains to be determined clinically. In this report, a nonsmoker, Chinese, old, male patient was diagnosed with cT2bN3M0 nonsmall cell lung cancer with genetic testing revealing HER2 amplification. Though the patient received successful microwave ablation, the results of reexamination after two cycles of afatinib monotherapy showed disease progression. Then the treatment regimen was switched to pan-HER inhibitor pyrotinib 400 mg daily, with which the patient remained with stable disease for 9 months. After computed tomography showed tumor enlargement in October 2021, anlotinib was added to the present treatment. This case suggests that pyrotinib may provide a novel effective treatment option for HER2-amplified lung cancer.

Tumor organoids: applications in cancer modeling and potentials in precision medicine

Cancer is a top-ranked life-threatening disease with intratumor heterogeneity. Tumor heterogeneity is associated with metastasis, relapse, and therapy resistance. These factors contribute to treatment failure and an unfavorable prognosis. Personalized tumor models faithfully capturing the tumor heterogeneity of individual patients are urgently needed for precision medicine. Advances in stem cell culture have given rise to powerful organoid technology for the generation of in vitro three-dimensional tissues that have been shown to more accurately recapitulate the structures, specific functions, molecular characteristics, genomic alterations, expression profiles, and tumor microenvironment of primary tumors. Tumoroids in vitro serve as an important component of the pipeline for the discovery of potential therapeutic targets and the identification of novel compounds. In this review, we will summarize recent advances in tumoroid cultures as an excellent tool for accurate cancer modeling. Additionally, vascularization and immune microenvironment modeling based on organoid technology will also be described. Furthermore, we will summarize the great potential of tumor organoids in predicting the therapeutic response, investigating resistance-related mechanisms, optimizing treatment strategies, and exploring potential therapies. In addition, the bottlenecks and challenges of current tumoroids will also be discussed in this review.

HER2-Altered Non-Small Cell Lung Cancer: Biology, Clinicopathologic Features, and Emerging Therapies

Multiple oncogenic molecular alterations have been discovered that serve as potential drug targets in non-small cell lung cancer (NSCLC). While the pathogenic and pharmacological features of common targets in NSCLC have been widely investigated, those of uncommon targets are still needed to be clarified. Human epidermal growth factor receptor 2 (HER2, ERBB2)-altered tumors represent a highly heterogeneous group of diseases, which consists of three distinct situations including mutation, amplification and overexpression. Compared with breast and gastric cancer, previous studies have shown modest and variable results of anti-HER2 treatments in lung cancers with HER2 aberrations, thus effective therapies in these patients represent an unmet medical need. By far, encouraging efforts towards novel treatment strategies have been made to improve the clinical outcomes of these patients. In this review, we describe the biological and clinicopathological characteristics of HER2 alterations and systematically sum up recent studies on emerging therapies for this subset of patients.

Specific HER2 Exon 20 Gly776 Deletion-Insertions in Non-Small Cell Lung Cancer: Structural Analysis and Sensitivity to HER2-Targeted Tyrosine Kinase Inhibitors

Background:HER2 exon 20 insertions remain a subset heterogeneous alterations in lung cancer, with currently unmet need for precision targeted therapy. G776delinsVC, a typical HER2 exon 20 deletion-insertion at codon Gly776, was reported to respond discrepantly to afatinib compared with the predominant insertion A775_G776insYVMA (YVMA). However, it lacks structural evidence to illustrate the possible mechanism and predict the binding activities of its similar variants over YVMA insertion to HER2-targered tyrosine kinase inhibitors (TKIs).

Methods: Real-world cohort study was performed to investigate clinical outcomes with HER2-targeted TKI afatinib and pyrotinib, and structural analysis for exon 20 Gly776 deletion-insertions G776delinsVC, G776delinsLC and G776delinsVV, and YVMA by molecular dynamics simulation and cellular kinase inhibition assay were provided for full exploration.

Results: Afatinib revealed low objective response rate (ORR) of 0–9.5% and short median progression-free survival (mPFS) of 2.8–3.2 months for YVMA, but with higher ORR of 20–28.6% and longer mPFS of 4.3–7.1 months for G776delinsVC. Pyrotinib presented significantly improved PFS benefit than afatinib for G776delinsVC and YVMA as first-line (median, 6.8 vs. 3.4 months, p = 0.010) or second-line therapy (median, 5.8 vs. 2.8 months, p < 0.001). No significant difference was observed on drug binding pocket and TKI binding activity between G776delinsVC, G776delinsLC and G776delinsVV, and both afatinib and pyrotinib showed favorable binding activity. YVMA insertion significantly affected the loop region with altering HER2 protein secondary structure and forming steric hindrance to binding of afatinib. Pyrotinib showed the best selectivity to HER2, with more favorable activity to YVMA than afatinib indicated by cellular inhibition assay.

Conclusion: Both afatinib and pyrotinib showed favorable activity for NSCLC patients with HER2 exon 20 Gly776 deletion-insertions. Pyrotinib revealed more potent activity to A775_G776insYVMA insertion than afatinib due to the steric binding hindrance induced by YVMA.

Discovery of SPH5030, a Selective, Potent, and Irreversible Tyrosine Kinase Inhibitor for HER2-Amplified and HER2-Mutant Cancer Treatment

Small-molecule irreversible tyrosine kinase inhibitors as high potent agents have led to improvements in disease-free and overall survival in patients with HER2-amplified cancer. The approved irreversible HER2 inhibitors, neratinib and pyrotinib, both lack HER2 selectivity, leading to off-target adverse events in patients. The development of HER2 mutation during treatment also hampers the progress of the treatment. We used a molecular hybridization strategy for structural optimizations, in conjunction with in vitro and in vivo drug-like property screening, to obtain a clinical candidate SPH5030. Overall, SPH5030 showed excellent activities against four frequent kinds of HER2 mutants and high relative HER2 selectivity compared with neratinib and pyrotinib, good pharmacokinetic characteristics with desirable bioavailabilities, and significant in vivo antitumor efficacy in xenograft mouse models, especially in a HER2 mutation A775_G776insYVMA xenograft mouse model with its potency much higher than those of neratinib and pyrotinib.

[Targeted Therapy and Mechanism of Drug Resistance in Non-small Cell Lung Cancer with Epidermal Growth Factor Receptor Gene Mutation]

Lung cancer is the sixth leading cause of death worldwide and one of the leading cause of death from malignant tumors. Non-small cell lung cancer (NSCLC) is the most common type of lung cancer. Epidermal growth factor receptor (EGFR) gene mutation is a common mutation in NSCLC. For advanced NSCLC patients with EGFR mutations, EGFR-tyrosine kinase inhibitors (EGFR-TKIs), such as Gefitinib, Afatinib, Oxitinib and other targeted therapies have become the first-line treatment recommended by many guidelines, but many patients develop acquired drug resistance after about 1 year of medication. Patients with drug resistance will have earlier disease progression than patients without drug resistance, which has an important impact on the prognosis of patients. At present, the main treatment for patients with acquired resistance is new target inhibition for resistant mutation. For example, if patients with T790M mutation are resistant to the first or second generation drugs such as Gefitinb and Afatinib, they can be treated with the third generation drugs (Osimertinib or Almonertinib), which can delay the progression of the disease. Therefore, the study of drug resistance mechanism and treatment of drug resistance patients are essential. This paper mainly reviews targeted therapy and drug resistance mechanism of EGFR-mutant NSCLC patients, in order to provide reference for clinical application of EGFR-TKIs.
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Poziotinib for Patients With HER2 Exon 20 Mutant Non-Small-Cell Lung Cancer: Results From a Phase II Trial

PURPOSE

Targeted therapies against non-small-cell lung cancer (NSCLC) harboring HER2 mutations remain an unmet need. In this study, we assessed the efficacy and safety of poziotinib in patients with HER2 exon 20 mutant advanced NSCLC in a single-arm, open-label, phase II study.

PATIENTS AND METHODS

Patients with advanced HER2 exon 20 mutant NSCLC were enrolled to receive poziotinib at a dose of 16 mg/d for 28-day cycles. The primary end point was objective response rate per RECIST version 1.1. Confirmatory scans were performed at least 28 days from initial radiologic response.

RESULTS

Thirty patients received poziotinib treatment. At baseline, 90% of patients received prior platinum-based chemotherapy and 53% had two lines or more prior systemic therapies. As of data cutoff on March 1, 2021, the confirmed objective response rate was 27% (95% CI, 12 to 46). Responses were observed across HER2 exon 20 mutation subtypes. The median duration of response was 5.0 months (95% CI, 4.0 to not estimable). The median progression-free survival was 5.5 months (95% CI, 4.0 to 7.0). The median overall survival was 15 months (95% CI, 9.0 to not estimable). The most common grade 3 treatment-related adverse events were skin rash (47%) and diarrhea (20%). There was one possible treatment-related death because of pneumonitis.

CONCLUSION

Poziotinib showed promising antitumor activity in patients with HER2 exon 20 mutant NSCLC including patients who had previously received platinum-based chemotherapy.

Poziotinib in Non-Small-Cell Lung Cancer Harboring HER2 Exon 20 Insertion Mutations After Prior Therapies: ZENITH20-2 Trial

PURPOSE

Insertion mutations in Erb-b2 receptor tyrosine kinase 2 gene (ERBB2 or HER2) exon 20 occur in 2%-5% of non-small-cell lung cancers (NSCLCs) and function as an oncogenic driver. Poziotinib, a tyrosine kinase inhibitor, was evaluated in previously treated patients with NSCLC with HER2 exon 20 insertions.

METHODS

ZENITH20, a multicenter, multicohort, open-label phase II study, evaluated poziotinib in patients with advanced or metastatic NSCLC. In cohort 2, patients received poziotinib (16 mg) once daily. The primary end point was objective response rate evaluated by independent review committee (RECIST v1.1); secondary outcome measures were disease control rate, duration of response, progression-free survival, and safety and tolerability. Quality of life was assessed.

RESULTS

Between October 2017 and March 2021, 90 patients with a median of two prior lines of therapy (range, 1-6) were treated. With a median follow-up of 9.0 months, objective response rate was 27.8% (95% CI, 18.9 to 38.2); 25 of 90 patients achieved a partial response. Disease control rate was 70.0% (95% CI, 59.4 to 79.2). Most patients (74%) had tumor reduction (median reduction 22%). Median progression-free survival was 5.5 months (95% CI, 3.9 to 5.8); median duration of response was 5.1 months (95% CI, 4.2 to 5.5). Clinical benefit was seen regardless of lines and types of prior therapy, presence of central nervous system metastasis, and types of HER2 mutations. Grade 3 or higher treatment-related adverse events included rash (48.9%), diarrhea (25.6%), and stomatitis (24.4%). Most patients had poziotinib dose reductions (76.7%), with median relative dose intensity of 71.5%. Permanent treatment discontinuation because of treatment-related adverse events occurred in 13.3% of patients.

CONCLUSION

Poziotinib demonstrates antitumor activity in previously treated patients with HER2 exon 20 insertion NSCLC.

Consensus for HER2 alterations testing in non-small-cell lung cancer

Human epidermal growth factor receptor 2 (HER2) is a transmembrane glycoprotein receptor with intracellular tyrosine kinase activity. Its alterations, including mutation, amplification and overexpression, could result in oncogenic potential and have been detected in many cancers such as non-small-cell lung cancer (NSCLC). Such alterations are, in general, considered markers of poor prognosis. Anti-HER2 antibody-drug conjugates, e.g. trastuzumab deruxtecan (T-DXd, DS-8201) and disitamab vedotin (RC48), were recently approved for HER2-positive breast and gastric cancers. Meanwhile, several HER2-targeted drugs, such as T-DXd, neratinib, afatinib, poziotinib and pyrotinib, have been evaluated in patients with advanced NSCLC, with several of them demonstrating clinical benefit. Therefore, identifying HER2 alterations is pivotal for NSCLC patients to benefit from these targeted therapies. Recent guidelines on HER2 testing were developed for breast and gastric cancer, however, and have not been fully established for NSCLC. The expert group here reached a consensus on HER2 alteration testing in NSCLC with the focus on clinicopathologic characteristics, therapies, detection methods and diagnostic criteria for HER2-altered NSCLC patients. We hope this consensus could improve the clinical management of NSCLC patients with HER2 alterations.

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Human epidermal growth factor receptor 2 (HER2) alterations lead to poor prognosis in non-small-cell lung cancer (NSCLC).

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Identifying HER2 alterations is pivotal to guide the anti-HER2-targeted therapies in NSCLC.

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The requirements for HER2 mutation, amplification or expression testing are distinct in NSCLC.

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This consensus fills the gap in the criteria for HER2 alteration testing in NSCLC.

Efficacy and safety of pyrotinib in advanced lung adenocarcinoma with HER2 mutations: a multicenter, single-arm, phase II trial

BACKGROUND

There is currently a lack of effective treatments for non-small cell lung cancer (NSCLC) patients harboring HER2 mutations. We examined the efficacy and safety of, and potential resistance mechanism to, pyrotinib, a pan-HER inhibitor, in advanced NSCLC carrying HER2 mutations.

METHODS

In this multicenter, single-arm, phase II trial, stage IIIB-IV NSCLC patients harboring HER2 mutations, as determined using next-generation sequencing, were enrolled and treated with pyrotinib at a dose of 400 mg/day. The primary endpoint was 6-month progression-free survival (PFS) rate, and secondary endpoints were objective response rate (ORR), PFS, overall survival (OS), disease control rate (DCR), and safety. The impact of different HER2 mutation types on sensitivity to pyrotinib and the potential of utilizing mutational profile derived from circulating tumor DNA (ctDNA) to predict disease progression were also explored.

RESULTS

Seventy-eight patients were enrolled for efficacy and safety analysis. The 6-month PFS rate was 49.5% (95% confidence interval [CI], 39.2-60.8). Pyrotinib produced an ORR of 19.2% (95% CI, 11.2-30.0), with median PFS of 5.6 months (95% CI, 2.8-8.4), and median OS of 10.5 months (95% CI, 8.7-12.3). The median duration of response was 9.9 months (95% CI, 6.2-13.6). All treatment-related adverse events (TRAEs) were grade 1-3 (all, 91.0%; grade 3, 20.5%), and the most common TRAE was diarrhea (all, 85.9%; grade 3, 16.7%). Patients with exon 20 and non-exon 20 HER2 mutations had ORRs of 17.7% and 25.0%, respectively. Brain metastases at baseline and prior exposure to afatinib were not associated with ORR, PFS, or OS. Loss of HER2 mutations and appearance of amplification in HER2 and EGFR were detected upon disease progression.

CONCLUSIONS

Pyrotinib exhibited promising efficacy and acceptable safety in NSCLC patients carrying exon 20 and non-exon 20 HER2 mutations and is worth further investigation.

TRIAL REGISTRATION

Chinese Clinical Trial Registry Identifier: ChiCTR1800020262.

Patient-derived organoids as a model for tumor research

Cancer represents a leading cause of death, despite the rapid progress of cancer research, leading to urgent need for accurate preclinical model to further study of tumor mechanism and accelerate translational applications. Cancer cell lines cannot fully recapitulate tumors of different patients due to the lack of tumor complexity and specification, while the high technical difficulty, long time, and substantial cost of patient-derived xenograft model makes it unable to be used extensively for all types of tumors and large-scale drug screening. Patient-derived organoids can be established rapidly with a high success rate from many tumors, and precisely replicate the key histopathological, genetic, and phenotypic features, as well as therapeutic response of patient tumor. Therefore, they are extensively used in cancer basic research, biobanking, disease modeling and precision medicine. The combinations of cancer organoids with other advanced technologies, such as 3D bio-printing, organ-on-a-chip, and CRISPR-Cas9, contributes to the more complete replication of complex tumor microenvironment and tumorigenesis. In this review, we discuss the various methods of the establishment and the application of patient-derived organoids in diverse tumors as well as the limitations and future prospects of these models. Further advances of tumor organoids are expected to bridge the huge gap between bench and bedside and provide the unprecedented opportunities to advance cancer research.

EGFR and HER2 exon 20 insertions in solid tumours: from biology to treatment

Protein tyrosine kinases of the human epidermal growth factor receptor family, including EGFR and HER2, have emerged as important therapeutic targets in non-small-cell lung, breast and gastroesophageal cancers, and are of relevance for the treatment of various other malignancies (particularly colorectal cancer). Classic activating EGFR exon 19 deletions and exon 21 mutations, and HER2 amplification and/or overexpression, are predictive of response to matched molecularly targeted therapies, translating into favourable objective response rates and survival outcomes. By comparison, cancers with insertion mutations in exon 20 of either EGFR or HER2 are considerably less sensitive to the currently available tyrosine kinase inhibitors and antibodies targeting these receptors. These exon 20 insertions are structurally distinct from other EGFR and HER2 mutations, providing an explanation for this lack of sensitivity. In this Review, we first discuss the prevalence and pan-cancer distribution of EGFR and HER2 exon 20 insertions, their biology and detection, and associated responses to current molecularly targeted therapies and immunotherapies. We then focus on novel approaches that are being developed to more effectively target tumours driven by these non-classic EGFR and HER2 alterations.

Organoids in Lung Cancer Management

Lung cancer is a complex milieu of genomically altered cancer cells, a diverse collection of differentiated cells and nonneoplastic stroma. Lung cancer organoids is a three-dimensional structure grown from patient cancer tissue that could mimic in vivo complex behavior and cellular architecture of the cancer. Furthermore, the genomic alterations of the primary lung tumor is captured ex vivo. Lung cancer organoids have become an important preclinical model for oncology studies in recent years. It could be used to model the development of lung cancer, investigate the process of tumorigenesis, and also study the signaling pathways. The organoids could also be a platform to perform drug screening and biomarker validation of lung cancer, providing a promising prediction of patient-specific drug response. In this review, we described how lung cancer organoids have opened new avenues for translating basic cancer research into clinical therapy and discussed the latest and future developments in organoid technology, which could be further applied in lung cancer organoids research.