Poziotinib for Patients With HER2 Exon 20 Mutant Non-Small-Cell Lung Cancer: Results From a Phase II Trial

Zongertinib (BI 1810631), an Irreversible HER2 TKI, Spares EGFR Signaling and Improves Therapeutic Response in Preclinical Models and Patients with HER2-Driven Cancers

Mutations in ERBB2 (encoding HER2) occur in 2% to 4% of non-small cell lung cancer (NSCLC) and confer poor prognosis. ERBB-targeting tyrosine kinase inhibitors, approved for treating other HER2-dependent cancers, are ineffective in HER2-mutant NSCLC due to dose-limiting toxicities or suboptimal potency. We report the discovery of zongertinib (BI 1810631), a covalent HER2 inhibitor. Zongertinib potently and selectively blocks HER2, while sparing EGFR, and inhibits the growth of cells dependent on HER2 oncogenic driver events, including HER2-dependent human cancer cells resistant to trastuzumab deruxtecan. Zongertinib displays potent antitumor activity in HER2-dependent human NSCLC xenograft models and enhances the activities of antibody-drug conjugates and KRASG12C inhibitors without causing obvious toxicities. The preclinical efficacy of zongertinib translates in objective responses in patients with HER2-dependent tumors, including cholangiocarcinoma (SDC4-NRG1 fusion) and breast cancer (V777L HER2 mutation), thus supporting the ongoing clinical development of zongertinib. Significance: HER2-mutant NSCLC poses a challenge in the clinic due to limited options for targeted therapies. Pan-ERBB blockers are limited by wild-type EGFR-mediated toxicity. Zongertinib is a highly potent and wild-type EGFR-sparing HER2 inhibitor that is active in HER2-driven tumors in the preclinical and clinical settings.

The continually evolving landscape of novel therapies in oncogene-driven advanced non-small-cell lung cancer

Non-small-cell lung cancer (NSCLC) is a highly heterogeneous disease that is frequently associated with a host of known oncogenic alterations. Advances in molecular diagnostics and drug development have facilitated the targeting of novel alterations such that the majority of NSCLC patients have driver mutations that are now clinically actionable. The goal of this review is to gain insights into clinical research and development principles by summary, analysis, and discussion of data on agents targeting known alterations in oncogene-driven, advanced NSCLC beyond those in the epidermal growth factor receptor (EGFR) and the anaplastic lymphoma kinase (ALK). A search of published and presented literature was conducted to identify prospective trials and integrated analyses reporting outcomes for agents targeting driver gene alterations (except those in EGFR and ALK) in molecularly selected, advanced NSCLC. Clinical efficacy data were extracted from eligible reports and summarized in text and tables. Findings show that research into alteration-directed therapies in oncogene-driven, advanced NSCLC is an extremely active research field. Ongoing research focuses on the expansion of new agents targeting both previously identified targets (particularly hepatocyte growth factor receptor (MET), human epidermal growth factor receptor 2 (HER2), and Kirsten rat sarcoma viral oncogene homolog (KRAS)) as well as novel, potentially actionable targets (such as neuregulin-1 (NRG1) and phosphatidylinositol 3-kinase (PI3K)). The refinement of biomarker selection criteria and the development of more selective and potent agents are allowing for increasingly specific and effective therapies and the expansion of clinically actionable alterations. Clinical advances in this field have resulted in a large number of regulatory approvals over the last 3 years. Future developments should focus on the continued application of alteration therapy matching principles and the exploration of novel ways to target oncogene-driven NSCLC.

Human Epidermal Growth Factor Receptor 2 Alterations and Prognostic Implications in All Subtypes of Breast Cancers

PURPOSE

Alterations in human epidermal growth factor receptor 2 (HER2; ERBB2 gene) may be clinically relevant when considering HER2-targeted therapies. We have characterized the breadth of ERBB2 alterations (mutation, fusion, and copy number amplification) in breast cancer and explored the relationship between ERBB2 alterations and prognosis.

METHODS

DNA next-generation sequencing (592-gene panel and whole-exome sequencing) and RNA whole-transcriptome sequencing data from 12,153 breast samples were retrospectively reviewed for ERBB2 alterations. Clinicopathologic features were described, including breast cancer subtype, age, and biopsy site. HER2 status was determined according to ASCO guideline recommendations, including HER2-low. Overall survival (OS) data were obtained from insurance claims, and Kaplan-Meier estimates were calculated for defined patient cohorts. Statistical significance was determined using chi-square and Wilcoxon rank-sum tests.

RESULTS

Pathogenic ERBB2 mutations (ERBB2-mut) were identified in 3.2% (N = 388) of tumors overall, most common in liver metastases (113/1,972, 5.7%). ERBB2-mut was more common among breast lobular than ductal (10% v 2.1%; P < .001) and HER2-positive (HER2+)/low tumors (≥3.8% v 1.5% TNBC; P < .05). The most common variant was ERBB2-L755S (1.0% prevalence), enriched in metastatic tumors (1.2% v 0.6% in primary; P < .001). ERBB2 fusions were rare (0.3% prevalence). Coalterations associated with ERBB2-mutated tumors compared with ERBB2 wildtype (WT) included CDH1 (40.0% v 10.2%; P < .001) and ERBB3 (10.6% v 0.8%; P < .001). Of the 10,115 tumor samples with outcome data, ERBB2-mut was associated with worse OS compared with WT.

CONCLUSION

ERBB2-mut and fusions were observed in all breast cancer subtypes-more commonly in HER2+/low, metastatic, and lobular histology tumors-and associated with poorer prognosis.

AYVM to AYMM Transition on HER2 Exon 20 Insertion Induces Tyrosine Kinase Inhibitor Resistance in NSCLC

INTRODUCTION

Pyrotinib, a novel pan-HER tyrosine kinase inhibitor, has demonstrated substantial anti-tumor activity in patients with NSCLC harboring HER2 mutations. Nevertheless, the inevitable resistance to pyrotinib necessitates an in-depth understanding of the underlying mechanisms.

METHODS

Resistance-associated mutations were identified through genomic sequencing of paired baseline and post-resistance samples from 40 patients. Integrated computational and experimental approach were utilized to validate the resistance mechanisms and explore strategies for overcoming resistance in vitro and in vivo.

RESULTS

Analysis of novel mutations upon the development of resistance did not identify any predominant secondary HER2 mutations. Nevertheless, 12 secondary HER2 mutations (38.7%) occurred either as single nucleotide variations (75%) or insertions-deletions (25%), on the basis of HER2 p.Y772_P775dup mutation. Only two mutations led to HER2 autophosphorylation and IL3-independent proliferation of Ba/F3 cells from the in vitro experiments, implying that the remaining 10 secondary mutations were passenger mutations. Further in vivo and in vitro validation showed that the HER2 p.E770_A771insAYMM mutation diminished the sensitivity of murine HER2 mutant lung adenocarcinoma cell line to pyrotinib, with ineffective inhibition of HER2 and its downstream pathways. Drug screening indicated that mobocertinib and dacomitinib could effectively restrain the growth of tumors bearing the HER2 p.E770_A771insAYMM mutation.

CONCLUSIONS

Our findings unveil a new form of resistance-a secondary mutation superimposed on the original mutation-and offer insights into a potentially sequential strategy for overcoming resistance to pyrotinib.

Spotlight on the treatment of non-small cell lung cancer with rare genetic alterations and brain metastasis: Current status and future perspectives

In patients with non-small cell lung cancer (NSCLC), oncogenic variants present in <5% of cases are considered rare, the predominant of which include human epidermal growth factor receptor 2 (HER2) mutations, mesenchymal-epithelial transition (MET) alterations, c-ros oncogene 1 (ROS1) rearrangements, rearrangement during transfection (RET) fusions, v-raf mouse sarcoma virus oncogene homolog B1 (BRAF) mutations, and neurotrophic troponin receptor kinase (NTRK) fusions. Brain metastases (BMs) occur in approximately 10%-50% of patients with NSCLC harboring rare genetic variants. The recent advent of small-molecule tyrosine kinase inhibitors and macromolecular antibody-drug conjugates (ADCs) has conferred marked survival benefits to patients with NSCLC harboring rare driver alterations. Despite effective brain lesion control for most targeted agents and promising reports of intracranial remission associated with novel ADCs, BM continues to be a major therapeutic challenge. This review discusses the recent advances in the treatment of NSCLC with rare genetic variants and BM, with a particular focus on intracranial efficacy, and explores future perspectives on how best to treat these patients.

Efficacy of disitamab vedotin in non-small cell lung cancer with HER2 alterations: a multicenter, retrospective real-world study

Background

Non-small cell lung cancer (NSCLC) with human epidermal growth factor receptor 2 (HER2) alterations poses a substantial treatment challenge. Current HER2-targeted therapies offer limited efficacy. Antibody-drug conjugates (ADCs) targeting HER2 have emerged as a promising therapeutic strategy. This study aimed to evaluate the clinical response to a novel ADC drug Disitamab vedotin (RC48) in advanced NSCLC with HER2 alterations.

Methods

This study conducted a retrospective review of patients harboring HER2 alterations treated with RC48 in the real world. Clinical outcomes were evaluated in terms of objective response rate (ORR), disease control rate (DCR), and progression-free survival (PFS).

Results

Out of 22 patients, 21 (95.5%) received RC48 combination therapy, while one received RC48 monotherapy. The ORR of all patients reached 45.5%, and the DCR stood at 90.9%. The median PFS (mPFS) was 7.5 months. Among patients receiving RC48 combination therapy, the ORR was 47.7%, and the mPFS of 8.1 months. The combination of RC48 with platinum+/- bevacizumab resulted in the highest ORR of 71.4% (5 out of 7 patients), with HER2 TKI following at a 50.0% ORR (4 out of 8 patients). First-line (1L) treatment with RC48 showed an ORR of 62.5% (5 out of 8 patients), second-line (2L) treatments had a 57.1% ORR (4 out of 7 patients), and beyond second-line (>2L) treatments exhibited a 14.3% ORR (1 out of 7 patients). Patients with 1L, 2L, or >2L treatment had a mPFS of 8.1 months, 7.2 months, and 7.4 months, respectively. Patients with HER2 mutations or amplifications, and those with concurrent mutations and amplifications at baseline, showed mPFS of 8.1 months, 9.4 months, and 7.4 months, respectively. The mPFS was significantly longer in patients with HER2 amplification. The most common adverse events included hand-foot syndrome (54.5%), asthenia (50.0%), decreased white blood cell count (45.5%), and liver impairment (45.5%). Grade 3 adverse events occurred in one (4.5%) patient.

Conclusion

RC48, particularly in combination regimens, demonstrates promising efficacy in advanced NSCLC with HER2 alterations. These findings underscore the need for further research to validate RC48's application in clinical practice.

Unraveling the future: Innovative design strategies and emerging challenges in HER2-targeted tyrosine kinase inhibitors for cancer therapy

Human epidermal growth factor receptor 2 (HER2) is a transmembrane receptor-like protein with tyrosine kinase activity that plays a vital role in processes such as cell proliferation, differentiation, and angiogenesis. The degree of malignancy of different cancers, notably breast cancer, is strongly associated with HER2 amplification, overexpression, and mutation. Currently, widely used clinical HER2 tyrosine kinase inhibitors (TKIs), such as lapatinib and neratinib, have several drawbacks, including susceptibility to drug resistance caused by HER2 mutations and adverse effects from insufficient HER2 selectivity. To address these issues, it is essential to create innovative HER2 TKIs with enhanced safety, effectiveness against mutations, and high selectivity. Typically, SPH5030 has advanced to phase I clinical trials for its strong suppression of four HER2 mutations. This review discusses the latest research progress in HER2 TKIs, with a focus on the structural optimization process and structure-activity relationship analysis. In particular, this study highlights promising design strategies to address these challenges, providing insightful information and inspiration for future development in this field.

Prognostic and Predictive Roles of HER2 Status in Non-Breast and Non-Gastroesophageal Carcinomas

The oncogene ERBB2, also known as HER2 or c-ERB2, is located on chromosome 17 (q12). It encodes a tyrosine kinase receptor, the human epidermal growth factor receptor 2 (HER2), involved in neoplastic proliferation, tumor angiogenesis, and invasiveness. Over the past years, the introduction of various anti-HER2 therapies has significantly improved outcomes for patients with HER2-positive breast and gastroesophageal carcinomas. More recently, the introduction of a new antibody-drug conjugate, that is trastuzumab deruxtecan, expanded the therapeutic options to low-HER2 breast and gastroesophageal tumors. HER2 protein overexpression is investigated using immunohistochemistry, gene amplification using fluorescence in situ hybridization, and gene mutation using next-generation sequencing. This review evaluated the predictive and prognostic role of HER2 status in various types of epithelial malignant cancers beyond breast and gastroesophageal cancers. We critically analyzed the key published studies, focusing on utilized scoring systems and assays used, and analyzed clinical parameters and therapeutic approaches. Although the evidence about prognostic and predictive roles of HER2 in carcinomas other than breast and gastroesophageal has been widely increasing over the last decade, it still remains investigational, revealing a tumor site-related prognostic and predictive value of the different types of HER2 alterations. However, standardized and validated scoring system assays have not been well-established for many organs.

Prevalence and treatment of human epidermal growth factor receptor 2-altered non-small cell lung cancer: a retrospective analysis and systematic literature review

Human epidermal growth factor receptor 2 (HER2) is known for its oncogenic activities in diverse cancers, including non-small cell lung cancer (NSCLC). However, the prevalence of HER2 alterations in Malaysian NSCLC patients remains unreported. This study examined the prevalence and characteristics of HER2 mutations and amplification in a Malaysian cohort. Additionally, a systematic review was conducted to evaluate the global prevalence of HER2 alterations in NSCLC, as well as the efficacy of HER2-targeted therapies observed in clinical trials. NSCLC tumour samples received from October 2019 to December 2022 for next-generation sequencing diagnostics were included in the retrospective analysis. In this patient cohort, HER2 alteration was present in 5.8% of patients; 3.9% had HER2 mutations, 1.5% had HER2 amplifications and 0.4% were both HER2-mutated and amplified. HER2 exon 20 insertions were the most common HER2 variants, detected in 47/59 (79.7%) of HER2-mutated patients. Among cases with HER2 exon 20 insertions, the Y772_A775dup variant was found in 34 patient samples. HER2-mutated patients were significantly younger than non-HER2-mutants (61 versus 64 years old; p = 0.046) and were inclined to be female and never-smokers, albeit not statistically significant. Patients with HER2 amplification were more likely to have progressed post-tyrosine kinase inhibitor therapy (p = 0.015). The systematic review highlighted a global variation in the prevalence of HER2 alterations in NSCLC, ranging from 0.3% to 9.1% for mutations and 0.2% to 19% for amplification. Finally, phase II clinical trials involving HER2-altered NSCLC patients demonstrated promising treatment outcomes with trastuzumab deruxtecan, trastuzumab emtansine, pyrotinib, pyrotinib + apatinib and trastuzumab + pertuzumab + docetaxel. In conclusion, the prevalence of HER2 alteration among Malaysian NSCLC patients falls within the global range. A systematic review of clinical trials revealed promising treatment outcomes and Malaysian NSCLC patients with HER2 alterations are anticipated to similarly benefit from HER2-targeted therapies.

SHR-A1811 (antibody-drug conjugate) in advanced HER2-mutant non-small cell lung cancer: a multicenter, open-label, phase 1/2 study

A dose-escalation and expansion, phase 1/2 study (ClinicalTrials.gov, NCT04818333) was conducted to assess the novel antibody-drug conjugate SHR-A1811 in pretreated HER2-altered advanced non-small cell lung cancer (NSCLC). Here, we report results from the phase 1 portion. Patients who had previously failed or were intolerant to platinum-based chemotherapy were enrolled and received SHR-A1811 intravenously at doses of 3.2 to 8.0 mg/kg every 3 weeks. Dose escalation followed a Bayesian logistic regression model that included overdose control, with subsequent selection of tolerable levels for dose expansion. Overall, 63 patients were enrolled, including 43 receiving a recommended dose for expansion of 4.8 mg/kg. All patients had HER2-mutant disease. Dose-limiting toxicity occurred in one patient in the 8.0 mg/kg dose cohort. Grade ≥ 3 treatment-related adverse events occurred in 29 (46.0%) patients. One patient in the 6.4 mg/kg cohort died due to interstitial lung disease. As of April 11, 2023, the 4.8 mg/kg cohort showed an objective response rate of 41.9% (95% CI 27.0-57.9), and a disease control rate of 95.3% (95% CI 84.2-99.4). The median duration of response was 13.7 months, with 13 of 18 responses ongoing. The median progression-free survival was 8.4 months (95% CI 7.1-15.0). SHR-A1811 demonstrated favourable safety and clinically meaningful efficacy in pretreated advanced HER2-mutant NSCLC.

HER2-Mutant Advanced and/or Metastatic Non-Small-Cell Lung Cancer: A US Electronic Health Records Database Analysis of Clinical Characteristics, Treatment Practice Patterns, and Outcomes

BACKGROUND

Real-world data for advanced/metastatic non-small-cell lung cancer (NSCLC) with mutations in human epidermal growth factor 2 (HER2) are scarce. We aimed to assess treatment patterns and outcomes among patients with HER2-mutant advanced/metastatic NSCLC.

PATIENTS AND METHODS

This retrospective nationwide electronic health record study evaluated patient characteristics, treatment patterns, treatment duration, and overall survival for adults with HER2-mutant advanced/metastatic NSCLC without epidermal growth factor receptor mutation.

RESULTS

Of 55 included patients, median (quartile 1 [Q1]-quartile 3 [Q3]) age was 63.0 (58.0-72.0) years, 42 (76%) were women, and 39 (71%) were current/former smokers. In first-line therapy, 14 regimens were used for median (Q1-Q3) duration of 3.1 (2.4-6.2) months, with most patients (n = 39, 71%) receiving platinum-based chemotherapy alone or in combination with other agents. Median (95% CI) overall survival from first-line treatment initiation was 19.0 (12.2-not estimable) months, with no significant association with age, sex, or smoking status. Thirty-five (64%) patients received second-line therapy for median (Q1-Q3) duration of 3.3 (2.0-5.2) months. Fourteen second-line regimens were used; most commonly immunotherapy alone or in combination with other agents (n = 16, 46%). Sixteen (46%) patients received third-line therapy for median (Q1-Q3) duration of 1.9 (1.3-2.7) months. Nine third-line regimens were used, with 7 (44%) patients receiving HER2-directed agents.

CONCLUSION

First- and second-line treatments for HER2-mutant NSCLC varied widely and treatment duration was short. The approval of trastuzumab deruxtecan for NSCLC supports wider HER2 testing to identify eligible patients for HER2-directed therapy.

Current status and breakthroughs in treating advanced non-small cell lung cancer with EGFR exon 20 insertion mutations

Recently, targeted therapy and immunotherapy have emerged as effective treatment options for non-small cell lung cancer (NSCLC). This progress has been facilitated by the rapid development of diagnostic and therapeutic technologies and the continuous research and development of new drugs, leading to a new era in precision medicine for NSCLC. This is a breakthrough for patients with common mutations in the human epidermal growth factor receptor (EGFR) gene in NSCLC. Consequently, the use of targeted drugs has significantly improved survival. Nevertheless, certain rare genetic mutations are referred to as EGFR exon 20 insertion (ex20ins) mutations, which differ in structure from conventional EGFR gene mutations, namely, exon 19 deletion mutations (19-Del) and exon 21 point mutations. Owing to their distinct structural characteristics, patients harboring these EGFR ex20ins mutations are unresponsive to traditional tyrosine kinase inhibitor (TKI) therapy. This particular group of patients did not fall within the scope of their applicability. However, the activating A763_Y764insFQEA mutation elicits a more pronounced response than mutations in the near and far regions of the C-helix immediately following it and should, therefore, be treated differently. Currently, there is a lack of effective treatments for EGFR ex20ins mutations NSCLC. The efficacy of chemotherapy has been relatively favorable, whereas the effectiveness of immunotherapy remains ambiguous owing to inadequate clinical data. In addition, the efficacy of the first- and second-generation targeted drugs remains limited. However, third-generation and novel targeted drugs have proven to be effective. Although novel EGFR-TKIs are expected to treat EGFR ex20ins mutations in patients with NSCLC, they face many challenges. The main focus of this review is on emerging therapies that target NSCLC with EGFR ex20ins and highlight major ongoing clinical trials while also providing an overview of the associated challenges and research advancements in this area.

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.

Phase 1b trial of anti-HER2 antibody inetetamab and pan-HER inhibitor pyrotinib in HER2-positive advanced lung cancer

There remains an unmet need for targeted therapies against advanced non-small-cell lung cancer (NSCLC) with HER2 mutations. To improve the antitumor activity of single anti-HER2 agent, this prospective, single-arm clinical trial (NCT05016544) examined the safety profile and efficacy of anti-HER2 antibody inetetamab and pan-HER TKI pyrotinib in HER2-posivite advanced NSCLC patients. Enrolled patients received inetetamab every 3 weeks and pyrotinib once per day (pyrotinib, dose-escalation part, 240 mg, 320 mg; dose-expansion part, 320 mg). Primary endpoints were dose-limiting toxicity (DLT) dosage and safety. Secondary endpoints included progression-free survival (PFS), objective response rate (ORR), and disease control rate (DCR). A total of 48 patients were enrolled. During the dose-escalation period, no DLT occurred. Diarrhea was the most commonly reported treatment-related adverse event (TRAE). Grade 3 TRAEs occurred in seven patients. The median PFS (mPFS) was 5.5 months [95% confidence interval (CI): 4.4-8.6 months]. The confirmed ORR and DCR reached 25% (11/44) and 84.1% (37/44), respectively. Responses were shown in patients with distinct HER2 aberrations. In summary, inetetamab in combination with pyrotinib demonstrated acceptable safety and antitumor activity among patients with advanced HER2-mutant NSCLC.

EGFR and ERBB2 Exon 20 Insertion Mutations in Chinese Non-small Cell Lung Cancer Patients: Pathological and Molecular Characterization, and First-Line Systemic Treatment Evaluation

BACKGROUND

Data from studies looking at both EGFR and ERBB2 exon 20 insertion mutations (-20ins) in the same cohort of patients with non-small cell lung cancer (NSCLC) are limited.

OBJECTIVE

The purpose of this study was to analyze EGFR/ERBB2-20ins in all-stage NSCLC patients to reveal their histological and molecular features, and to retrospectively evaluate the results of first-line real-world systemic treatments in patients with advanced-stage disease.

PATIENTS AND METHODS

We collected 13,920 formalin-fixed paraffin-embedded NSCLC specimens. Clinicopathological features were recorded and DNA-based next-generation sequencing was performed. First-line systemic treatment data were obtained via chart review.

RESULTS

In total, 414 (2.97%) EGFR-20ins cases and 666 (4.78%) ERBB2-20ins cases were identified. Both were more common in women, non-smokers, and patients with adenocarcinoma. The incidence of EGFR/ERBB2-20ins in adenocarcinoma is inversely proportional to the degree of invasion; 77 and 26 variants were detected in EGFR-20ins and ERBB2-20ins cases, respectively. The most common concurrently mutated genes were TP53 and RB1. In invasive adenocarcinoma, lepidic components were more common in EGFR/ERBB2-20ins-alone cases than in those with other concurrent mutated genes. In EGFR-/ERBB2-20ins patients, there was no significant difference in progression-free survival (PFS) or treatment response to first-line systemic treatments in this study. There was no significant difference in PFS or treatment response among patients with different EGFR/ERBB2-20ins variants and those with or without concurrent mutated genes.

CONCLUSIONS

EGFR/ERBB2-20ins is more common in early lung adenocarcinoma. EGFR-20ins had more variants. In both cohorts, the results for first-line systemic treatments showed no significant difference.

Overcoming brain-derived therapeutic resistance in HER2+ breast cancer brain metastasis

Brain metastasis of HER2+ breast cancer occurs in about 50% of all women with metastatic HER2+ breast cancer and confers poor prognosis for patients. Despite effective HER2-targeted treatments of peripheral HER2+ breast cancer with Trastuzumab +/-HER2 inhibitors, limited brain permeability renders these treatments inefficient for HER2+ breast cancer brain metastasis (BCBM). The scarcity of suitable patient-derived in-vivo models for HER2+ BCBM has compromised the study of molecular mechanisms that promote growth and therapeutic resistance in brain metastasis. We have generated and characterized new HER2+ BCBM cells (BCBM94) isolated from a patient HER2+ brain metastasis. Repeated hematogenic xenografting of BCBM94 consistently generated BCBM in mice. The clinically used receptor tyrosine kinase inhibitor (RTKi) Lapatinib blocked phosphorylation of all ErbB1-4 receptors and induced the intrinsic apoptosis pathway in BCBM94. Neuregulin-1 (NRG1), a ligand for ErbB3 and ErbB4 that is abundantly expressed in the brain, was able to rescue Lapatinib-induced apoptosis and clonogenic ability in BCBM94 and in HER2+ BT474. ErbB3 was essential to mediate the NRG1-induced survival pathway that involved PI3K-AKT signalling and the phosphorylation of BAD at serine 136 to prevent apoptosis. High throughput RTKi screening identified the brain penetrable Poziotinib as highly potent compound to reduce cell viability in HER2+ BCBM in the presence of NRG1. Successful in-vivo ablation of BCBM94- and BT474-derived HER2+ brain tumors was achieved upon two weeks of treatment with Poziotinib. MRI revealed BCBM remission upon poziotinib, but not with Lapatinib treatment. In conclusion, we have established a new patient-derived HER2+ BCBM in-vivo model and identified Poziotinib as highly efficacious RTKi with excellent brain penetrability that abrogated HER2+ BCBM brain tumors in our mouse models.

HER2-targeted therapies in cancer: a systematic review

Abnormal alterations in human epidermal growth factor receptor 2 (HER2, neu, and erbB2) are associated with the development of many tumors. It is currently a crucial treatment for multiple cancers. Advanced in molecular biology and further exploration of the HER2-mediated pathway have promoted the development of medicine design and combination drug regimens. An increasing number of HER2-targeted drugs including specific monoclonal antibodies, tyrosine kinase inhibitors (TKIs), and antibody-drug conjugates (ADCs) have been approved by the U.S. Food and Drug Administration. The emergence of ADCs, has significantly transformed the treatment landscape for various tumors, such as breast, gastric, and bladder cancer. Classic monoclonal antibodies and novel TKIs have not only demonstrated remarkable efficacy, but also expanded their indications, with ADCs in particular exhibiting profound clinical applications. Moreover the concept of low HER2 expression signifies a breakthrough in HER2-targeted therapy, indicating that an increasing number of tumors and patients will benefit from this approach. This article, provides a comprehensive review of the underlying mechanism of action, representative drugs, corresponding clinical trials, recent advancements, and future research directions pertaining to HER2-targeted therapy.

Is Immunotherapy Beneficial in Patients with Oncogene-Addicted Non-Small Cell Lung Cancers? A Narrative Review

Over the past 20 years, there has been a paradigm shift in the care of patients with non-small cell lung cancer (NSCLC), who now have a range of systemic treatment options including targeted therapy, chemotherapy, immunotherapy (ICI), and antibody-drug conjugates (ADCs). A proportion of these cancers have single identifiable alterations in oncogenes that drive their proliferation and cancer progression, known as "oncogene-addiction". These "driver alterations" are identified in approximately two thirds of patients with lung adenocarcinomas, via next generation sequencing or other orthogonal tests. It was noted in the early clinical development of ICIs that patients with oncogene-addicted NSCLC may have differential responses to ICI. The toxicity signal for patients with oncogene-addicted NSCLC when treated with ICIs also seemed to differ depending on the alteration present and the specific targeted agent used. Developing a greater understanding of the underlying reasons for these clinical observations has become an important area of research in NSCLC. In this review, we analyze the efficacy and safety of ICI according to specific mutations, and consider possible future directions to mitigate safety concerns and improve the outcomes for patients with oncogene-addicted NSCLC.

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.

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 and safety of a pyrotinib-based regimen in non-small cell lung cancer patients harboring HER2 alterations: A real-world retrospective study

BACKGROUND

Pyrotinib, a novel irreversible pan-HER tyrosine kinase inhibitor, has been approved for the treatment of HER2-positive metastatic breast cancer in China. The aim of this study was to evaluate the efficacy and safety of pyrotinib in advanced nonsmall cell lung cancer (NSCLC) patients with HER2 alterations in real-world practice.

MATERIALS AND METHODS

A retrospective analysis of advanced NSCLC with HER2 mutations or amplifications who received pyrotinib-based treatment at the Qilu Hospital in Shandong University was performed. The primary end points were objective response rate and safety. The secondary end points were progression-free survival, disease control rate, and overall survival.

RESULTS

Twenty three eligible patients from a single center were enrolled between June 2019 and March 2023; among them, 21 had HER2 mutation and two harbored HER2 amplification. Evaluation of the efficacy in 21 patients revealed an objective response rate of 28.6% (6/21; 95% confidence interval [CI]: 7.5%-49.6%) and disease control rate of 85.7% (18/21). The median progression-free survival and overall survival were 7.7 months (95% CI: 6.07-9.33) and 20.8 months (95% CI: 8.42-33.18), respectively. The most common adverse events (AEs) included diarrhea (n = 14, 60.9%), nausea (n = 5, 21.7%), and liver dysfunction (n = 5, 21.7%). Seven patients (7/23, 30.4%) had grade 3-4 AE; no grade 5 AE was observed. Furthermore, one patient (1/23, 4.3%) experienced dose withdrawal and two (2/23, 8.7%) presented with dose reduction symptoms.

CONCLUSION

Pyrotinib-based therapy showed promising antitumor activity and acceptable safety in advanced NSCLC patients with HER2 alterations.

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.

Structural Mechanism and Inhibitors Targeting EGFR Exon 20 Insertion (Ex20ins) Mutations

Epidermal growth factor receptor (EGFR) targeted therapy is one of the most important and effective strategies to combat EGFR mutant nonsmall-cell lung cancer (NSCLC). However, a substantial number of patients bearing EGFR exon 20 insertion (Ex20ins) mutations respond poorly to common EGFR targeted therapies. This clinical need remained unmet until recently, when the EGFR Ex20ins mutation inhibitor mobocertinib was approved by the FDA. Despite this progress, the structural mechanisms of EGFR Ex20ins mutation resistance and characterization of inhibitor binding modes have not been systematically summarized. Herein, we analyze the structural mechanisms for ligand binding and resistance and summarize recent developments for the reported inhibitors of EGFR Ex20ins mutations. Furthermore, this Perspective aims to provide insights for the design of the next generation of EGFR Ex20ins inhibitors.

Emerging insights into mechanisms of trastuzumab resistance in HER2-positive cancers

HER2 is an established therapeutic target in breast, gastric, and gastroesophageal junction carcinomas with HER2 overexpression or genomic alterations. The humanized monoclonal antibody trastuzumab targeting HER2 has substantially improved the clinical outcomes of HER2-positive patients, yet the inevitable intrinsic or acquired resistance to trastuzumab limits its clinical benefit, necessitating the elucidation of resistance mechanisms to develop alternate therapeutic strategies. This review presents an overview of trastuzumab resistance mechanisms involving signaling pathways, cellular metabolism, cell plasticity, and tumor microenvironment, particularly discussing the prospects of developing rational combinations to improve patient outcomes.

EGFR exon 20 insertion mutations and ERBB2 mutations in lung cancer: a narrative review on approved targeted therapies from oral kinase inhibitors to antibody-drug conjugates

Background and Objective

This review will provide an overview of EGFR and ERBB2 mutations in non-small-cell lung cancer (NSCLC) with a focus on recent clinical approvals.

Methods

We obtained data from the literature in accordance with narrative review reporting guidelines.

Key Content and Findings

EGFR mutations are present in up to 15-20% of all NSCLCs; amongst these, 10% correspond to kinase domain insertions in exon 20. Structurally similar, ERBB2 (HER2) mutations occurs in 1-4% of NSCLCs, mostly consisting of insertions or point mutations. The majority of EGFR exon 20 insertions occur within the loop following the regulatory C-helix and activate the kinase domain of EGFR without generating a therapeutic window to gefitinib, erlotinib, afatinib, dacomitinib or osimertinib. Mobocertinib represents a novel class of covalent EGFR inhibitors with a modest therapeutic window to these mutants and induces anti-tumor responses in a portion of patients [at 160 mg/day: response rate of <30% with duration of response (DoR) >17 months and progression-free survival (PFS) of >7 months] albeit with mucocutaneous and gastrointestinal toxicities. The bi-specific EGFR-MET antibody amivantamab-vmjw has modest but broad preclinical activity in EGFR-driven cancers and specifically for EGFR exon 20 insertion-mutated NSCLC has response rates <40% and PFS of <8.5 months at the cost of both infusion-related plus on-target toxicities. Both drugs were approved in 2021. The clinical development of kinase inhibitors for ERBB2-mutated NSCLC has been thwarted by mucocutaneous/gastrointestinal toxicities that preclude a pathway for drug approval, as the case of poziotinib. However, the activation of ERBB2 has allowed for repurposing of antibody-drug conjugates (ADCs) that target ERBB2 with cytotoxic payloads. The FDA approved fam-trastuzumab deruxtecan-nxki in 2022 for NSCLC based on response rate of >55%, DoR >9 months, PFS >8 months and manageable adverse events (including cytopenias, nausea and less commonly pneumonitis). Other therapies in clinical development include sunvozertinib and zipalertinib, among others. In addition, traditional cytotoxic chemotherapy has some activity in these tumors.

Conclusions

The approvals of mobocertinib, amivantamab, and trastuzumab deruxtecan represent the first examples of precision oncology for EGFR exon 20 insertion-mutated and ERBB2-mutated NSCLCs.

Molecular Pathways and Mechanisms of HER2 in Cancer Therapy

The oncogene ERBB2 encoding the receptor tyrosine-protein kinase erbB-2 (HER2) is frequently overexpressed or amplified and occasionally mutated in a variety of human cancers. The early discovery of this oncogene, its established oncogenic relevance in diverse cancers, its substantial expression on the surface of cancer cells, and its druggable catalytic activity have made it one of the most pursued targets in the history of cancer drug development. Initiatives targeting HER2 provided the early stimulus for several transformational pharmaceutical technologies, including mAbs, tyrosine kinase inhibitors, antibody-drug conjugates, and others. The seismic impact of these efforts has been felt in treatment of many cancers, including breast, gastroesophageal, lung, colorectal, and others. This impact continues to broaden with increasing indications on the horizon and a plethora of novel agents in development. However, implementation of these therapeutic strategies has been complex. The clinical translation of every one of these classes of agents has been notable for underperformance or overperformance characteristics that have informed new lines of research providing deeper insights into the mechanistic complexities and unrealized opportunities provided by this molecular target. Despite all the successes to date, the preponderance of scientific evidence indicates that the full potential of HER2 as a target for cancer therapeutics is far greater than currently realized, and numerous lines of investigation are ongoing to deepen and broaden the scope of impact of HER2 as a signaling, homing, or immunologic target. In this review, we explore the existing data and evolving paradigms surrounding this remarkable target for cancer therapy.

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).

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

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

Detailed curriculum vitae of HER2-targeted therapy

With the booming development of precision medicine, molecular targeted therapy has been widely used in clinical oncology treatment due to a smaller number of side effects and its superior accuracy compared to that of traditional strategies. Among them, human epidermal growth factor receptor 2 (HER2)-targeted therapy has attracted considerable attention and has been used in the clinical treatment of breast and gastric cancer. Despite excellent clinical effects, HER2-targeted therapy remains in its infancy due to its resulting inherent and acquired resistance. Here, a comprehensive overview of HER2 in numerous cancers is presented, including its biological role, involved signaling pathways, and the status of HER2-targeted therapy.

Personalized Treatment for Patients With Lung Cancer

BACKGROUND

Lung cancer is the most common cause of death among all types of cancer in Germany, with an annual death rate of 45 000 patients. Over the past 15 years, innovations in diagnosis and treatment have prolonged the survival of patients with non-small-cell lung cancer in all tumor stages.

METHODS

This review of the diagnosis and treatment of lung cancer is based on current national and international guidelines, and on prospective trials with the highest possible level of evidence that were retrieved by a selective search of the literature.

RESULTS

Improved outcomes in patients with non-small-cell lung cancer (85% of new diagnoses) were achieved with the aid of precise diagnostic techniques, including functional imaging and endobronchial procedures for localized disease stage. Contemporary surgical and radio-oncological technologies reduce the morbidity and expand the boundaries of local therapy. Molecular pathology, including the assessment of predictive biomarkers, is an integral part of the diagnostic evaluation of non-small-cell lung cancer in all tumor stages; it enables stratified cytotoxic/molecularly targeted treatments and immunotherapies and improves patient-reported outcomes. The percentage of long-term survivors in the metastatic stage has doubled by the introduction of immunotherapy. In contrast, there has been no major improvement in the survival of patients with small-cell lung cancer (15% of new diagnoses).

CONCLUSION

In addition to the implementation of lung cancer screening in high-risk populations, the further development and consistent implementation of personalized diagnosis and treatment in certified lung cancer centers can be expected to prolong survival and improve the patients' quality of life.

Targeted Therapy for Non–Small Cell Lung Cancer

This article provides an updated review of the management of oncogene-driven non-small cell lung cancer. The use of targeted therapies for lung cancer driven by EGFR, ALK, ROS1, RET, NTRK, HER2, BRAF, MET, and KRAS are discussed, both in the first-line setting and in the setting of acquired resistance.

Rare molecular subtypes of lung cancer

Oncogenes that occur in ≤5% of non-small-cell lung cancers have been defined as 'rare'; nonetheless, this frequency can correspond to a substantial number of patients diagnosed annually. Within rare oncogenes, less commonly identified alterations (such as HRAS, NRAS, RIT1, ARAF, RAF1 and MAP2K1 mutations, or ERBB family, LTK and RASGRF1 fusions) can share certain structural or oncogenic features with more commonly recognized alterations (such as KRAS, BRAF, MET and ERBB family mutations, or ALK, RET and ROS1 fusions). Over the past 5 years, a surge in the identification of rare-oncogene-driven lung cancers has challenged the boundaries of traditional clinical grade diagnostic assays and profiling algorithms. In tandem, the number of approved targeted therapies for patients with rare molecular subtypes of lung cancer has risen dramatically. Rational drug design has iteratively improved the quality of small-molecule therapeutic agents and introduced a wave of antibody-based therapeutics, expanding the list of actionable de novo and resistance alterations in lung cancer. Getting additional molecularly tailored therapeutics approved for rare-oncogene-driven lung cancers in a larger range of countries will require ongoing stakeholder cooperation. Patient advocates, health-care agencies, investigators and companies with an interest in diagnostics, therapeutics and real-world evidence have already taken steps to surmount the challenges associated with research into low-frequency drivers.

Multiple post-translational modifications ensure EGFR functionality: Potential therapeutic targets to overcome its drug-resistance mutations

Epidermal growth factor receptor (EGFR) mutation is the most common driver mutation in non-small cell lung cancer (NSCLC). The first-line therapy for advanced NSCLC patients with EGFR-sensitive mutation is the EGFR tyrosine kinase inhibitor (EGFR-TKI). However, most NSCLC patients with EGFR mutation will develop resistant mutations in EGFR-TKI therapy. With further studies, resistance mechanisms represented by EGFR-T790M mutations have revealed the impact of EGFR mutations in situ on EGFR-TKIs sensitivity. The third-generation EGFR-TKIs inhibit both EGFR-sensitive mutations and T790M mutations. The emergence of novel mutations such as EGFR-C797S and EGFR-L718Q may decrease efficacy. Searching for new targets to overcome EGFR-TKI resistance becomes a key challenge. Therefore, an in-depth understanding of the regulatory mechanisms of EGFR is essential to find novel targets to overcome drug-resistant mutations in EGFR-TKIs. EGFR, as a receptor-type tyrosine kinase, undergoes homo/heterodimerization and autophosphorylation upon binding to ligands, which activates multiple downstream signaling pathways. Interestingly, there is growing evidence that the kinase activity of EGFR is affected not only by phosphorylation but also by various post-translational modifications (PTMs, such as S-palmitoylation, S-nitrosylation, Methylation, etc.). In this review, we systematically review the effects of different protein PTMs on EGFR kinase activity and its functionality and suggest that influencing EGFR kinase activity by modulating multiple EGFR sites are potential targets to overcome EGFR-TKIs resistance mutations.

Targeting HER2 alterations in non-small cell lung cancer: Therapeutic breakthrough and challenges

In non-small cell lung cancer (NSCLC) with human epidermal growth factor receptor 2 (HER2) alterations, chemotherapy remains the standard treatment over a decade, due to the minor efficacy of traditional pan-HER tyrosine kinase inhibitors (TKIs) and HER2-targeted monoclonal antibodies. In recent years, novel selective HER2 TKIs have been developed for pretreated HER2-mutant patients. In particular, pyrotinib has shown moderate efficacy as well as a manageable safety profile, and it is now being further evaluated as monotherapy or combined with other existing therapies; by contrast, while poziotinib has demonstrated promising preliminary results, the high rates of toxicity has hampered subsequent studies. Most notably, trastuzumab deruxtecan (T-DXd, DS-8201) has led to a significant breakthrough, with the most encouraging efficacy data (response rate of 55 %, median progression-free survival of 8.2 months and median overall survival of 17.8 months) among all the anti-HER2 agents. This is certainly remarkable progress, and T-DXd is undoubtedly the key drug for the treatment of this disease. Future developments regarding T-DXd are favourable, including shifting from monotherapy to combination strategies, improving structural design to optimise antitumour activity and minimise toxicity, identifying the potential resistance mechanisms and developing therapeutic strategies to overcome them. Several other challenges need to be addressed, such as the intracranial activity of anti-HER2 agents and the optimal sequencing of therapies. Here, we summarise recent therapeutic advances in targeting HER2 alterations in NSCLC and highlight the future perspectives of these patient populations.

A Phase I, Open-Label, Dose Confirmation, Escalation, and Expansion Trial of BI 1810631 as Monotherapy in Patients With Advanced or Metastatic Solid Tumors With HER2 Aberrations

BACKGROUND

BI 1810631 is a human HER2-selective tyrosine kinase inhibitor that covalently binds to both wild-type and mutated HER2 receptors, including exon 20 insertion mutations, whilst sparing EGFR signaling. This phase Ia/Ib, open-label, non-randomized study will determine the safety, maximum tolerated dose (MTD), pharmacokinetics (PK), pharmacodynamics, and preliminary efficacy of BI 1810631 in patients with HER2 aberration-positive solid tumors (NCT04886804).

PATIENTS AND METHODS

In phase Ia, patients with histologically/cytologically confirmed HER2 aberration-positive advanced/metastatic solid tumors will receive BI 1810631 orally twice daily (BID) or once daily (QD) at escalating doses. Starting dose level is 15 mg BID; QD schedule will begin after one dose level above estimated therapeutic dose of BI 1810631 is determined safe by the Dose Escalation Committee. Dose escalation will continue until MTD/recommended phase II dose and preferred phase Ib schedule for each schedule is determined. In phase Ib, patients with HER2 tyrosine kinase domain (TKD) mutation-positive non-small cell lung cancer (NSCLC) who have previously received ≥1 line of systemic therapy will be enrolled initially, with possible inclusion of additional NSCLC cohorts in the future, including untreated patients. The primary endpoints will be MTD based on number of dose-limiting toxicities (DLTs)/number of patients with DLTs (phase Ia) and objective response (phase Ib). Secondary endpoints include PK parameters (phase Ia/Ib); duration of response, disease control, duration of disease control, and progression-free survival (phase Ib).

CONCLUSIONS

BI 1810631 could be an effective and tolerable EGFR-sparing oral treatment for patients with HER2 mutation-positive NSCLC, including exon 20 insertion mutations.

CLINICALTRIALS

GOV IDENTIFIER

NCT04886804.

Evolving Treatment Landscape of HER2-mutant Non-Small Cell Lung Cancer: Trastuzumab Deruxtecan and Beyond

Successful targeting of HER2-activating mutations in DESTINY-Lung02 phase II study has led to the approval of the antibody-drug conjugate (ADC) trastuzumab deruxtecan (T-DXd) as second-line treatment in patients with non-small cell lung cancer (NSCLC). Despite the impressive results, several matters need to be addressed, including the clinical activity of T-DXd in patients with disease in the central nervous system as well as the role of T-DXd in the context of HER2 overexpression. Additionally, data regarding novel agents used to target HER2 continue to accumulate. This review highlights the challenges and unanswered questions that have emerged after the approval of T-DXd in patients with HER2-mutant NSCLC.

Targeting HER2-positive breast cancer: advances and future directions

The long-sought discovery of HER2 as an actionable and highly sensitive therapeutic target was a major breakthrough for the treatment of highly aggressive HER2-positive breast cancer, leading to approval of the first HER2-targeted drug - the monoclonal antibody trastuzumab - almost 25 years ago. Since then, progress has been swift and the impressive clinical activity across multiple trials with monoclonal antibodies, tyrosine kinase inhibitors and antibody-drug conjugates that target HER2 has spawned extensive efforts to develop newer platforms and more targeted therapies. This Review discusses the current standards of care for HER2-positive breast cancer, mechanisms of resistance to HER2-targeted therapy and new therapeutic approaches and agents, including strategies to harness the immune system.

Molecular Epidemiology and Treatment Patterns of Patients With EGFR Exon 20-Mutant NSCLC in the Precision Oncology Era: The European EXOTIC Registry

Introduction

Real-world evidence regarding molecular epidemiology and management patterns of patients with EGFR exon-20 mutated, advanced NSCLC outside the context of clinical trials is lacking.

Methods

We created a European registry for patients with advanced EGFR exon 20-mutant NSCLC diagnosed from January 2019 to December 2021. Patients enrolled in clinical trials were excluded. Clinicopathologic and molecular epidemiology data were collected, and treatment patterns were recorded. Clinical end points according to treatment assignment were assessed using Kaplan-Meier curves and Cox regression models.

Results

Data on 175 patients from 33 centers across nine countries were included in the final analysis. Median age was 64.0 (range: 29.7-87.8) years. Main features included female sex (56.3%), never or past smokers (76.0%), adenocarcinoma (95.4%), and tropism for bone (47.4%) and brain (32.0%) metastases. Mean programmed death-ligand 1 tumor proportional score was 15.8% (range: 0%-95%) and mean tumor mutational burden was 7.06 (range: 0-18.8) mutations per megabase. Exon 20 was detected in the tissue (90.7%), plasma (8.7%), or both (0.6%), using mostly targeted next-generation sequencing (64.0%) or polymerase chain reaction (26.0%). Mutations were mainly insertions (59.3%), followed by duplications (28.1%), deletions-insertions (7.7%), and the T790M (4.5%). Insertions and duplications were located mainly in the near loop (codons 767-771, 83.1%) and the far loop (codons 771-775, 13%) and only in 3.9% within the C helix (codons 761-766). Main co-alterations included mutations in TP53 (61.8%) and MET amplifications (9.4%). Treatment on mutation identification included chemotherapy (CT) (33.8%), CT-immunotherapy (IO) (18.2%), osimertinib (22.1%), poziotinib (9.1%), mobocertinib (6.5%), mono-IO (3.9%), and amivantamab (1.3%). Disease control rates were 66.2% with CT plus or minus IO, 55.8% with osimertinib, 64.8% with poziotinib, and 76.9% with mobocertinib. Corresponding median overall survival was 19.7, 15.9, 9.2, and 22.4 months, respectively. In multivariate analysis, type of treatment (new targeted agents versus CT ± IO) affected progression-free survival (p = 0.051) and overall survival (p = 0.03).

Conclusions

EXOTIC represents the largest academic real-world evidence data set on EGFR exon 20-mutant NSCLC in Europe. Indirectly compared, treatment with new exon 20-targeting agents is likely to confer survival benefit than CT plus or minus IO.

Poziotinib in non-small-cell lung cancer patients with HER2 exon 20 mutations: A pooled analysis of randomized clinical trials

BACKGROUND

Non-small-cell lung cancer (NSCLC) harboring human epidermal growth factor receptor 2 (HER2) exon 20 mutant occurs in 3% of NSCLCs. Targeted agents for this population remain an unmet need. In this analysis, we pooled-analyzed the efficacy and safety of poziotinib, a novel tyrosine kinase inhibitor, in HER2 exon 20 mutant NSCLC.

METHODS

PubMed, Embase, Web of Science, and Cochrane CENTRAL databases were systematically searched on March 9, 2022. The primary endpoints were objective response rate (ORR) and disease control rate. The secondary endpoint was treatment-related adverse events.

RESULTS

Three prospective clinical trials, involving 126 patients, were identified. The pooled ORR and disease control rate of poziotinib in HER2 exon 20 mutant NSCLC were 27% (95% CI, 19-35) and 72% (95% CI, 64-80), respectively. Patients with G778_P780dupGSP had the highest ORR (88%; 95% CI, 33-100; n = 12), followed by Y772_A775dupYVMA (20%; 95% CI, 12-30; n = 88) and G776delinsVC (19%; 95% CI, 0-50; n = 13). The most common grade 3 to 4 treatment-related adverse events were skin rash (36%), diarrhea (23%), and oral mucositis (13%).

CONCLUSION

Poziotinib demonstrates moderate antitumor activity in previously treated HER2 exon 20 mutant NSCLC patients with a manageable safety profile. In addition, different subgroup mutations show various benefits of poziotinib treatment. Large-scale and multiarm clinical trials are warranted to confirm a suitable population and therapeutic strategies.

An ultra-performance LC-MS/MS method for determination of JRF103 in human plasma: application in first-in-patient study

Background: JRF103, a novel pan-HER inhibitor, has shown potent activity against HER1, HER2, HER4 and EGFR in vitro. To support its first-in-patient trial, a sensitive and rapid method was developed and validated using ultra-performance LC-MS/MS. Materials & methods: JRF103 was extracted from plasma using protein precipitation. Extracts were subjected to ultra-performance LC-MS/MS with electrospray ionization. Results: Separation of analyte was achieved using a 1.7-μm C₁₈ column (2.1 × 50-mm internal diameter) with a gradient elution. The developed method was fully validated following the international guides. Conclusion: The developed method was sensitive, specific and suitable for measuring JRF103 concentration in patients with advanced solid tumors in the first-in-patient study of JRF103.

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.

Clinical and Genomic Features of HER2 Exon 20 Insertion Mutations and Characterization of HER2 Expression by Immunohistochemistry in East Asian Non–Small-Cell Lung Cancer

PURPOSE

HER2-altered non–small-cell lung cancer (NSCLC) represents a diverse subgroup, including mutations, amplifications, and overexpression. However, HER2 exon 20 insertion mutations are emerging as a distinct molecular subtype with expanding therapeutic options. We describe the molecular epidemiology and genomic features of HER2-altered NSCLC in an Asian tertiary cancer center.

METHODS

We identified patients with HER2-mutated NSCLC in our institutional database, collating clinicopathological features and treatment outcomes. The genomic landscape of human epidermal growth factor receptor 2 ( HER2)–mutated NSCLC was further evaluated using whole-exome sequencing (WES) data from combined local and publicly available data sets. HER2 amplification and overexpression as selection biomarkers in NSCLC were further interrogated using HER2 immunohistochemistry and correlations with WES and RNA sequencing data.

RESULTS

Among 1,252 patients with consecutive lung adenocarcinoma undergoing routine next-generation sequencing, the prevalence of HER2 mutations was 3.1%—exon 20 insertion mutations comprised 2.7%. We examined the clinicopathological features in 55 patients with HER2-mutated NSCLC comprising 40 exon 20 insertion and 15 nonexon 20 insertion mutations. The most common exon 20 insertion mutation was HER2Y772_A775dup in 30 (75%), followed by HER2G776delinsVC in five patients (13%). There were limited responses to HER2-directed therapies apart from trastuzumab-deruxtecan, and no responses were seen with immunotherapy monotherapy. Evaluating the genomics features of HER2 exon 20 insertion mutations using WES data revealed low tumor mutational burden (TMB), low incidence of cancer driver comutations, and a predominance of aging mutational signature—similar to EGFR-mutated tumors. In contrast, uncommon (or nonexon 20 insertion) HER2-mutated tumors resembled EGFR wild-type tumors with higher TMB, higher frequency of cancer driver comutations, and greater presence of smoking and APOBEC mutational signature. Finally, in evaluating HER2 immunohistochemistry in all lung adenocarcinoma, there was significant discordance comparing different scoring systems and poor correlation with HER2 RNA expression and HER2 amplification.

CONCLUSION

The incidence of HER2 mutations is 3.1% in East Asian nonsquamous NSCLC. HER2 exon 20 insertion–mutated tumors appear genomically distinct from uncommon (nonexon 20 insertion) HER2 mutations, the latter demonstrating higher TMB, co-occurring drivers, and predominant nonaging mutational signature. The therapeutic implications of the genomic and clinical features of HER2-mutated NSCLC warrant further investigation.

HER2-targeted advanced metastatic gastric/gastroesophageal junction adenocarcinoma: treatment landscape and future perspectives

Recently, the global incidence of gastric/gastroesophageal junction (G/GEJ) cancer has remained high. China is also a large country with a high gastric cancer (GC) incidence rate, where the cases of GC account for 40% of all cases worldwide. More than 90% of GEJ cancers are the adenocarcinoma pathological type. Patients with early-stage G/GEJ adenocarcinoma may have a better prognosis after surgery. In contrast, patients with advanced metastatic G/GEJ adenocarcinoma usually choose comprehensive treatment based on systemic pharmacotherapy, but the subsequent long-term survival is not optimistic. The discovery of various biomarkers, especially microsatellite instability (MSI), programmed cell death-ligand 1 (PD-L1), human epidermal growth factor receptor 2 (HER2), tumor mutational burden (TMB) and Epstein-Barr virus (EBV), has led to the identification of an increasing number of targeted populations and has greatly improved the clinical efficacy of treatments for G/GEJ adenocarcinoma. The ToGA trial added trastuzumab to standard chemotherapy, showed improved survival of patients with HER2-positive advanced G/GEJ adenocarcinoma and brought these patients into a new era of HER2-targeted therapy. Moreover, many HER2-targeted agents have been developed and studied in patients with advanced HER2-positive G/GEJ adenocarcinoma who have demonstrated excellent clinical outcomes. However, many patients experience disease progression with HER2-targeted therapy; hence, new anti-HER2 drugs keep being developed, significantly reducing HER2 resistance. This paper reviews HER2-targeted drugs for advanced metastatic G/GEJ adenocarcinoma, potential resistance mechanisms and future directions.

Real-world clinical treatment outcomes in Chinese non-small cell lung cancer with EGFR exon 20 insertion mutations

Background

EGFR exon 20 insertions (EGFR ex20ins) constitute a heterogeneous subset of EGFR-activating alterations. However, the effectiveness of standard therapy in patients with EGFR ex20ins remains poor.

Methods

In our study, we retrospectively collected next-generation sequencing (NGS) data from 7,831 Chinese NSCLC patients and analyzed the relationship between EGFR ex20ins variations and medical records.

Results

Our data showed that EGFR ex20ins account for up to 3.5% of all EGFR mutation non-small-cell lung cancer (NSCLC) patients and 1.6% of all NSCLC patients in China. Thirty-eight different variants of EGFR ex20ins were identified in 129 NSCLC patients. We observed that the patients with EGFR ex20ins may benefit from the anti-angiogenesis agents significantly (P = 0.027). In the EGFR ex20ins near-loop group, patients who received second-/third-generation EGFR-TKI therapy treatment as first-line treatment had a longer median progression-free survival (PFS) than those who initiated treatment with first-generation EGFR-TKI or chemotherapy. Patients with co-mutations of EGFR ex20ins near-loop and TP53 tended to have a shorter OS in second-/third-generation EGFR-TKI therapy (P = 0.039). Additionally, median PFS was significantly longer in patients harboring EGFR ex20ins far-loop variants who received chemotherapy as a first-line setting (P = 0.037).

Conclusions

Overall survival was significantly longer in EGFR ex20ins patients with anti-angiogenesis agents. For the choice of first-line strategy, NSCLC with EGFR ex20ins near-loop variants may benefit from second-/third-generation EGFR-TKI, while patients harboring EGFR ex20ins far-loop variants might have better outcomes from chemotherapy. TP53 could serve as a potential predictive marker in poor prognosis for EGFR ex20ins near-loop patients.

Emerging tyrosine kinase inhibitors for head and neck cancer

INTRODUCTION

Conventional regimens for head and neck squamous cell carcinoma (HNSCC) are limited in efficacy and are associated with adverse toxicities. Food and Drug Administration (FDA) approved molecular targeting agents include the HER1 (EGFR)-directed monoclonal antibody cetuximab and the immune checkpoint inhibitors nivolumab and pembrolizumab. However, clinical benefit is only seen in roughly 15-20% of HNSCC patients treated with these agents. New molecular targeting agents are needed that either act with monotherapeutic activity against HNSCC tumors or enhance the activities of current therapies, particularly immunotherapy. Small-molecule tyrosine kinase inhibitors (TKIs) represent a viable option toward this goal.

AREAS COVERED

This review provides an update on TKIs currently under investigation in HNSCC. We focus our review on data obtained and trials underway in HNSCC, including salivary gland cancers and nasopharyngeal carcinomas, but excluding thyroid cancer and esophageal cancer.

EXPERT OPINION

While some emerging TKIs have shown clinical benefit, the positive effects have, largely, been modest. The design of clinical trials of TKIs has been hampered by a lack of understanding of biomarkers that can be used to define patient populations most likely to respond. Further preclinical and translational studies to define biomarkers of TKI response will be critically important.

Novel treatment approaches for HER2 positive solid tumors (excluding breast cancer)

PURPOSE OF REVIEW

Human epidermal growth factor 2 (HER2) alterations (protein overexpression, gene amplification and mutation) play a key role in oncogenesis and are more likely correlated to poorer outcome in solid tumors. We reviewed recently published studies in the last 18 months on novel treatment approaches for HER2 positive solid tumors (excluding breast cancer).

RECENT FINDINGS

Results of clinical studies assessing anti-HER2 therapies have been recently issued.One of the most promising drugs is transtuzumab deruxtecan, an antibody-drug conjugate which demonstrated clinically meaningful activity in gastric or gastroesophageal junction cancer and colorectal cancers.Small molecules such as poziotinib, pyrotinib, neratinib, which target both epidermal growth factor receptor (EGFR) and HER2 also showed promising activity, especially in heavily pretreated ERRB2-mutated non-small cell lung cancer (NSCLC) cancer patients. Yet, these findings need to be confirmed in confirmatory randomized trials with larger cohorts.Trastuzumab-based combinations with chemotherapy or immune checkpoint inhibitors are under development with promising results, but not in all HER2 tumors. Emerging adverse events with anti-HER2 are interstitial pneumopathy and diarrhea.

SUMMARY

Tyrosine kinase inhibitors, antibody drug conjugate in monotherapy and combinations are emerging strategies in many HER2-positive cancers; HER2 therapies are now part of standard of care of HER2-amplified gastric or gastroesophageal junction cancer. Data are pending on several unmet medical needs.

Pyrotinib combined with apatinib for targeting metastatic non-small cell lung cancer with HER2 alterations: a prospective, open-label, single-arm phase 2 study (PATHER2)

BACKGROUND

Although targeted agents have been gradually applied in the treatment of HER2-mutated non-small cell lung cancer (NSCLC) in recent years, patients' therapeutic demands are far from being met. PATHER2 was the first phase 2 trial to explore the efficacy and safety of the HER2-targeted tyrosine kinase inhibitor (TKI) pyrotinib plus the antiangiogenic agent apatinib in previously treated HER2-altered metastatic NSCLC patients.

METHODS

HER2-mutated or HER2-amplified metastatic NSCLC patients who had failed at least first-line chemotherapy or HER2-targeted TKIs received oral pyrotinib 400 mg plus apatinib 250 mg once daily until disease progression, intolerable toxicity, or death. The primary endpoint was the investigator-assessed objective response rate (ORR).

RESULTS

Between March 2019 and December 2020, 33 patients were enrolled; 13 (39.4%) presented brain metastases, and 16 (48.5%) had received at least two lines of prior chemotherapy or HER2-targeted TKIs. As of September 20, 2021, the median follow-up duration was 11.3 (range, 3.5-26.0) months. The investigator-assessed ORR was 51.5% (17/33; 95% CI, 33.5 to 69.2%), and the disease control rate was 93.9% (31/33; 95% CI, 79.8 to 99.3%). The median duration of response, progression-free survival, and overall survival were 6.0 (95% CI, 4.4 to 8.6) months, 6.9 (95% CI, 5.8 to 8.5) months, and 14.8 (95% CI, 10.4 to 23.8) months, respectively. The most frequent grade ≥ 3 treatment-related adverse events included diarrhea (3.0%) and hypertension (9.1%). No treatment-related deaths were reported.

CONCLUSIONS

Pyrotinib plus apatinib demonstrated promising antitumor activity and a manageable safety profile in HER2-mutated or HER2-amplified metastatic NSCLC patients.

TRIAL REGISTRATION

Chinese Clinical Trial Registry Identifier: ChiCTR1900021684 .

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.

Advanced non-small-cell lung cancer: how to manage EGFR and HER2 exon 20 insertion mutation-positive disease

EGFR exon 20 insertion mutations (Ex20ins) and HER2 mutations characterize an oncogene-addicted subtype of non-small-cell lung cancer (NSCLC) typically associated with a never or light smoking history, female sex, and adenocarcinoma histology. Nevertheless, Ex20ins-mutant and HER2-mutant advanced NSCLCs are still difficult to treat for various reasons. First, there is a need for sophisticated diagnostic tools (e.g. next-generation sequencing) that could allow the identification of these relatively rare molecular drivers. Second, highly active targeted drugs that might support a significant change in patients' prognosis when used as first-line therapy are required. In fact, although a few targeted drugs have so far demonstrated antitumour activity for these patients, mainly selective human epidermal receptor-tyrosine kinase inhibitors such as poziotinib and mobocertinib (for both molecular alterations), monoclonal antibodies such as amivantamab (for Ex20ins), and antibody-drug conjugates such as trastuzumab deruxtecan (for HER2 mutants), they are mostly confined for clinical use in pretreated patients. Finally, Ex20ins-targeted or HER2-targeted drugs might be difficult to access in different countries or regions worldwide. In the present review, we provide a concise but comprehensive summary of the challenges that lie ahead as we move towards personalized treatment of Ex20ins-mutant and HER2-mutant advanced NSCLC, also suggesting a treatment algorithm that could be followed for patients with these genetic aberrations.

Molecular Landscape of ERBB2 Alterations in 14,956 Solid Tumors

ERBB2 abnormalities frequently occur and serve as rationale therapeutic targets in cancer. In this study, clinical and next-generation sequencing data from 14,956 patients across more than 20 tumor types were collected. A total of 406 (2.7%) patients were identified with ERBB2 amplifications, and 303 (2.0%) patients with pathogenic somatic ERBB2 mutations. ERBB2 amplifications fell most frequently in breast (15.9%) and stomach (8.3%) cancers. Somatic ERBB2 SNVs/indels occurred most common in bladder/urinary tract (7.3%) and intestine (6.1%) cancers. The top mutated ERBB2 SNVs/indels were p.Y772_A775dup (25.5%) and p.S310F/Y (19.9%). Significantly higher rates of ERBB2 SNV/indels were found in women compared to men (2.8% vs. 1.5%, p &lt; 0.0001). CDK12 was the most common co-amplification gene with ERBB2 in cancers with a high frequency of ERBB2 amplifications. Patients with ERBB2 amplifications or mutations had higher TMB compared with patients with non-ERBB2 alterations. The study provided the landscape of ERBB2 alterations across a variety of solid tumors that may benefit from anti-HER2 agents.