Non-small-cell lung cancer with HER2 exon 20 mutation: regression with dual HER2 inhibition and anti-VEGF combination treatment

Pyrotinib plus antiangiogenic agents for HER2-altered advanced non-small cell lung cancer: A retrospective real-world study

BACKGROUND

Although some targeted therapies have been shown to be effective in treating HER2-altered non-small cell lung cancer (NSCLC), the survival demands have not yet been met due to the high cost and limited availability. This study aimed to assess the effectiveness and safety of pyrotinib plus antiangiogenic agents, including apatinib, anlotinib, and bevacizumab, in previously treated patients with HER2-altered advanced NSCLC.

METHODS

In this retrospective real-world study, patients with HER2-altered NSCLC who received pyrotinib plus antiangiogenic agents as a second- or later-line treatment between November 2015 and January 2022 were reviewed. The objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), overall survival (OS), and safety profiles of patients were analyzed.

RESULTS

A total of 107 patients were included in the analysis, of which 59 patients (55.1%) had received at least two lines of prior chemotherapy or tyrosine kinase inhibitors. Most of them (87.9%) were identified as harboring HER2 exon 20 insertions. At the data cutoff date (May 13, 2022), the ORR, DCR, median PFS, and median OS were 19.6% (21/107), 94.4% (101/107), 7.13 months (95% confidence interval [CI]: 6.26-8.01), and 19.50 months (95% CI: 12.83-26.17), respectively. There was no difference in the PFS between patients receiving apatinib or anlotinib/bevacizumab (median PFS, 7.13 vs. 6.27 months, hazard ratio [HR] = 1.49, 95% CI: 0.87-2.54, p = 0.15). The most frequent grade 3 or higher treatment-related adverse events was diarrhea (17.6%), followed by hypertension (11.0%) and nausea (3.3%). No treatment-related death occurred.

CONCLUSION

In this study, pyrotinib plus antiangiogenic agents demonstrated promising efficacy and were tolerable in HER2-altered NSCLC patients.

Cetuximab in Patients with Non-Small Cell Lung Cancer and EGFR Exon 20 Insertion Alterations

Epidermal Growth Factor Receptor (EGFR) exon 20 insertion alterations represent 4%-10% of all EGFR mutations in Non-Small Cell Lung Cancer (NSCLC) and result in resistance to standard EGFR-directed therapies. EGFR exon 20 insertions restrict the size of the kinase pocket, prohibiting the entry of approved EGFR kinase inhibitor drugs. Structural In Silico modeling also predicts that EGFR exon 20 insertion anomalies increase attractive electrostatic dimerization, hence stabilizing the activating dimer configuration. EGFR antibodies such as cetuximab that interfere with dimerization may lead to responses. We identified three non-smoking patients with NSCLC and EGFR exon 20 insertions treated with cetuximab-based therapy. All three patients demonstrated clinical benefit. A 58-year-old woman achieved prolonged stable disease lasting 9 months, while a 76-year-old woman and 38-year-old man maintained a partial response with progression-free survivals of 13 months and 32 months, respectively. In conclusion, cetuximab merits further investigation as it appears to be an additional promising therapy for overcoming EGFR exon 20 insertion-related resistance.

Phase I Study of Everolimus, Letrozole, and Trastuzumab in Patients with Hormone Receptor-positive Metastatic Breast Cancer or Other Solid Tumors

PURPOSE

Doublets of everolimus with letrozole or trastuzumab have demonstrated activity against HER2-positive breast cancer, suggesting that the triple combination can have synergistic anticancer activity.

PATIENTS AND METHODS

This first-in-human dose-escalation study (NCT02152943) enrolled patients with hormone receptor- positive, HER2-positive (defined by amplification, overexpression, or mutation) treatment-refractory advanced cancers to receive escalating doses (3+3 design) of daily oral letrozole (days 1-21), daily oral everolimus (days 1-21), and intravenous trastuzumab (day 1) every 21 days to determine dose-limiting toxicities (DLT) and MTD or recommended phase II dose (RP2D).

RESULTS

A total of 32 patients with hormone receptor-positive, HER2-positive (amplification, n = 27; overexpression, n = 1; and mutation, n = 4) advanced breast cancer (n = 26) or other cancers (n = 6) were enrolled. The most frequent grade ≥3 adverse events included hyperglycemia (n = 4), anemia (n = 3), thrombocytopenia (n = 2), and mucositis (n = 2). DLTs included grade 3 mucositis and grade 4 neutropenia, and trastuzumab given as an 8 mg/kg loading dose on day 1 of cycle 1 followed by a 6 mg/kg maintenance dose on day 1 of subsequent cycles plus 10 mg everolimus daily and 2.5 mg letrozole daily every 21 days was declared as RP2D. Five patients with breast cancer (four with HER2 amplification and one with HER2 mutation) had partial responses. HER2 amplification in circulating cell-free DNA at baseline was associated with shorter progression-free and overall survival durations (P < 0.05).

CONCLUSIONS

Everolimus, letrozole, and trastuzumab have a favorable safety profile and elicit encouraging signals of anticancer activity in patients with heavily pretreated hormone receptor- and HER2-positive advanced cancers.

New therapeutic approaches to overcoming resistant EGFR exon 20 alterations

EGFR exon 20 alterations are rare events seen mainly in non-small cell lung cancer (NSCLC). They include EGFR T790 and C797S mutations (associated with secondary resistance to classic EGFR tyrosine kinase inhibitors (TKIs)), and EGFR exon 20 in-frame insertions (associated with resistance to first- and second-generation EGFR TKIs). In silico modeling of structural changes in aberrant proteins has informed selection of compounds with potential clinical activity: poziotinib (whose smaller size permits access to the restricted kinase pocket created by EGFR and ERBB2 exon 20 insertions); cetuximab (an antibody that attenuates dimerization caused by EGFR exon 20 insertions), and TAK-788 (another EGFR/ERBB2 TKI). Other alterations, such as EGFR T790 M, are responsive to osimertinib, while the EGFR C797S alteration seen in osimertinib resistance demonstrates preclinical sensitivity to combined brigatinib and cetuximab. These observations indicate that clinical resistance can be overcome by utilizing advanced genomic interrogation coupled with computer modeling.

Emergence of ERBB2 Mutation as a Biomarker and an Actionable Target in Solid Cancers

The oncogenic role ERBB2 amplification is well established in breast and gastric cancers. This has led to the development of a well-known portfolio of monoclonal antibodies and kinase inhibitors targeting the ERBB2 kinase. More recently, activating mutations in the ERBB2 gene have been increasingly reported in multiple solid cancers and were shown to play an oncogenic role similar to that of ERBB2 amplification. Thus, ERBB2 mutations define a distinct molecular subtype of solid tumors and serve as actionable targets. However, efforts to target ERBB2 mutation has met with limited clinical success, possibly because of their low frequency, inadequate understanding of the biological activity of these mutations, and difficulty in separating the drivers from the passenger mutations. Given the current impetus to deliver molecularly targeted treatments for cancer, there is an important need to understand the therapeutic potential of ERBB2 mutations. Here we review the distribution of ERBB2 mutations in different tumor types, their potential as a novel biomarker that defines new subsets in many cancers, and current data on preclinical and clinical efforts to target these mutations. IMPLICATIONS FOR PRACTICE: A current trend in oncology is to identify novel genomic drivers of solid tumors and developing precision treatments that target them. ERBB2 amplification is an established therapeutic target in breast and gastric cancers, but efforts to translate this finding to other solid tumors with ERBB2 amplification have not been effective. Recently the focus has turned to targeting activating ERBB2 mutations. The year 2018 marked an important milestone in establishing ERBB2 mutation as an important actionable target in multiple cancer types. There have been several recent preclinical and clinical studies evaluating ERBB2 mutation as a therapeutic target with varying success. With increasing access to next-generation sequencing technologies in the clinic, oncologists are frequently identifying activating ERBB2 mutations in patients with cancer. There is a significant need both from the clinician and bench scientist perspectives to understand the current state of affairs for ERBB2 mutations.

Reversible Restrictive Lung Disease in Pseudomesotheliomatous Carcinoma in a Lung Harboring a HER2-mutation

Pseudomesotheliomatous carcinoma of the lung is very rare, and reversible restrictive lung disease with pseudomesotheliomatous carcinoma has not yet been previously reported. We herein report a patient with HER2-positive non-small-cell lung cancer (NSCLC) showing pseudomesotheliomatous carcinoma who was successfully treated with bevacizumab combination chemotherapy. A 56-year-old Japanese woman with advanced NSCLC presented with dyspnea. We administered chemotherapy with cisplatin (75 mg/m²) plus pemetrexed (500 mg/m²) plus bevacizumab (15 mg/kg), followed by pemetrexed plus bevacizumab. After eight cycles of maintenance chemotherapy, chest CT demonstrated a marked tumor reduction and an improvement of the right lung volume. The vital capacity was thereafter found to have significantly increased according to pulmonary function tests.

The localization of pre mRNA splicing factor PRPF38B is a novel prognostic biomarker that may predict survival benefit of trastuzumab in patients with breast cancer overexpressing HER2

Cancer biomarkers that can define disease status and provide a prognostic insight are essential for the effective management of patients with breast cancer (BC).

The prevalence, clinicopathological and prognostic significance of PRPF38B expression in a consecutive series of 1650 patients with primary invasive breast carcinoma were examined using immunohistochemistry. Furthermore, the relationship(s) between clinical outcome and PRPF38B expression was explored in 627 patients with ER-negative (oestrogen receptor) disease, and 322 patients with HER2-overexpressing disease.

Membranous expression of PRPF38B was observed in 148/1388 (10.7%) cases and was significantly associated with aggressive clinicopathological features, including high grade, high mitotic index, pleomorphism, invasive ductal carcinoma of no specific type (IDC-NST), ER-negative, HER2-overexpression and p53 mutational status (all p < 0.01). In patients with ER-negative disease receiving chemotherapy, nuclear expression of PRPF38B was significantly associated with a reduced risk of relapse (p = 0.0004), whereas membranous PRPF38B expression was significantly associated with increased risk of relapse (p = 0.004; respectively) at a 5 year follow-up. When patients were stratified according to ER-negative/HER2-positive status, membranous PRPF38B expression was associated with a higher risk of relapse in those patients that did not receive trastuzumab therapy (p = 0.02), whereas in those patients with ER-negative/HER2-positive disease that received trastuzumab adjuvant therapy, membranous PRPF38B expression associated with a lower risk of relapse (p = 0.00018).

Nuclear expression of PRPF38B is a good prognostic indicator in both ER-negative patients and ER-negative/HER2-positive BC (breast cancer) patients, whereas membranous localisation of PRPF38B is a poor prognostic biomarker that predicts survival benefit from trastuzumab therapy in patients with ER-negative/HER2-overexpressing BC.

Activating HER2 mutations as emerging targets in multiple solid cancers

The epidermal growth factor receptor (EGFR) family of transmembrane receptor tyrosine kinases activates signalling pathways regulating cellular proliferation and survival. HER2 is a non-ligand-binding member of this family and exerts its activity through heterodimerisation with other EGFR family members. HER2 functional activation promotes oncogenesis, leading to the investigation of HER2-directed agents in cancers with HER2 alterations. This has been best characterised in the context of HER2 gene amplification in breast and gastro-oesophageal cancers, for which HER2-directed drugs form part of standard treatment regimens. More recently, somatic HER2 gene mutations have been detected in a range of human cancer types. Preclinical data suggest that functionally activating HER2 mutations may drive and maintain cancers in a manner analogous to HER2 gene amplification and that HER2 mutations may similarly confer sensitivity to HER2-directed drugs. Here, we critically review the emerging roles for HER2-directed drugs in HER2 mutant cancers. We review data from experimental models, where our knowledge of the underlying biology of HER2 mutational activation remains incomplete. We discuss clinical data from Phase I and II clinical trials which evaluate HER2-directed agents (tyrosine kinase inhibitors and antibody-based drugs) in several cancer types. We highlight the heterogeneity of HER2 mutations in human cancers, differences in the clinical efficacy of HER2-directed drugs between cancer types and possible mechanisms of primary and acquired resistance, in order to guide clinical practice and future drug development.

HER2 mutations in lung adenocarcinomas: A report from the Lung Cancer Mutation Consortium

BACKGROUND

Human epidermal growth factor receptor 2 (HER2) mutations have been reported in lung adenocarcinomas. Herein, the authors describe the prevalence, clinical features, and outcomes associated with HER2 mutations in 1007 patients in the Lung Cancer Mutation Consortium (LCMC).

METHODS

Patients with advanced-stage lung adenocarcinomas were enrolled to the LCMC. Tumor specimens were assessed for diagnosis and adequacy; multiplexed genotyping was performed in Clinical Laboratory Improvement Amendments (CLIA)-certified laboratories to examine 10 oncogenic drivers. The LCMC database was queried for patients with HER2 mutations to access demographic data, treatment history, and vital status. An exploratory analysis was performed to evaluate the survival of patients with HER2 mutations who were treated with HER2-directed therapies.

RESULTS

A total of 920 patients were tested for HER2 mutations; 24 patients (3%) harbored exon 20 insertion mutations (95% confidence interval, 2%-4%). One patient had a concurrent mesenchymal-epithelial transition factor (MET) amplification. The median age of the patients was 62 years, with a slight predominance of females over males (14 females vs 10 males). The majority of the patients were never-smokers (71%) and presented with advanced disease at the time of diagnosis. The median survival for patients who received HER2-targeted therapies (12 patients) was 2.1 years compared with 1.4 years for those who did not (12 patients) (P = .48). Patients with HER2 mutations were found to have inferior survival compared with the rest of the LCMC cohort with other mutations: the median survival was 3.5 years in the LCMC population receiving targeted therapy and 2.4 years for patients not receiving targeted therapy.

CONCLUSIONS

HER2 mutations were detected in 3% of patients with lung adenocarcinoma in the LCMC. HER2-directed therapies should be investigated in this subgroup of patients. Cancer 2017;123:4099-4105. © 2017 American Cancer Society.

Strategies to Overcome Bypass Mechanisms Mediating Clinical Resistance to EGFR Tyrosine Kinase Inhibition in Lung Cancer

The vast majority of patients with metastatic lung cancers who initially benefit from EGFR-targeted therapies eventually develop resistance. An increasing understanding of the number and complexity of resistance mechanisms highlights the challenge of treating tumors resistant to EGFR inhibitors. Resistance mechanisms include new, second-site mutations within EGFR (e.g., T790M and C797S), upregulation of MET kinase, upregulation of insulin growth factor receptor (IGFR), HER2 amplification, increased expression of AXL, BIM modulation, NF-κB activation, histologic switch to small-cell cancer, epithelial-to-mesenchymal transition, PDL1 expression with subsequent immune tolerance, and release of cytokines such as TGFβ and IL6. Herein, we review the growing body of knowledge regarding EGFR bypass pathways, and the development of new drugs and combination treatment strategies to overcome resistance. Mol Cancer Ther; 16(2); 265-72. ©2017 AACR.

Triplet therapy with afatinib, cetuximab, and bevacizumab induces deep remission in lung cancer cells harboring EGFR T790M in vivo

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have changed the treatment strategy for EGFR‐mutant lung cancers; however, resistance usually occurs due to a secondary mutation, T790M, in EGFR. Combination therapy using afatinib and cetuximab has had good results in lung tumors harboring EGFR^T790M mutations in clinical trials. The effect of bevacizumab, an antivascular endothelial growth factor (VEGF) antibody, combined with EGFR‐TKIs has also been investigated. We hypothesized that the dose of afatinib and cetuximab could be reduced by combination with bevacizumab and that the triplet therapy may result in better tumor inhibition with tolerable toxicity. Using a xenograft mouse model with H1975‐harboring EGFR^L858R+T790M and RPC‐9‐harboring EGFR^19DEL+T790M, we tested the efficacy of the triplet therapy with a modified dose of afatinib, cetuximab, and bevacizumab, and compared this therapy to single and double therapies. Triplet therapy with afatinib, cetuximab, and bevacizumab induced pathological complete remission in xenograft tumors with H1975 and RPC‐9 cells versus tumors treated with single or double therapies. We saw no body weight loss in the mice. The triple therapy induced a significant reduction in CD31‐positive vascular endothelial cells and increased cleaved caspase‐3‐positive cells in the tumors. This suggests that one mechanism underlying the deep remission could be suppression of neovascularization and induction of apoptosis by intensive inhibition of driver oncoproteins and VEGF. These results highlight the potential of afatinib, cetuximab, and bevacizumab to induce deep remission in tumors harboring EGFR^T790M mutations. Therefore, clinical trials of this combination therapy are warranted.

Alterations in genes other than EGFR/ALK/ROS1 in non-small cell lung cancer: trials and treatment options

During the last decade, we have seen tremendous progress in the therapy of lung cancer. Discovery of actionable mutations in EGFR and translocations in ALK and ROS1 have identified subsets of patients with excellent tumor response to oral targeted agents with manageable side effects. In this review, we highlight treatment options including corresponding clinical trials for oncogenic alterations affecting the receptor tyrosine kinases MET, FGFR, NTRK, RET, HER2, HER3, and HER4 as well as components of the RAS-RAF-MEK signaling pathway.

[Role of HER2 in NSCLC]

过去几年中, 随着分子靶向药物的引入, 非小细胞肺癌(non-small cell lung cancer, NSCLC)的药物治疗策略发生了巨大变化, 向基于组织学和分子水平的治疗手段转变。表皮生长因子受体(epidermal growth factor receptor, EGFR)突变、Kirsten鼠肉瘤(Kirsten rat sarcoma, KRAS)癌基因突变、间变淋巴瘤激酶(anaplastic lymphoma kinase, ALK)重排等的发现, 影响着NSCLC治疗的发展。最近, 对人表皮生长因子受体2(human epidermal growth factor receptor 2, HER2)研究重燃兴趣, 这一基因改变与NSCLC对不同酪氨酸激酶抑制剂(tyrosine kinase inhibitors, TKIs)的敏感性相关, 其具有可能的预测作用, HER2扩增可能是EGFR突变肿瘤对EGFR-TKIs获得性耐药的机制之一。其次, HER2突变可能阐明一条新的靶向治疗NSCLC的策略。本文将对NSCLC中HER2异常调节发挥的作用做一简要介绍。

The Conundrum of Genetic "Drivers" in Benign Conditions

Advances in deep genomic sequencing have identified a spectrum of cancer-specific passenger and driver aberrations. Clones with driver anomalies are believed to be positively selected during carcinogenesis. Accumulating evidence, however, shows that genomic alterations, such as those in BRAF, RAS, EGFR, HER2, FGFR3, PIK3CA, TP53, CDKN2A, and NF1/2, all of which are considered hallmark drivers of specific cancers, can also be identified in benign and premalignant conditions, occasionally at frequencies higher than in their malignant counterparts. Targeting these genomic drivers can produce dramatic responses in advanced cancer, but the effects on their benign counterparts are less clear. This benign-malignant phenomenon is well illustrated in studies of BRAF V600E mutations, which are paradoxically more frequent in benign nevi (∼80%) than in dysplastic nevi (∼60%) or melanoma (∼40%-45%). Similarly, human epidermal growth factor receptor 2 is more commonly overexpressed in ductal carcinoma in situ (∼27%-56%) when compared with invasive breast cancer (∼11%-20%). FGFR3 mutations in bladder cancer also decrease with tumor grade (low-grade tumors, ∼61%; high-grade, ∼11%). “Driver” mutations also occur in nonmalignant settings: TP53 mutations in synovial tissue from rheumatoid arthritis and FGFR3 mutations in seborrheic keratosis. The latter observations suggest that the oncogenicity of these alterations may be tissue context–dependent. The conversion of benign conditions to premalignant disease may involve other genetic events and/or epigenetic reprogramming. Putative driver mutations can also be germline and associated with increased cancer risk (eg, germline RAS or TP53 alterations), but germline FGFR3 or NF2 abnormalities do not predispose to malignancy. We discuss the enigma of genetic “drivers” in benign and premalignant conditions and the implications for prevention strategies and theories of tumorigenesis.

NSCLC and HER2: between lights and shadows

The therapeutic landscape of non-small-cell lung cancer (NSCLC) has dramatically changed in the last few years with the introduction of molecularly targeted agents, leading to unprecedented results in lung tumors with a paradigmatic shift from a "one size fits all" approach to an histologic and molecular-based approach. The discovery of epidermal growth factor receptor (EGFR) mutations in NSCLC in 2004 and the marked response to the EGFR tyrosine kinase inhibitor gefitinib, in a small subset of patients harboring these genetic abnormalities, stimulated the study of other kinase mutants involvement in NSCLC. The incredible story of ALK rearranged tumors, with the rapid Food and Drug Administration approval of Crizotinib after only 4 years from the discovery of EML4-ALK translocation in NSCLC, has profoundly influenced the concept of drug development in NSCLC, paving the way to a novel series of molecularly selected studies with specific inhibitors. The identification of these oncogenic drivers has dramatically changed the genetic landscape of NSCLC moving away from the old concept of a large indistinct histological entity to a combination of rare clinically relevant molecular subsets. Recently, a renewed interest has been emerging on the human epidermal growth factor-2 (HER2) pathway. Genetic aberrations of this signaling pathway have been reported over time to be associated in NSCLC with different sensitivity to the EGFR tyrosine kinase inhibitors, to have a possible prognostic role and more recently HER2 amplification has been emerged as a possible mechanism in EGFR-mutated tumors of acquired resistance to the EGFR tyrosine kinase inhibitors. In addition, dysregulation of the HER2 pathway, in particular HER2 mutations (mostly, in-frame exon 20 insertions), may represent a possible novel therapeutic target in NSCLC, paving the way for a new generation of targeted agents in NSCLC. Since anecdotal case reports of clinical activity of anti-HER2 agents in NSCLC patients with HER2 mutations, several targeted agents have been evaluated in HER2-mutated patients, generating a growing interest upon this oncogenic driver, leading to the design of molecularly selected trials with anti-HER2 compounds and the rediscover of hastily thrown out drugs, such as neratinib. The aim of this article is to provide an overview of the role of HER2 dysregulation in NSCLCs, trying to throw a light not only on the strengths but also the weaknesses of the studies conducted so far. It is a long way to the clinical implementation of these biomarkers and probably the increasing use of next generation sequencing techniques, the creation of large multi-institutional molecular testing platforms and the design of rationally based trials can get closer personalized medicine in NSCLC.

Molecular profiling and the reclassification of cancer: divide and conquer

Cancer is one of the leading causes of mortality in the world. Choosing the best treatment is dependent on making the right diagnosis. The diagnostic process has been based on light microscopy and the identification of the organ of tumor origin. Yet we now know that cancer is driven by molecular processes, and that these do not necessarily segregate by organ of origin. Fortunately, revolutionary changes in technology have enabled rapid genomic profiling. It is now apparent that neoplasms classified uniformly (e.g., non-small cell lung cancer) are actually comprised of up to 100 different molecular entities. For instance, tumors bearing ALK alterations make up about 4% of non-small cell lung cancers, and tumors bearing epidermal growth factor receptor (EGFR) mutations, approximately 5% to 10%. Importantly, matching patients to therapies targeted against their driver molecular aberrations has resulted in remarkable response rates. There is now a wealth of evidence supporting a divide-and-conquer strategy. Herein, we provide a concise primer on the current state-of-the-art of molecular profiling in the cancer clinic.

Analysis of different HER-2 mutations in breast cancer progression and drug resistance

Studies over the last two decades have identified that amplified human epidermal growth factor receptor (HER‐2; c‐erbB‐2, neu) and its overexpression have been frequently implicated in the carcinogenesis and prognosis in a variety of solid tumours, especially breast cancer. Lots of painstaking efforts were invested on the HER‐2 targeted agents, and significantly improved outcome and prolonged the survival of patients. However, some patients classified as ‘HER‐2‐positive’ would be still resistant to the anti‐HER‐2 therapy. Various mechanisms of drug resistance have been illustrated and the alteration of HER‐2 was considered as a crucial mechanism. However, systematic researches in regard to the HER‐2 mutations and variants are still inadequate. Notably, the alterations of HER‐2 play an important role in drug resistance, but also have a potential association with the cancer risk. In this review, we summarize the possible mutations and focus on HER‐2 variants’ role in breast cancer tumourigenesis. Additionally, the alteration of HER‐2, as a potential mechanism of resistance to trastuzumab, is discussed here. We hope that HER‐2 related activating mutations could potentially offer more therapeutic opportunities to a broader range of patients than previously classified as HER‐2 overexpressed.

HER2 expression status in diverse cancers: review of results from 37,992 patients

Human epidermal growth factor receptor 2 (HER2) amplification/overexpression is an effective therapeutic target in breast and gastric cancer. Although HER2 positivity has been reported in other malignancies, previous studies generally focused on one cancer type, making it challenging to compare HER2 positivity across studies/malignancies. Herein, we examined 37,992 patient samples for HER2 expression (+/- amplification) in a single laboratory. All 37,992 patients were tested by immunohistochemistry (IHC); 21,642 of them were also examined for HER2 amplification with either fluorescent in situ hybridization (FISH) (11,670 patients) or chromogenic in situ hybridization (CISH) (9,972 patients); 18,262 patients had tumors other than breast or gastric cancer. All tissues were analyzed in a Clinical Laboratory Improvement Amendments (CLIA) laboratory (Caris Life Sciences) at the request of referring physicians. HER2 protein overexpression was found in 2.7 % of samples. Over-expressed HER2 was detected predominantly in malignancies of epithelial origin; for cancers derived from mesenchyme, neuroendocrine tissue, central nervous system, and kidney, HER2 expression and amplification were remarkably rare or non-existent. Bladder carcinomas, gallbladder, extrahepatic cholangiocarcinomas, cervical, uterine, and testicular cancers showed HER2 positivity rates of 12.4, 9.8, 6.3, 3.9, 3.0, and 2.4 %, respectively. HER2 overexpression and/or amplification is frequently found across tumor types. These observations may have significant therapeutic implications in cancers not traditionally thought to benefit from anti-HER2 therapies.

Promising Targets and Current Clinical Trials in Metastatic Non-Squamous NSCLC

Lung adenocarcinoma is the most common subtype of lung cancer today. With the discovery of epidermal growth factor receptor (EGFR) mutations, anaplastic lymphoma kinase (ALK) rearrangements, and effective targeted therapy, personalized medicine has become a reality for patients with lung adenocarcinoma. Here, we review potential additional targets and novel therapies of interest in lung adenocarcinoma including targets within the cell surface (receptor tyrosine kinases EGFR, human epidermal growth factor receptor 2, RET, ROS1, mesenchymal-epidermal transition, TRK), targets in intracellular signal transduction (ALK, RAS-RAF-MEK, PI3K-AKT-PTEN, WNT), nuclear targets such as poly-ADP ribose polymerase, heat shock protein 90, and histone deacetylase, and selected pathways in the tumor environment. With the evolving ability to identify specific molecular aberrations in patient tumors in routine practice, our ability to further personalize therapy in lung adenocarcinoma is rapidly expanding.

Molecular docking studies shows tivozanib and lapatinib as potential inhibitors of EML4-ALK translocation mediated fusion protein in non small cell lung cancer

Identification of activating mutations in non-small cell lung cancers (NSCLC) has been a focus in recent years. This led to successful evidence of using tyrosine kinase inhibitors (TKIs) over the standard platinum doublet based chemotherapy as the first line treatment in the metastatic setting.The rearrangements of fusion protein EML4-ALK in NSCLC lead to the use of crizotinib for this class of tumors. Preclinical and Phase 1 clinical studies show that ceritinib is more effective against both crizotinib sensitive and resistant tumors. Although robust responses to crizotinib are observed in NSCLC harboring ALK mutations, majority of tumors eventually become resistant, posing a major challenge in treatment course. Thus, there is a need for the identification and development of second-generation of ALK inhibitors. Computer aided molecular docking data show Tivozanib and Lapatinib bind EML4-ALK with high score. Tivozanib is in clinical trials for renal cell cancer and Lapatinib is a known dual tyrosine kinase inhibitor effective in breast cancer patients with HER2 over-expression. Additional data on these compounds for use in EML4-ALK positive NSCLC will provide evidence for use in patients treated with crizotinib. Data shows the importance of computer aided molecular docking in developing candidates with improved activity for further consideration in vitro and in vivo validation.

A framework for genomic biomarker actionability and its use in clinical decision making

The increasing scope and availability of genetic testing options for patients suffering from cancer has raised questions about how to use results of molecular diagnostics to inform patient care. For some biomarkers (e.g. BRAF mutations in melanoma), standards exist that outline treatments for individuals harboring aberrations in the biomarker; however for the vast majority of genomic abnormalities, few guidelines exist. Clinical decision making and the therapeutic approach for a patient with a given cancer characterized by aberrations in different genes may be aided by the use of a biomarker actionability framework that provides levels of evidence regarding whether and how a molecular abnormality can be considered a therapeutically relevant biomarker. A gene may be considered theoretically actionable if it has a basis of actionability, such that clinically available drugs can target a gene product that drives the cancer or is differentially expressed in tumor versus normal elements. Herein, we discuss a possible framework for developing guidelines for actionability, as they relate to genomically-based cancer therapeutics.

A phase I trial of combination trastuzumab, lapatinib, and bevacizumab in patients with advanced cancer

PURPOSE

Preclinical data indicate that combination HER2-directed and anti-VEGF therapy may bypass resistance to trastuzumab. A phase I trial was performed to assess safety, activity, and correlates.

EXPERIMENTAL DESIGN

Patients with advanced, refractory malignancy were enrolled (modified 3 + 3 design with expansions for responding tumor types). Patients received lapatinib daily for 21 days, and bevacizumab and trastuzumab every 3 weeks. Correlates included HER2 extracellular domain levels (ECD) and single nucleotide polymorphisms (SNPs).

RESULTS

Ninety-four patients were treated (median = four prior systemic therapies). The most common related adverse events ≥ grade 2 were diarrhea (n = 33, 35 %) and hypertension (n = 10, 11 %). The recommended phase 2 dose was trastuzumab 6 mg/m(2) (loading = 8 mg/m(2)) and bevacizumab 15 mg/kg every 3 weeks, with lapatinib 1,250 mg daily (full FDA-approved dose of each drug). One patient (1 %) achieved a complete response (CR); eight (9 %), a partial response (PR) (includes breast (n = 7, one of which was HER2 2+ by IHC) and salivary ductal carcinoma (n = 1); and 14 (15 %), stable disease (SD) ≥6 months (total SD ≥ 6 months/PR/CR =23 (25 %). All patients with PR/CR received prior trastuzumab +/- lapatinib. SD ≥ 6 months/PR/CR rate and time to treatment failure (TTF) correlated with elevated baseline HER2 ECD (N = 75 patients tested) but not with HER2 SNPs.

CONCLUSIONS

Combination trastuzumab, lapatinib, and bevacizumab was well-tolerated and demonstrated antitumor activity in heavily pretreated patients with advanced malignancy.

HER2 aberrations in cancer: implications for therapy

Although anti-HER2 (human epidermal growth factor receptor 2) therapy is currently approved for breast, gastric, and gastroesophageal cancers overexpressing the HER2 protein or amplified for the HER2 gene, HER2 aberrations (gene amplification, gene mutations, and protein overexpression) are reported in other diverse malignancies. Indeed, about 1-37% of tumors of the following types harbor HER2 aberrations: bladder, cervix, colon, endometrium, germ cell, glioblastoma, head and neck, liver, lung, ovarian, pancreas, and salivary duct. Four HER2-targeted therapies have been approved for HER2-positive breast cancer: two antibodies (trastuzumab and pertuzumab), an antibody-drug conjugate (ado-trastuzumab emtansine), and a small molecule kinase inhibitor (lapatinib). In addition, afatinib, a small molecule kinase inhibitor that causes irreversible inhibition of EGFR (epidermal growth factor receptor) and HER2, was recently approved for EGFR-mutated non-small cell lung cancer. A large number of novel HER2-targeted agents are also in clinical trials. Herein we discuss the state of the art in understanding and targeting HER2 across anatomic tumor types.