An EGFR signature predicts cell line and patient sensitivity to multiple tyrosine kinase inhibitors

EGFR is an oncogene with a high frequency of activating mutations in nonsmall cell lung cancer (NSCLC). EGFR inhibitors have been FDA-approved for NSCLC and have shown efficacy in patients with certain EGFR mutations. However, only 9% to 26% of these patients achieve objective responses. In our study, we developed an EGFR gene signature based on The Cancer Genome Atlas (TCGA) RNA-seq data of lung adenocarcinoma (LUAD) to direct the preselection of patients for more effective EGFR-targeted therapy. This signature infers baseline EGFR signaling pathway activity (denoted as EGFR score) in tumor samples, which is associated with tumor sensitivity to EGFR inhibitors and other tyrosine kinase inhibitors (TKIs). EGFR score predicted sensitivity of lung cancer cell lines to Erlotinib, Gefitinib and Sorafenib. Importantly, EGFR score calculated from pretreated samples was associated with patient response to Gefitinib and Sorafenib in lung cancer. Additionally, integration of the EGFR signature with TCGA LUAD data showed that it accurately predicted functional effects of different somatic EGFR mutations, and identified other mutations affecting EGFR pathway activity. Finally, using cancer cell line and clinical trial data, the EGFR score was associated with patient response to TKIs in liver cancer and other cancer types. The EGFR signature provides a useful biomarker that can expand the application of EGFR inhibitors or other TKIs and improve their treatment efficacy through patient stratification.     

Current role of EGF receptor monoclonal antibodies and tyrosine kinase inhibitors in the management of head and neck squamous cell carcinoma

New agents and treatment strategies that can be safely and effectively integrated into current treatment paradigms for head and neck squamous cell carcinoma (HNSCC) are urgently needed. To date, the anti-EGF receptor (EGFR) monoclonal antibody, cetuximab, is the first and only molecularly targeted therapy to demonstrate a survival benefit for patients with recurrent or metastatic disease. Other anti-EGFR-targeted therapies, including monoclonal antibodies (e.g., panitumumab and zalutumumab) and reversible and irreversible ErbB family tyrosine kinase inhibitors (e.g., lapatinib, afatinib and dacomitinib) are being actively investigated in Phase II and Phase III clinical trials. In addition, validated biomarkers are needed to predict clinical benefit and resistance to anti-EGFR therapy in HNSCC. This review will compare and contrast the mechanisms of action of anti-EGFR monoclonal antibodies and tyrosine kinase inhibitors and also discuss their role in the management of HNSCC and the potential impact of human papillomavirus status in the development of these targeted agents.     

Erlotinib (Tarceva®): a promising drug targeting epidermal growth factor receptor tyrosine kinase

Overexpression of the epidermal growth factor receptor (EGFR) is correlated with a poor prognosis in several human malignancies. In addition, cancers overexpressing EGFR respond poorly to both chemotherapy and radiation therapy. Therefore, EGFR is a viable target for cancer therapy. This review will address how EGFR blockade modulates signal transduction, leading to alterations in the cell cycle progression with secondary inhibition of proliferation and differentiation of cancer cells. As a prototypical example, erlotinib (Tarceva^®), a reversible EGFR tyrosine kinase inhibitor will be discussed. This drug has demonstrated promising antitumor activity in Phase II trials in several solid tumors and definitive Phase III studies to demonstrate clinical benefit have completed accrual.     

Epidermal growth factor receptor tyrosine kinase inhibitors

Activation of the epidermal growth factor receptor (EGFR) has been linked to tumour proliferation, invasion, metastasis and angiogenesis in epithelial tumours. Inhibitors of the EGFR have emerged as promising anticancer agents and two main approaches have been developed, humanised monoclonal antibodies and tyrosine kinase inhibitors. This review discusses the current status of EGFR tyrosine kinase inhibitors (EGFR-TKIs) that have entered clinical development. EGFR-TKIs are generally well tolerated and can sometimes produce impressive tumour regression in patients with advanced non-small-cell lung cancer. However, highly predictive or surrogate markers of activity have not been identified and there remains a need for translational research in their future development.     

Successful pregnancy with epidermal growth factor receptor tyrosine kinase inhibitor treatment of metastatic lung adenocarcinoma presenting with respiratory failure

We report a woman presenting with respiratory failure due to a right-sided pleural effusion, lung metastases and lymphangitis carcinomatosis from advanced lung adenocarcinoma in the third trimester of pregnancy, who showed good response to EGFR tyrosine kinase inhibitor.     

Immediate versus delayed treatment with EGFR tyrosine kinase inhibitors after first-line therapy in advanced non-small-cell lung cancer

Objective: To analyze the outcomes of patients who received TKI immediately after the first-line without progression as maintenance treatment (immediate group) vs. those received delayed treatment upon disease progression as second-line therapy (delayed group). Methods: The study included 159 no-small-cell lung cancer (NSCLC) patients who received gefitinib or erlotinib as maintenance treatment in the immediate group (85 patients) or as second-line therapy in the delayed group (74 patients). The primary end...     

Role of tyrosine kinase inhibitors in the management of high-grade gliomas

Recent years have witnessed an explosion of promising therapies for cancer patients. New insights into the biology of malignancies have led to the development of targeted agents with the potential to improve survival and quality of life. One of the most important classes of these compounds are tyrosine kinase inhibitors. These agents are beginning to offer a clinically relevant benefit to patients with tumors that until recently have been refractory to medical therapies. High-grade gliomas represent one class of medically refractory solid tumors. This article summarizes the state of the art of tyrosine kinase inhibitors in the management of patients with high-grade gliomas.     

Tyrosine kinase inhibitors

Membrane receptors with tyrosine kinase activity and cytoplasmic tyrosine kinases have emerged as important potential targets in oncology. Starting from basic structures such as anilino-quinazoline, numerous compounds have been synthesised, with the help of tyrosine kinase crystallography, which has allowed to optimise protein-ligand interactions. The catalytic domains of all kinases present similar three-dimensional structures, which explains that it may be difficult to identify molecules having a high specificity for a given tyrosine kinase. Some tyrosine kinase inhibitors are relatively specific for epidermal growth factor receptor (EGFR) such as géfitinib and erlotinib; other are mainly active against platelet-derived growth factor receptor (PDGFR) and the receptor KIT, such as imatinib or nilotinib, and other against vascular endothelial growth factor (VEGF) receptors involved in angiogenesis, such as sunitinib and sorafenib. The oral formulation of tyrosine kinase inhibitors is well accepted by the patients but may generate sometimes compliance problems requiring pharmacokinetic monitoring. This chemical family is in full expansion and several dozens of compounds have entered clinical trials.     

Variability in organ-specific EGFR mutational spectra in tumour epithelium and stroma may be the biological basis for differential responses to tyrosine kinase inhibitors

Organ-specific differences in epidermal growth factor receptor (EGFR) mutational spectra and frequencies were found in lung cancer and sporadic and BRCA1/2-related breast cancers. Additionally, we found a high frequency of EGFR mutations in the tumour stroma of these invasive breast carcinomas. Those organ-specific mutational spectra and potential targets in the cancer-associated stroma might influence the efficacy of TKI therapy.     

In vitro modeling to determine mutation specificity of EGFR tyrosine kinase inhibitors against clinically relevant EGFR mutants in non-small-cell lung cancer

EGFR mutated lung cancer accounts for a significant subgroup of non-small-cell lung cancer (NSCLC). Over the last decade, multiple EGFR tyrosine kinase inhibitors (EGFR-TKIs) have been developed to target mutated EGFR. However, there is little information regarding mutation specific potency of EGFR-TKIs against various types of EGFR mutations. The purpose of this study is to establish an in vitro model to determine the “therapeutic window” of EGFR-TKIs against various types of EGFR mutations, including EGFR exon 20 insertion mutations. The potency of 1^st (erlotinib), 2^nd (afatinib) and 3^rd (osimertinib and rociletinib) generation EGFR-TKIs was compared in vitro for human lung cancer cell lines and Ba/F3 cells, which exogenously express mutated or wild type EGFR. An in vitro model of mutation specificity was created by calculating the ratio of IC50 values between mutated and wild type EGFR. The in vitro model identified a wide therapeutic window of afatinib for exon 19 deletions and L858R and of osimertinib and rociletinib for T790M positive mutations. The results obtained with our models matched well with previously reported preclinical and clinical data. Interestingly, for EGFR exon 20 insertion mutations, most of which are known to be resistant to 1^st and 2^nd generation EGFR-TKIS, osimertinib was potent and presented a wide therapeutic window. To our knowledge, this is the first report that has identified the therapeutic window of osimertinib for EGFR exon 20 insertion mutations. In conclusion, this model will provide a preclinical rationale for proper selection of EGFR-TKIs against clinically-relevant EGFR mutations.     

受体酪氨酸激酶AXL在肿瘤中的研究进展

AXL是TAM受体酪氨酸激酶家族中的一员,AXL已经被证实与肺癌、乳腺癌、甲状腺癌、前列腺癌和胰腺癌等多种癌症有关.最新证据显示,AXL可促进多种肿瘤的生长、侵袭、转移,其抑制剂可抑制肿瘤形成,这说明AXL可能成为抗肿瘤治疗的潜在靶点,AXL激酶抑制剂的应用可能成为抗肿瘤治疗的新策略.本文对AXL与肿瘤方向的研究进展做一综述.     

Management of diarrhea induced by epidermal growth factor receptor tyrosine kinase inhibitors

Treatment for non-small-cell lung cancer (nsclc) is moving away from traditional chemotherapy toward personalized medicine. The reversible tyrosine kinase inhibitors (tkis) erlotinib and gefitinib were developed to target the epidermal growth factor receptor (egfr). Afatinib, an irreversible ErbB family blocker, was developed to block egfr (ErbB1), human epidermal growth factor receptor 2 (ErbB2), and ErbB4 signalling, and transphosphorylation of ErbB3. All of the foregoing agents are efficacious in treating nsclc, and their adverse event profile is different from that of chemotherapy. Two of the most common adverse events with egfr tkis are rash and diarrhea. Here, we focus on diarrhea. The key to successful management of diarrhea is to treat early and aggressively using patient education, diet, and antidiarrheal medications such as loperamide. We also present strategies for the effective assessment and management of egfr tki–induced diarrhea.     

Incidence and relevance of QTc-interval prolongation caused by tyrosine kinase inhibitors

Background:

Tyrosine kinase inhibitors (TKIs) are associated with prolongation of the QTc interval on the electrocardiogram (ECG). The QTc-interval prolongation increases the risk of life-threatening arrhythmias. However, studies evaluating the effects of TKIs on QTc intervals are limited and only consist of small patient numbers.

Methods:

In this multicentre trial in four centres in the Netherlands and Italy we screened all patients who were treated with any TKI. To evaluate the effects of TKIs on the QTc interval, we investigated ECGs before and during treatment with erlotinib, gefitinib, imatinib, lapatinib, pazopanib, sorafenib, sunitinib, or vemurafenib.

Results:

A total of 363 patients were eligible for the analyses. At baseline measurement, QTc intervals were significantly longer in females than in males (QTc_females=404 ms vs QTc_males=399 ms, P=0.027). A statistically significant increase was observed for the individual TKIs sunitinib, vemurafenib, sorafenib, imatinib, and erlotinib, after the start of treatment (median ΔQTc ranging from +7 to +24 ms, P<0.004). The CTCAE grade for QTc intervals significantly increased after start of treatment (P=0.0003). Especially patients who are treated with vemurafenib are at increased risk of developing a QTc of ⩾470 ms, a threshold associated with an increased risk for arrhythmias.

Conclusions:

These observations show that most TKIs significantly increase the QTc interval. Particularly in vemurafenib-treated patients, the incidence of patients at risk for arrhythmias is increased. Therefore, especially in case of combined risk factors, ECG monitoring in patients treated with TKIs is strongly recommended.     

Simultaneous targeting of Src kinase and receptor tyrosine kinase results in synergistic inhibition of renal cell carcinoma proliferation and migration

There have been recent improvements in the treatment for metastatic renal cell carcinoma (RCC) with receptor tyrosine kinase (RTK) inhibitors being one of newer treatment options. We hypothesized that simultaneous targeting of Src kinase and the RTK may have synergistic effects to further improve therapies on metastatic RCC. The effects of Src kinase inhibitor saracatinib and multiple RTK inhibitor sunitinib on RCC cell line (ACHN) and Caki-1 were studied. Saracatinib alone or in combination with sunitinib inhibited the migration of ACHN and Caki-1 cells in vitro. Activation of migration related components FAK, P130Cas and Paxillin were blocked by saracatinib at 0.05- to 3-μM concentrations. Combined treatment resulted in improved growth inhibition, greater loss of the S phase cell population and decreased clonogenic colony formation compared to sunitinib alone in the metastatic Caki-1 line. Molecular studies in Caki-1 showed that saracatinib alone and in combination with sunitinib inhibited phosphorylation of the cell progression regulator c-Myc in a dose-dependent manner. Sunitinib alone or in combination suppressed cyclin-D1 expression with the combination showing greater dose-dependent effect. Sunitinib inhibited vascular endothelial growth factor (VEGF) secretion through the inhibition of STAT3 signaling and VEGF biosynthesis. HIF1-α expression in normoxic and hypoxic conditions in Caki-1 cells was inhibited by either saracatinib or sunitinib when administered alone, however, a greater reduction occurred when these compounds were given in combination. Targeting Src kinase and RTK simultaneously with saracatinib and sunitinib resulted in 70-80% blockade of RCC cell migration, synergistic inhibition of cell growth and reduction of acquired drug resistance in Caki-1 cells. The results show promise for combination targeted therapy of RCC.     

表皮生长因子受体与酪氨酸激酶抑制剂在肿瘤防治中的应用进展

表皮生长因子受体(epidermal growth factor receptor,EGFR)信号传递系统可调控细胞周期，调节细胞生长与分化，促进损伤修复。EGFR在包括非小细胞肺癌(non-small-cell lung cancer,NSCLC)在内的多种上皮源性肿瘤中过表达预示存活率低、预后差、转移可能性大，可作为肿瘤基因治疗的靶位。酪氨酸激酶抑制剂(tyrosine kinase inhibitors，TKIs)可选择性抑制EGFR酪氨酸激酶活性，抑制肿瘤生长，增加放化疗敏感性。     

Lapatinib: a novel dual tyrosine kinase inhibitor

Lapatinib is an active and well-tolerated oral dual tyrosine kinase inhibitor that is able to inhibit epidermal growth factor receptor (EGFR) and HER2 with high specificity. It has shown promising activity in several cancers most notably metastatic breast cancer. Lapatinib is active in both trastuzumab-refractory and -naïve breast cancer and a number of phase III studies are ongoing to fully define its activity. Studies have also been conducted in a range of other cancers including renal cell carcinoma. It is essential that future studies incorporate predictive biomarker subgroup analysis. This will help to ensure that important subgroup activity is not missed and also allow the definition of groups most likely to benefit from lapatinib.     

QTc interval prolongation with vascular endothelial growth factor receptor tyrosine kinase inhibitors

Background:

Multi-targeted vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitors (TKIs) are known to cause cardiac toxicity, but the relative risk (RR) of QTc interval prolongation and serious arrhythmias associated with them are not reported.

Methods:

We conducted a trial-level meta-analysis of randomised phase II and III trials comparing arms with and without a US Food and Drug Administration-approved VEGFR TKI (sunitinib, sorafenib, pazopanib, axitinib, vandetanib, cabozantinib, ponatinib and regorafenib). A total of 6548 patients from 18 trials were selected. Statistical analyses were conducted to calculate the summary incidence, RR and 95% CIs.

Results:

The RR for all-grade and high-grade QTc prolongation for the TKI vs no TKI arms was 8.66 (95% CI 4.92–15.2, P<0.001) and 2.69 (95% CI 1.33–5.44, P=0.006), respectively, with most of the events being asymptomatic QTc prolongation. Respectively, 4.4% and 0.83% of patients exposed to VEGFR TKI had all-grade and high-grade QTc prolongation. On subgroup analysis, only sunitinib and vandetanib were associated with a statistically significant risk of QTc prolongation, with higher doses of vandetanib associated with a greater risk. The rate of serious arrhythmias including torsades de pointes did not seem to be higher with high-grade QTc prolongation. The risk of QTc prolongation was independent of the duration of therapy.

Conclusions:

In the largest study to date, we show that VEGFR TKI can be associated with QTc prolongation. Although most cases were of low clinical significance, it is unclear whether the same applies to patients treated off clinical trials.     

Acquired resistance to EGFR tyrosine kinase inhibitors alters the metabolism of human head and neck squamous carcinoma cells and xenograft tumours

Background:

Acquired resistance to molecularly targeted therapeutics is a key challenge in personalised cancer medicine, highlighting the need for identifying the underlying mechanisms and early biomarkers of relapse, in order to guide subsequent patient management.

Methods:

Here we use human head and neck squamous cell carcinoma (HNSCC) models and nuclear magnetic resonance (NMR) spectroscopy to assess the metabolic changes that follow acquired resistance to EGFR tyrosine kinase inhibitors (TKIs), and which could serve as potential metabolic biomarkers of drug resistance.

Results:

Comparison of NMR metabolite profiles obtained from control (CAL^S) and EGFR TKI-resistant (CAL^R) cells grown as 2D monolayers, 3D spheroids or xenograft tumours in athymic mice revealed a number of differences between the sensitive and drug-resistant models. In particular, we observed elevated levels of glycerophosphocholine (GPC) in CAL^R relative to CAL^S monolayers, spheroids and tumours, independent of the growth rate or environment. In addition, there was an increase in alanine, aspartate and creatine+phosphocreatine in resistant spheroids and xenografts, and increased levels of lactate, branched-chain amino acids and a fall in phosphoethanolamine only in xenografts. The xenograft lactate build-up was associated with an increased expression of the glucose transporter GLUT-1, whereas the rise in GPC was attributed to inhibition of GPC phosphodiesterase. Reduced glycerophosphocholine (GPC) and phosphocholine were observed in a second HNSCC model probably indicative of a different drug resistance mechanism.

Conclusions:

Our studies reveal metabolic signatures associated not only with acquired EGFR TKI resistance but also growth pattern, microenvironment and contributing mechanisms in HNSCC models. These findings warrant further investigation as metabolic biomarkers of disease relapse in the clinic.     

Epidermal growth factor receptor tyrosine kinase inhibitors for non-small cell lung cancer

First-generation epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), including gefitinib and erlotinib, have proven to be highly effective agents for advanced non-small cell lung cancer (NSCLC) in patients harboring an activating EGFR mutation such as the exon 19 deletion mutation and L858R. Although those reversible small molecular targeted agents provide a significant response and survival benefit, all responders eventually acquire resistance. Second-generation EGFR-targeting agents, such as irreversible EGFR/HER2 tyrosine kinase inhibitors and pan-HER TKIs, may improve survival further and be useful for patients who acquired resistance to first-generation EGFR-TKIs. This review discusses novel therapeutic strategies for EGFR-mutated advanced NSCLC using first- and second-generation EGFR-TKIs.