Pharmacokinetic drug evaluation of osimertinib for the treatment of non-small cell lung cancer

Introduction: First- and second-generation epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs), such as gefitinib, erlotinib, icotinib, and afatinib are the standard-of-care for first-line therapy of non-small-cell lung cancer (NSCLC) harboring activating EGFR mutations. Unfortunately, after initial activity of an average 9–13 months, disease progression has been reported in the majority of patients. In about 50% of cases the progression is due to the onset of the T790M mutation in exon 20 of the EGFR gene. Third-generation EGFR-TKIs targeting this mutation were investigated, with osimertinib the only reaching clinical practice.

Areas covered: A structured search of bibliographic databases for peer-reviewed research literature and of main meetings using a focused review question addressing osimertinib, was undertaken.

Expert opinion: Osimertinib is the standard-of-care for EGFR-mutated patients progressing to first-line EGFR-TKIs due to the acquired EGFR T790M mutation. Results from the head-to-head first-line trial comparing osimertinib versus gefitinib or erlotinib in activating EGFR mutations might change the front-line approach. Osimertinib in combination regimens, such as immunotherapy, and in adjuvant setting are ongoing. Thus, the strategic approach for the management of EGFR-mutated NSCLC patients will change further in the next few years.     

Rociletinib,a third generation EGFR tyrosine kinase inhibitor: current data and future directions

Introduction: Major advances have been made since the discovery of driver mutations and their targeted therapies, especially in the treatment of patients with epidermal growth factor receptor (EGFR) mutations. Despite their initial efficacy in the majority of the patients with such driver mutations, all targeted therapies are limited by the eventual development of resistance mechanisms.

Areas Covered: EGFR T790M mutation is a common resistance mechanism after treatment with first or second generation EGFR tyrosine kinase inhibitors (TKI). Rociletinib is one of the third generation EGFR TKIs with activity against T790M and activating EGFR mutations while sparing the wild-type EGFR. In this review, we discuss the current understanding and available data on rociletinib, including the side effects associated with the medication. We will also review the BEAMing plasma test to detect T790M mutation without the need for repeat biopsy. Lastly, we review the potential resistance mechanisms after progression on rociletinib, and future directions.

Expert Opinion: It is important to note that there are other 3^rd generation EGFR TKIs with activity against T790M already approved by the US FDA (osimertinib) and many others in development. Future research will focus on figuring out which patients can benefit the most from a particular medication with minimal side effects, and further resistance mechanisms after rociletinib.     

Osimertinib for the treatment of non-small cell lung cancer

Introduction: The T790 M mutation of the epidermal growth factor receptor (EGFR) gene is the most common mechanism underlying resistance to first- or second-generation EGFR tyrosine kinase inhibitors (TKIs) in patients with non-small cell lung cancer (NSCLC). Osimertinib, a third-generation EGFR TKI, shows robust clinical efficacy in patients with T790 M-mutated lung cancer.

Areas covered: We analyzed and reviewed clinical data for which patients who experienced acquired resistance to first- or second-generation EGFR TKIs. In addition, we briefly reviewed the potential role of osimertinib as a first-line therapy.

Expert opinion: Osimertinib was recently licensed for use in NSCLC patients with acquired resistance to other EGFR TKIs due to a T790 M mutation. However, unresolved issues surrounding the optimal application of osimertinib remain, specifically the development of a plasma-based mutation test to overcome the difficulty of repeat biopsy, the efficacy of osimertinib for brain or leptomeningeal metastases, the development of resistance to osimertinib, and the use of osimertinib therapy as a first-line treatment. Many ongoing studies are currently exploring these issues.     

Recent understanding of the molecular mechanisms for the efficacy and resistance of EGF receptor-specific tyrosine kinase inhibitors in non-small cell lung cancer

Introduction: The epidermal growth factor receptor (EGFR) and its family members are involved in many aspects of tumor biological processes. Aberrant activation of the EGFR tyrosine kinase by mutations or protein overexpression is observed in various types of human cancer, including lung cancer. EGFR tyrosine kinase inhibitors (EGFR-TKIs), such as gefitinib and erlotinib, are highly effective in lung cancer patients who harbor active mutations in the EGFR gene. However, patients who are initially sensitive to EGFR-TKIs eventually relapse within few years.

Areas covered: Non-small cell lung cancer (NSCLC) is the most common type of lung cancer and is associated with a high frequency of EGFR mutations. This review describes the EGFR mutations that determine the sensitivity to EGFR-TKIs and the current understanding of the molecular mechanisms of acquired resistance to EGFR-TKIs in NSCLC. Furthermore, the authors describe recent strategies developed to overcome acquired resistance using second-generation EGFR-TKIs and combination therapies with several molecular-targeting drugs.

Expert opinion: Although recent findings have contributed to our understanding of the mechanism of acquired resistance and helped the development of novel strategies to overcome such resistance, the underlying mechanisms are complex and additional research is necessary to develop effective therapeutic strategies for individual patients with lung cancer.     

Real-world use of osimertinib in non–small cell lung cancer: ASTRIS study Korean subgroup analysis

Abstract

Objective: ASTRIS is a large real-world, open-label, multinational clinical study of osimertinib in patients with epidermal growth factor receptor (EGFR) T790M mutation-positive advanced non-small cell lung cancer (NSCLC) who have previously received a tyrosine kinase inhibitor (TKI). We report data from the Korean ASTRIS subgroup.

Methods: Adult patients with locally advanced or metastatic NSCLC with a confirmed T790M mutation, WHO performance status of 0–2 and prior EGFR-TKI therapy, received osimertinib 80?mg once daily. Efficacy outcomes were overall survival (OS), investigator-assessed response rate (RR) and progression-free survival (PFS), and time to treatment discontinuation (TTD).

Results: At data cut-off (20 October 2017), 466 Korean patients were enrolled. Baseline EGFR molecular testing was mainly performed on biopsied tissue (75.1%). Baseline mutations co-occurring with T790M included exon 19 deletions (60.7%) and L858R (32.8%). 1-year OS was 82.7% (OS data not matured at data cut-off). Overall, RR was 71.0%, median PFS was 12.4?months and median TTD was 15.0?months. In patients with/without CNS metastases, RR was 68.0% and 79.6%, respectively; median PFS, 10.8 and 11.0?months, respectively; and median TTD, 11.2 and 14.7?months, respectively. Overall, 31.1% of patients experienced ≥1 adverse event (AE), leading to dose modification (12.0%), discontinuation (5.2%) or death (2.8%). Serious AEs (24.9%) included pulmonary embolism (1.7%), pleural effusion (1.7%), and pneumonia (1.5%).

Conclusion: In this real-world subgroup analysis of Korean patients in the ASTRIS study, osimertinib demonstrated comparable clinical efficacy to that attained in the global ASTRIS study and other clinical trials, with no new safety concerns.     

T790M突变与表皮生长因子受体酪氨酸激酶抑制剂继发耐药的相关性

目的:探讨表皮生长因子本酪氨酸激酶抑制剂(EGFR-TKIs)治疗晚期非小细胞肺癌继发耐药的机制。方法:用富集突变PCR(Mutation–enriched PCR)分析46例初治有效且维持≥6个月的晚期非小细胞肺癌患者的外周血和石蜡包埋组织标本的EGFR20外显子T790M突变,分析其与病理特征、疗效、无疾病进展生存时间(PFS)的相关性。结果:46例患者进展期外周血标本中,T790M突变率为39.13%(18/46例),明显高于治疗前标本中5.88%(2/34例)。T790M突变阳性者中位PFS为16.4个月(95%CI:10.83～17.47),野生型患者中位PFS10.2个月(95%CI:10.2～13.47)(P=0.6139)。结论:研究表明T790M突变与EGFR-TKIs继发耐药相关,在非小细胞肺癌患者中存在动态变化,与疗效和生存可能有一定相关性。     

EGFR突变肺癌脑膜转移奥希替尼加量治疗1例

非小细胞肺癌（NSCLC）脑膜转移患者的生存期短,治疗方法有限。奥希替尼是第三代表皮生长因子受体酪氨酸激酶抑制剂（EGFR-TKI）,可高效抑制EGFR敏感突变和EGFR T790M耐药突变,同时对EGFR突变的NSCLC软脑膜转移患者也有很好的疗效。本文报道1例奥希替尼加量至160 mg·d^-1治疗EGFR突变肺腺癌脑膜转移,为临床治疗NSCLC难治性软脑膜转移提供参考。     

奥希替尼治疗EGFR突变的晚期非小细胞肺癌疗效与安全性的Meta分析

目的 系统评价奥希替尼治疗非小细胞肺癌(NSCLC)的疗效和安全性.方法 计算机检索The Cochrane Library、EMbase、PubMed、中国知网、维普网、万方数据建库至2019年12月31日,查找奥希替尼治疗NSCLC的随机对照试验(RCTs),并进行质量评价和资料提取,用Stata 12.0进行Me...     

Targeting epidermal growth factor receptor: Central signaling kinase in lung cancer

Non-small cell lung cancer (NSCLC) is the leading cause of cancer mortality worldwide. Platinum-based doublets remain the current standard therapy for advanced NSCLC. However, overall survival (OS) has reached a plateau, even with the improvement in these regimens. Advances in the knowledge of molecular mechanisms of carcinogenesis have prompted the development of many novel molecular-targeted agents including the epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs). Results of the recent phase III IPASS trial showed that the EGFR-TKI gefitinib has a superior progression-free survival (PFS) to the most commonly used platinum-based doublet carboplatin-paclitaxel as the first-line chemotherapy for pulmonary lung adenocarcinoma among nonsmokers in East Asia. This trial also demonstrated that the presence of EGFR mutation is the best predictor of gefitinib treatment compared with the other biomarkers including EGFR gene copy number. Despite the therapeutic benefit of EGFR-TKIs in NSCLC, most patients eventually develop resistance to these drugs. A secondary mutation of EGFR (T790M) and amplification of MET account for 70% of all cases of acquired resistance to EGFR-TKIs. This review summarizes the significance of EGFR mutations and the mechanisms of resistance to EGFR-TKIs in NSCLC, both of which are critical for patient selection to extend survival as well as to overcome resistance in NSCLC patients treated with EGFR-TKIs.     

Targeting the EGFR T790M mutation in non-small-cell lung cancer

Introduction: The presence of activating mutations of the epidermal growth factor receptor (EGFR) is predictive of response to first- and second-generation tyrosine kinase inhibitors (TKIs) in patients with advanced non-small-cell lung cancer (NSCLC). However, patients that initially respond to these drugs inexorably become resistant. The T790M mutation in the exon 20 of the EGFR is the main mechanism of resistance to EGFR TKIs occurring in over 50% of the cases. Third generation EGFR TKIs have been shown to be active in patients who progressed after TKI treatment and carry the T790M mutation.

Areas covered: This review is focused on the implications of tumor heterogeneity for targeting the T790M in patients with NSCLC.

Expert opinion: Pre-clinical and clinical data suggest that the T790M is heterogeneously expressed in tumors that become resistant to first- and second-generation EGFR TKIs. These findings have important implications for the molecular diagnostic of the T790M mutation. Indeed, the analysis of both the circulating free tumor DNA (ctDNA) isolated from plasma and the tumor tissue might provide complimentary information to identify patients carrying the T790M mutation. However, further studies are needed to better understand the influence of tumor heterogeneity on the activity of drugs targeting the T790M.     

Pharmacotherapy targeting the EGFR oncogene in NSCLC

Introduction: The EGFR plays a central role in regulating cancer cell growth and survival, representing an attractive therapeutic target in NSCLC.

Areas covered: For the purpose of this review article, data from Phase II and III trials with anti-EGFR agents, including EGFR-tyrosine kinase inhibitors (TKIs) and mAbs, were collected and analysed.

Expert opinion: Eight large Phase III trials demonstrated that EGFR-TKIs are the best option we can offer today as front-line therapy exclusively in EGFR mutant NSCLC. In patients with EGFR wild type or unknown lung cancer, platinum-based chemotherapy remains the standard of care, with no consistent benefit produced by the addition of an anti-EGFR treatment. In pretreated NSCLC, EGFR-TKIs are considered more effective than standard monotherapy with cytotoxics in presence of classical EGFR mutations, whereas in the EGFR wild-type population, a similar efficacy with docetaxel or pemetrexed in terms of survival has been demonstrated. New agents targeting EGFR are under investigation, particularly in individuals with squamous cell histology and those with acquired resistance to EGFR-TKIs.     

Targeting DNA-PK overcomes acquired resistance to third-generation EGFR-TKI osimertinib in non-small-cell lung cancer

The third-generation of epidermal growth factor receptor(EGFR)tyrosine kinase inhibitors(TKIs),represented by osimertinib,has achieved remarkable clinical outcomes in the treatment of non-small-cell lung cancer(NSCLC)with EGFR mutation.However,resistance eventually emerges in most patients and the underlying molecular mechanisms remain to be fully understood.In this study,we generated an osimertinib-acquired resistant lung cancer model from a NSCLC cell line H1975 harboring EGFR L858R and T790M mutations.We found that the capacity of DNA damage repair was compromised in the osimertinib resistant cells,evidenced by increased levels ofγH2AX and higher intensity of the comet tail after withdrawal from cisplatin.Pharmacological inhibiting the activity or genetic knockdown the expression of DNA-PK,a key kinase in DNA damage response(DDR),sensitized the resistant cells to osimertinib.Combination of osimertinib with the DNA-PK inhibitor,PI-103,or NU7441,synergistically suppressed the proliferation of the resistant cells.Mechanistically,we revealed that DNA-PK inhibitor in combination with osimertinib resulted in prolonged DNA damage and cell cycle arrest.These findings shed new light on the mechanisms of osimertinib resistance in the aspect of DNA repair,and provide a rationale for targeting DNA-PK as a therapeutic strategy to overcome osimertinib-acquired resistance in NSCLC.     

第三代EGFR-TKI奥希替尼临床研究进展

奥希替尼是第三代表皮生长因子受体酪氨酸激酶抑制剂（EGFR-TKI）,被批准用于治疗EGFR T790M突变阳性的局部晚期或转移性非小细胞肺癌（NSCLC）的抗肿瘤药物。其疗效显著,耐受性较好,副作用较第一、二代EGFR-TKI更易被接受。对已接受其他EGFR-TKI治疗且出现耐药的患者,奥希替尼可为该类患者带来新的选择。2017年3月22日国家食品药品监督管理总局（CFDA）加速批准了阿斯利康公司的甲磺酸奥希替尼片的进口申请。现就奥希替尼的作用机制、上市情况、临床实验、药动学、耐受性和安全性进行综述,为临床应用提供参考。     

Emerging drugs for EGFR-mutated non-small cell lung cancer

Introduction: Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) represent the standard of care for patients with metastatic non-small-cell lung cancer (NSCLC) harboring sensitizing EGFR mutations. However, these agents are associated with inevitable treatment resistance. Newer generations of TKIs are under development that may prevent or overcome resistance and enhance intracranial activity.

Areas covered: In this review, we will discuss newer generations of EGFR TKIs for EGFR-mutated NSCLC. We will also address resistance mutations and escape pathways associated with these agents such as secondary mutations, downstream signaling, bypass pathways, phenotypic transformation, anti-apoptotic signaling, immune evasion, and angiogenesis. Furthermore, this article encompasses emerging data from combination trials with next-generation TKIs that are being pursued to delay or prevent the occurrence of resistance.

Expert opinion: The promise and challenge of precision oncology is encapsulated in the treatment of EGFR-mutated NSCLC with TKIs. Third generation TKIs have shown superior efficacy in the front-line setting and have become standard of care. A better understanding of mechanisms of treatment failure and disease relapse will be required to develop novel therapeutic strategies to further improve patient outcomes in the future.     

奥希替尼获得性耐药的研究进展

奥希替尼作为第三代表皮生长因子受体酪氨酸激酶抑制剂,对表皮生长因子受体(EGFR)T790M突变型肺腺癌有显著疗效。随着临床研究的深入,奥希替尼的耐药逐渐出现。如何应对奥希替尼耐药已成为临床工作者必须关注的问题。本文就奥希替尼获得性耐药机制及应对措施的最新研究进展进行综述。     

Evolution in the treatment landscape of non-small cell lung cancer with ALK gene alterations: from the first- to third-generation of ALK inhibitors

ABSTRACT

Introduction: The medical treatment of non-small cell lung cancer (NSCLC) has radically changed over the last 10 years thanks to new molecular-targeted drugs able to act on biological mechanisms involved in tumor development. One such mechanism is the aberrant anaplastic lymphoma kinase (ALK) activation: patients with ALK-driven NSCLC benefit from treatments that selectively inhibit its pathogenetic mechanism.

Areas covered: The first-generation ALK inhibitor is crizotinib, initially used in Europe as second-line treatment for ALK-positive metastatic NSCLC patients, then approved as the standard first-line (already approved in the USA as front-line therapy). However, most patients eventually experience disease progression due to the emergence of secondary resistance, partly linked to ALK-dependent mechanisms, hence the development of second- and third-generation ALK inhibitors: ceritinib, alectinib, and brigatinib are approved for ALK-positive NSCLC, lorlatinib is currently being evaluated while others are under development.

Expert opinion: Despite the considerable responses to these new inhibitors, however, resistance mechanisms are described. Thus, while the therapeutic scenario of NSCLC has been soon revolutionized introducing next-generation ALK inhibitors in the first-line setting, future research should identify combined therapies or new generation drugs overcoming resistance in pretreated patients.     

Recent understanding of the molecular mechanisms for the efficacy and resistance of EGF receptor-specific tyrosine kinase inhibitors in non-small cell lung cancer

INTRODUCTION: The epidermal growth factor receptor (EGFR) and its family members are involved in many aspects of tumor biological processes. Aberrant activation of the EGFR tyrosine kinase by mutations or protein overexpression is observed in various types of human cancer, including lung cancer. EGFR tyrosine kinase inhibitors (EGFR-TKIs), such as gefitinib and erlotinib, are highly effective in lung cancer patients who harbor active mutations in the EGFR gene. However, patients who are initially sensitive to EGFR-TKIs eventually relapse within few years. AREAS COVERED: Non-small cell lung cancer (NSCLC) is the most common type of lung cancer and is associated with a high frequency of EGFR mutations. This review describes the EGFR mutations that determine the sensitivity to EGFR-TKIs and the current understanding of the molecular mechanisms of acquired resistance to EGFR-TKIs in NSCLC. Furthermore, the authors describe recent strategies developed to overcome acquired resistance using second-generation EGFR-TKIs and combination therapies with several molecular-targeting drugs. EXPERT OPINION: Although recent findings have contributed to our understanding of the mechanism of acquired resistance and helped the development of novel strategies to overcome such resistance, the underlying mechanisms are complex and additional research is necessary to develop effective therapeutic strategies for individual patients with lung cancer.     

第三代EGFR-TKIs在晚期非小细胞肺癌中的遴选量化评估

目的:通过对奥希替尼、阿美替尼和伏美替尼进行量化评估,以期为医院遴选第三代表皮生长因子受体酪氨酸激酶抑制剂(epidermal growth factor receptor tyrosine kinase inhibitors,EGFR-TKIs)提供依据。方法:从有效性、药学特性、安全性、经济性和其他属性5个方面对第三代EGFR-TKIs进行评估。结果:奥希替尼、阿美替尼和伏美替尼的遴选量化评估最终分值分别为80.6,66.2,65.9分。结论:根据评分结果,医疗机构在引入第三代EGFR-TKIs治疗晚期非小细胞肺癌时,建议遴选顺序为奥希替尼＞阿美替尼＞伏美替尼,在药品调整时可酌情选择总分较低的药品调出。     

阿美替尼治疗非小细胞肺癌的研究进展

肺癌是全球癌症相关死亡的最常见原因,其中85%为非小细胞肺癌(non-small-cell lung cancer,NSCLC),表皮生长因子受体(epidermal growth factor receptor,EGFR)是治疗晚期NSCLC最重要的靶点之一。第一、二代EGFR酪氨酸激酶抑制剂(EGFR-tyrosine kinase inhibitor,EGFR-TKI)一直是晚期EGFR突变NSCLC患者的标准治疗方法,但获得性耐药几乎不可避免,主要耐药原因为T790M突变。阿美替尼是中国首个自主研发的第三代EGFR-TKI,对包括L858R和19号外显子缺失在内的EGFR敏感突变,以及T790M耐药突变均具有活性,同时保留野生型EGFR,克服了第一、二代EGFR-TKI的耐药性和选择性问题,其临床前和临床研究均显示出良好的有效性与安全性,为我国NSCLC患者提供了新的用药选择。本综述对阿美替尼的结构、作用机制、临床前研究、药动学,在NSCLC治疗中的临床疗效、安全性,以及与其他第三代EGFR-TKI的比较进行了总结,为该药的临床使用及未来的探索研究提供参考。     

Identifying nonsmall‐cell lung tumours bearing the T790M EGFR TKI resistance mutation using PET imaging

Specific mutations significantly affect response to epidermal growth factor tyrosine kinase inhibitor (EGFR‐TKI) treatment in lung cancer patients. Identifying patients with these mutations remains a major clinical challenge. EGFR T790M mutation, which conveys resistance to in the present study, [¹⁸F]FEWZ was assessed in vitro to determine efficacy relative to the starting compound and in vivo to measure the biodistribution and specificity of binding to EGFR wild‐type, L858R and T790M bearing tumours. [¹⁸F]FEWZ is the first evidence of a radiolabeled third generation anilinopyrimidine‐derived tyrosine kinase inhibitor targeting T790M mutation bearing tumours in vivo.