Osimertinib for pretreated EGFR Thr790Met-positive advanced non-small-cell lung cancer (AURA2): a multicentre, open-label, single-arm, phase 2 study

Integrating Osimertinib in Clinical Practice for Non-Small Cell Lung Cancer Treatment

Treatment of non-small cell lung cancer (NSCLC) is evolving with the use of precision medicine for patients with sensitizing epidermal growth factor receptor (EGFR) mutation. First- and second-generation EGFR tyrosine kinase inhibitors (TKIs) remained the standard of care for patients with EGFR-mutated advanced NSCLC for about a decade. However, treatment resistance eventually develops for most patients who experience initial response to these agents. The most commonly acquired resistance mechanism is the T790M gatekeeper mutation. Poor drug penetration leading to central nervous system (CNS) relapse and dose-limiting toxicities are other concerns. The third-generation EGFR-TKI osimertinib, initially approved as the second-line treatment for patients with T790-mutant NSCLC, demonstrated survival benefits in TKI-naïve EGFR-mutated patients, especially in patients with CNS metastasis. The FLAURA study has shown statistically significant progression-free survival benefit and prolongation of all post-progression outcome endpoints, time to first subsequent therapy, second subsequent therapy, and second progression on subsequent treatment, along with acceptable toxicity and better quality of life outcomes. These data favor osimertinib in the first-line setting for EGFR-mutated NSCLC. This is an important milestone since sequencing the TKI therapy based on accurate prediction of T790M is clinically challenging. In countries like India, T790M testing is not routinely conducted and two-thirds of patients with NSCLC do not receive any second-line therapy. Osimertinib can be administered pragmatically as a first-line therapy. Mature overall survival data from the FLAURA study will be important and could help define the optimal personalized treatment for patients with advanced NSCLC.Funding: AstraZeneca Pharma India Ltd.

Significant benefits of osimertinib in treating acquired resistance to first-generation EGFR-TKIs in lung squamous cell cancer: A case report

BACKGROUND

Lung squamous cell cancer (LSCC) rarely harbors epidermal growth factor receptor (EGFR) mutations, even much rarer for acquired T790M mutation. Although clinical trials of AURA series illustrated that non-small cell lung cancer (NSCLC) with EGFR T790M mutation can benefit from osimertinib, only five LSCC patients were enrolled in total; moreover, the efficacy for LSCC was not shown in the results. Therefore, the response of LSCC to osimertinib is still unclear to date.

CASE SUMMARY

We report an LSCC case with T790M-related acquired resistance after treatments with first-generation EGFR-tyrosine kinase inhibitors (EGFR-TKIs) and benefited from osimertinib significantly. A 63-year-old Chinese man was diagnosed with stage IV (cT2N2M1b) LSCC harboring an EGFR exon 19-deletion mutation. Following disease progression after gefitinib and multi-line chemotherapy, re-biopsy was conducted. Molecular testing of EGFR by amplification refractory mutation system-polymerase chain reaction detected the exon 19-deletion without T790M mutation. Therefore, the patient was given erlotinib, but progression developed only 3 mo later. Then the frozen re-biopsy tissue was tested by next-generation sequencing (NGS), which detected an EGFR T790M mutation. However, he was very weak with symptoms of dysphagia and cachexia. Fortunately, osimertinib was started, leading to alleviation from the symptoms. Four months later, normal deglutition was restored and partial response was achieved. Finally, the patient achieved an overall survival time period of 29 mo.

CONCLUSION

Our findings highlight that EGFR T790M mutation may also be an important acquired drug resistance mechanism for LSCC and offer direct evidence of the efficacy of osimertinib in LSCC with T790M mutation. NGS and better preservation conditions may contribute to higher sensitivity of EGFR T790M detection.

Making the first move in EGFR-driven or ALK-driven NSCLC: first-generation or next-generation TKI?

The traditional approach to the treatment of patients with advanced-stage non-small-cell lung carcinoma (NSCLC) harbouring ALK rearrangements or EGFR mutations has been the sequential administration of therapies (sequential treatment approach), in which patients first receive first-generation tyrosine-kinase inhibitors (TKIs), which are eventually replaced by next-generation TKIs and/or chemotherapy upon disease progression, in a decision optionally guided by tumour molecular profiling. In the past few years, this strategy has been challenged by clinical evidence showing improved progression-free survival, improved intracranial disease control and a generally favourable toxicity profile when next-generation EGFR and ALK TKIs are used in the first-line setting. In this Review, we describe the existing preclinical and clinical evidence supporting both treatment strategies - the 'historical' sequential treatment strategy and the use of next-generation TKIs - as frontline therapies and discuss the suitability of both strategies for patients with EGFR-driven or ALK-driven NSCLC.

Single and Dual Targeting of Mutant EGFR with an Allosteric Inhibitor

Allosteric kinase inhibitors offer a potentially complementary therapeutic strategy to ATP-competitive kinase inhibitors due to their distinct sites of target binding. In this study, we identify and study a mutant-selective EGFR allosteric inhibitor, JBJ-04-125-02, which as a single agent can inhibit cell proliferation and EGFR^{L858R/T790M/C797S} signaling in vitro and in vivo. However, increased EGFR dimer formation limits treatment efficacy and leads to drug resistance. Remarkably, osimertinib, an ATP-competitive covalent EGFR inhibitor, uniquely and significantly enhances the binding of JBJ-04-125-02 for mutant EGFR. The combination of osimertinib and JBJ-04-125-02 results in an increase in apoptosis, a more effective inhibition of cellular growth, and an increased efficacy in vitro and in vivo compared with either single agent alone. Collectively, our findings suggest that the combination of a covalent mutant-selective ATP-competitive inhibitor and an allosteric EGFR inhibitor may be an effective therapeutic approach for patients with EGFR-mutant lung cancer. SIGNIFICANCE: The clinical efficacy of EGFR tyrosine kinase inhibitors (TKI) in EGFR-mutant lung cancer is limited by acquired drug resistance, thus highlighting the need for alternative strategies to inhibit EGFR. Here, we identify a mutant EGFR allosteric inhibitor that is effective as a single agent and in combination with the EGFR TKI osimertinib.This article is highlighted in the In This Issue feature, p. 813.

Determination of osimertinib in human plasma, urine and cerebrospinal fluid

Aim: Osimertinib (Tagrisso, AZD9291) has been approved for the treatment of patients with metastatic EGFRm T790M non-small-cell lung cancer. Results: Rapid and sensitive LC–MC/MS methods were developed for osimertinib and its metabolites, AZ13597550 and AZ13575104, in human plasma (low- and high-range), urine and cerebrospinal fluid. We discuss the challenges of these multi-analyte and multiple matrix assays. The methods have been successfully validated and used for the analysis of over 20,000 clinical samples, with successful incurred sample reproducibility. Conclusion: The assays have been shown to be selective, accurate and robust, providing high-throughput analysis during the clinical development of osimertinib.

Pharmacokinetic Study of Osimertinib in Cancer Patients with Mild or Moderate Hepatic Impairment

Osimertinib, an epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI), undergoes significant hepatic elimination. In this phase 1 study, we assessed the effects of mild and moderate hepatic impairment on the pharmacokinetics (PK) of osimertinib in patients with malignant solid tumors. In part A, patients with normal hepatic function, mild hepatic impairment, and moderate hepatic impairment, according to the Child-Pugh classification, received a single 80 mg oral dose of osimertinib. Standard PK measures were assessed. In part B, patients could continue osimertinib treatment if deemed clinically appropriate. We compared these study results with a population PK analysis including other osimertinib clinical studies. Geometric mean osimertinib plasma concentrations were lower in patients with mild (n = 7) or moderate hepatic impairment (n = 5) versus normal hepatic function (n = 10): C max was reduced to 51% and 61%, respectively; area under the curve was reduced to 63% and 68%, respectively. PK results for the metabolites were similar. No apparent differences in the safety profile were found between patients with normal hepatic function and patients with mild or moderate hepatic impairment. Comparison of these study results with National Cancer Institute-Organ Dysfunction Working Group criteria from population PK analysis showed osimertinib exposure was not affected by hepatic impairment. No dose adjustment is required for osimertinib when treating patients with mild or moderate hepatic impairment. No apparent differences in the safety of osimertinib were found between patients with normal hepatic function and mild or moderate hepatic impairment.

Development of an LC–MS/MS-based method for quantitation of osimertinib in human plasma and cerebrospinal fluid

Aim: The transitivity of osimertinib to cerebrospinal fluid (CSF) is of clinical concern. A quantitative LC–MS/MS method for the determination of osimertinib in human plasma and CSF was developed to evaluate its transitivity. Results: The calibration range was 40–1000 nM in plasma and 0.8–100 nM in CSF. Accuracy and precision were within 15%. Osimertinib in the CSF but not in plasma strongly adsorbed onto the storage container. The mean adsorbed loss of osimertinib was 45.5% in CSF. Nonspecific binding in CSF was decreased by protein addition (mean loss = 5.8%). Conclusion: A robust validated method was developed for the quantification of osimertinib in human plasma and CSF.

Acquired BRAF Rearrangements Induce Secondary Resistance to EGFR therapy in EGFR-Mutated Lung Cancers

INTRODUCTION

Multiple genetic mechanisms have been identified in EGFR-mutant lung cancers as mediators of acquired resistance (AR) to EGFR tyrosine kinase inhibitors (TKIs), but many cases still lack a known mechanism.

METHODS

To identify novel mechanisms of AR, we performed targeted large panel sequencing of samples from 374 consecutive patients with metastatic EGFR-mutant lung cancer, including 174 post-TKI samples, of which 38 also had a matched pre-TKI sample. Alterations hypothesized to confer AR were introduced into drug-sensitive EGFR-mutant lung cancer cell lines (H1975, HCC827, and PC9) by using clustered regularly interspaced short palindromic repeats/Cas9 genome editing. MSK-LX138cl, a cell line with EGFR exon 19 deletion (ex19del) and praja ring finger ubiquitin ligase 2 gene (PJA2)/BRAF fusion, was generated from an EGFR TKI-resistant patient sample.

RESULTS

We identified four patients (2.3%) with a BRAF fusion (three with acylglycerol kinase gene (AGK)/BRAF and one with PJA2/BRAF) in samples obtained at AR to EGFR TKI therapy (two posterlotinib samples and two posterlotinib and postosimertinib samples). Pre-TKI samples were available for two of four patients and both were negative for BRAF fusion. Induction of AGK/BRAF fusion in H1975 (L858R + T790M), PC9 (ex19del) and HCC827 (ex19del) cells increased phosphorylation of BRAF, MEK1/2, ERK1/2, and signal transducer and activator of transcription 3 and conferred resistance to growth inhibition by osimertinib. MEK inhibition with trametinib synergized with osimertinib to block growth. Alternately, a pan-RAF inhibitor as a single agent blocked growth of all cell lines with mutant EGFR and BRAF fusion.

CONCLUSION

BRAF fusion is a mechanism of AR to EGFR TKI therapy in approximately 2% of patients. Combined inhibition of EGFR and MEK (with osimertinib and trametinib) or BRAF (with a pan-RAF inhibitor) are potential therapeutic strategies that should be explored.

Emerging therapies for non-small cell lung cancer

Recent advances in the field of novel anticancer agents prolong patients' survival and show a promising future. Tyrosine kinase inhibitors and immunotherapy for lung cancer are the two major areas undergoing rapid development. Although increasing novel anticancer agents were innovated, how to translate and optimize these novel agents into clinical practice remains to be explored. Besides, toxicities and availability of these drugs in specific regions should also be considered during clinical determination. Herein, we summarize emerging agents including tyrosine kinase inhibitors, checkpoint inhibitors, and other potential immunotherapy such as chimeric antigen receptor T cell for non-small cell lung cancer attempting to provide insights and perspectives of the future in anticancer treatment.

Genetic Profiling of Non-Small Cell Lung Cancer at Development of Resistance to First- or Second-Generation EGFR-TKIs by CAPP-Seq Analysis of Circulating Tumor DNA

Patients with non-small cell lung cancer (NSCLC) treated with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) eventually acquire resistance to these drugs. The identification of various resistance mechanisms for determination of subsequent treatment for these patients will require a method for simultaneous detection of multiple genetic alterations with high sensitivity. We performed cancer personalized profiling by deep sequencing (CAPP-Seq) with circulating tumor DNA obtained from patients with NSCLC who acquired resistance to first- or second-generation EGFR-TKIs. Plasma samples from 27 patients were analyzed, and 24 samples underwent CAPP-Seq successfully. Original activating EGFR mutations were detected in 23 patients, with the remaining patient showing MET amplification. With regard to known mechanisms of EGFR-TKI resistance, the T790M mutation of EGFR was detected in 17 of the 24 patients, MET amplification in 9 patients (6 of whom also harbored T790M), ERBB2 amplification in 2 patients (1 of whom also harbored T790M), and EGFR amplification in 4 patients (all of whom harbored T790M). Our results thus show that CAPP-Seq is applicable to clinical samples for the identification of multiple somatic mutations in circulating tumor DNA obtained from patients with NSCLC at the time of disease progression during treatment with first- or second-generation EGFR-TKIs. Patients positive for the T790M mutation of EGFR were also found to constitute a molecularly heterogeneous population. KEY POINTS: CAPP-Seq is applicable to clinical samples for the identification of multiple somatic mutations.The T790M mutation of EGFR is associated with amplification of MET, ERBB2, or EGFR in NSCLC patients resistant to EGFR-TKIs.T790M-positive patients are molecularly heterogeneous, and genetic alterations coexisting with T790M may differ between patients treated with first-generation or second-generation EGFR-TKIs.

Clinical Validation of a Cell-Free DNA Gene Panel

The use of liquid biopsies to identify driver mutations in patients with solid tumors holds great promise for performing targeted therapy selection, monitoring disease progression, and detecting treatment resistance mechanisms. We describe herein the development and clinical validation of a 28-gene cell-free DNA panel that targets the most common genetic alterations in solid tumors. Bioinformatic and variant filtering solutions were developed to improve test sensitivity and specificity. The panel and these tools were used to analyze commercially available controls, allowing establishment of a limit of detection allele fraction cutoff of 0.25%, with 100% (95% CI, 81.5%-100%) specificity and 89.8% (95% CI, 81.0%-94.9%) sensitivity. In addition, we analyzed a total of 163 blood samples from patients with metastatic cancer (n = 123) and demonstrated a >90% sensitivity for detecting previously identified expected mutations. Longitudinal monitoring of patients revealed a strong correlation of variant allele frequency changes and clinical outcome. Additional clinically relevant information included identification of resistance mutations in patients receiving targeted treatment and detection of complex patterns of mutational heterogeneity. Achieving lower limits of detection will require additional improvements to molecular barcoding; however, these data strongly support clinical implementation of cell-free DNA panels in advanced cancer patients.

Impact of single nucleotide polymorphisms on the efficacy and toxicity of EGFR tyrosine kinase inhibitors in advanced non-small cell lung cancer patients

EGFR tyrosine kinase inhibitors (EGFR-TKIs) are the treatment of choice for advanced-stage (IIIB-IV) NSCLC patients with mutations in EGFR. However, EGFR-TKIs clinical outcomes vary from person to person and these inter-individual differences may be due to genetic factors such as single nucleotide polymorphisms (SNPs). SNPs in genes involved in EGFR-TKIs pharmacodynamics, metabolism and mechanism of action have been demonstrated to be associated with response, survival and toxicity in advanced NSCLC patients treated with EGFR-TKIs. Here we review the influence of gene polymorphisms in the EGFR pathway on clinical outcome and toxicity to EGFR-TKIs in advanced NSCLC patients. The EGFR-216 polymorphism has reported a strong association between response and/or survival to EGFR-TKIs in Caucasian population. Similarly, the effect of EGFR-CA repeats polymorphisms on survival of advanced NSCLC patients treated with EGFR-TKIs have been confirmed both in Caucasian and Asian population. The influence on toxicity of the -216, -191, CA repeats, Arg497Lys and Asp994Asp polymorphisms in EGFR have also been confirmed. Polymorphisms in AKT (rs1130214 and rs1130233) and SMAD3 (rs6494633, rs11071938 and rs11632964) have been associated with survival in advanced NSCLC patients treated with EGFR-TKIs. However, data come from a limited number of studies and need to be confirmed. Finally, polymorphisms in genes coding proteins of the membrane transporters and cytochrome P450 enzymes have been less extensively investigated. There are few studies with small samples, which complicated the generalization of their role in EGFR-TKIs treatment.

CNS response to osimertinib in patients with T790M-positive advanced NSCLC: pooled data from two phase II trials

Background

Central nervous system (CNS) metastases are common in patients with non-small-cell lung cancer (NSCLC). Osimertinib has shown systemic efficacy in patients with CNS metastases, and early clinical evidence shows efficacy in the CNS. To evaluate osimertinib activity further, we present a pre-specified subgroup analysis of CNS response using pooled data from two phase II studies: AURA extension (NCT01802632) and AURA2 (NCT02094261).

Patients and methods

Patients with T790M-positive advanced NSCLC, who had progressed following prior epidermal growth factor receptor-tyrosine kinase inhibitor treatment, received osimertinib 80 mg od (n = 411). Patients with stable, asymptomatic CNS metastases were eligible for enrolment; prior CNS treatment was allowed. Patients with ≥1 measurable CNS lesion (per RECIST 1.1) on baseline brain scan by blinded independent central neuroradiology review (BICR) were included in the evaluable for CNS response set (cEFR). The primary outcome for this CNS analysis was CNS objective response rate (ORR) by BICR; secondary outcomes included CNS duration of response, disease control rate (DCR) and progression-free survival (PFS).

Results

Of 128 patients with CNS metastases on baseline brain scans, 50 were included in the cEFR. Confirmed CNS ORR and DCR were 54% [27/50; 95% confidence interval (CI) 39-68] and 92% (46/50; 95% CI 81-98), respectively. CNS response was observed regardless of prior radiotherapy to the brain. Median CNS duration of response (22% maturity) was not reached (range, 1-15 months); at 9 months, 75% (95% CI 53-88) of patients were estimated to remain in response. Median follow-up for CNS PFS was 11 months; median CNS PFS was not reached (95% CI, 7, not calculable). The safety profile observed in the cEFR was consistent with the overall patient population.

Conclusions

Osimertinib demonstrated clinically meaningful efficacy against CNS metastases, with a high DCR, encouraging ORR, and safety profile consistent with that reported previously.

ClinicalTrials.gov number

NCT01802632; NCT02094261.

Ultra-sensitive EGFR T790M Detection as an Independent Prognostic Marker for Lung Cancer Patients Harboring EGFR del19 Mutations and Treated with First-generation TKIs

PURPOSE

The detection of preexisting EGFR ^T790M subclones and the assessment of their clinical significance in the pretreatment of patients with EGFR ^T790M non-small cell lung cancer (NSCLC) remain unclear.

EXPERIMENTAL DESIGN

A total of 179 tumor samples from patients treated or not with a first-generation tyrosine kinase inhibitor (TKI) was analyzed. The presence of ultra-low levels of preexisting EGFR^T790M mutation was evaluated using ultra-sensitive droplet digital PCR (ddPCR) and the clinical implication of these mutations on first-generation TKI efficiency assessed.

RESULTS

With a ddPCR linear performance of 0.999 and an analytical sensitivity of approximately 0.001%, we observed a 66% (99/150) overall incidence of ultra-low EGFR ^T790M mutation. Among 82 patients harboring EGFR ^activating mutations, the presence of a preexisting EGFR ^T790M mutation prior to any treatment was significantly associated with a longer progression-free survival (PFS; P = 0.009; log-rank test). Interestingly, longer PFS was linked to concomitant EGFR ^del19 and ultra-low EGFR ^T790M mutations. Moreover, the presence of both EGFR ^del19 and ultra-low EGFR ^T790M mutations was identified as the best fit for predicting the clinical outcome of patients treated with TKI compared with an ultra-low EGFR ^T790M mutation status or an activating mutation alone (P = 0.042 and P = 0.0071, respectively).

CONCLUSIONS

We demonstrate that the detection of the ultra-low EGFR ^T790M mutation in TKI-naïve patients is not a rare event. We suggest that ddPCR should be used in clinical practice to distinguish patients who may respond to first- or third-generation TKIs.

Receptor tyrosine kinases in PI3K signaling: The therapeutic targets in cancer

The phosphoinositide 3-kinase (PI3K) pathway, one of the most commonly activated signaling pathways in human cancers, plays a crucial role in the regulation of cell proliferation, differentiation, and survival. This pathway is usually activated by receptor tyrosine kinases (RTKs), whose constitutive and aberrant activation is via gain-of-function mutations, chromosomal rearrangement, gene amplification and autocrine. Blockage of PI3K pathway by targeted therapy on RTKs with tyrosine kinases inhibitors (TKIs) and monoclonal antibodies (mAbs) has achieved great progress in past decades; however, there still remain big challenges during their clinical application. In this review, we provide an overview about the most frequently encountered alterations in RTKs and focus on current therapeutic agents developed to counteract their aberrant functions, accompanied with discussions of two major challenges to the RTKs-targeted therapy in cancer - resistance and toxicity.

Survival benefit of first-generation epidermal growth factor receptor-tyrosine kinase inhibitors in female with advanced lung cancer

BACKGROUND

This study aimed to estimate therapeutic effects of first-generation epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) in real-world practice, by analyzing survival outcomes in an unselected, Korean female population with advanced lung cancer based on the National Health Insurance Service database.

METHODS

We identified women with newly diagnosed advanced lung cancer from January 2004 to December 2013. For progression-free survival (PFS) and overall survival (OS) analyses, patients were defined into the following subgroups: group A, treated with first-generation EGFR-TKI ⩾6 months; group B, treated with EGFR-TKIs <6 months but at least >1 month; and group C, treated with cytotoxic chemotherapy as follows: monotherapy or combination therapy with gemcitabine or pemetrexed; or monotherapy with docetaxel, paclitaxel, or vinorelbine.

RESULTS

Among 11,045 enrolled patients, 6170 (55.8%) were treated with first-generation EGFR-TKIs for at least 1 month. The median OS for patients treated with EGFR-TKIs was significantly longer than that of EGFR-TKI-naive patients (19.1 months [95% confidence interval (CI) 18.5-19.7] vs 9.5 months [95% CI 9.1-9.8], P<0.001). In subgroup analysis, group A had a significantly longer median OS compared with group B (30.3 months [95% CI 29.5-31.2] vs 12.3 months [95% CI 11.9-12.7], P<0.001). The median PFS of group A was significantly longer than that of group B (15.8 vs 3.7 months, P<0.001).

CONCLUSIONS

Our analysis demonstrates that EGFR-TKIs confer significant PFS and OS benefits in the real-world practice for Korean female with advanced lung cancer.

Afatinib in the first-line treatment of patients with non-small cell lung cancer: clinical evidence and experience

Epidermal growth factor receptor ( EGFR) gene mutations identify a molecularly defined subset of non-small cell lung cancer (NSCLC) patients who display an excellent sensitivity to EGFR tyrosine kinase inhibitors (TKIs). First-generation reversible EGFR TKIs, gefitinib and erlotinib have been proven to improve the objective response rate and to prolong the progression-free survival compared with standard chemotherapy in large phase III trials. Unfortunately, virtually all patients develop resistance to treatment, usually within 9-12 months. Afatinib is an irreversible ErbB family inhibitor initially designed to overcome the development of resistance. Compared with gefitinib in a first-line setting, afatinib prolonged progression-free survival and time to treatment failure, without impacting on overall survival in the general population of EGFR-mutant patients. However, afatinib has been shown to prolong overall survival in the subset of patients with an EGFR exon 19 deletion compared with chemotherapy. The aim of this review is to summarize the clinical evidence available to date and to critically discuss the place in therapy of afatinib in the rapidly expanding landscape of EGFR-mutant NSCLC first-line therapy.

TAS-121, A Selective Mutant EGFR Inhibitor, Shows Activity Against Tumors Expressing Various EGFR Mutations Including T790M and Uncommon Mutations G719X

TAS-121 is a novel orally active selective covalent inhibitor of the mutant EGFR. We performed preclinical characterization of TAS-121 and compared its efficacy and selectivity for common EGFR mutations (Ex19del and L858R), first- and second- generation EGFR-tyrosine kinase inhibitor (EGFR-TKI) resistance mutation (T790M), and uncommon mutations (G719X and L861Q) with those of other EGFR-TKIs. We also commenced investigation of the clinical benefits of TAS-121. The IC₅₀ for intracellular EGFR phosphorylation was determined by using Jump-In GripTite HEK293 cells transiently transfected with EGFR expression vectors. Mouse xenograft models were used to evaluate the antitumor activity of TAS-121. TAS-121 potently inhibited common activating and resistance EGFR mutations to the same extent as another third-generation EGFR-TKI (osimertinib). In addition, TAS-121 showed equivalent inhibitory activity against some uncommon mutations such as G719X and L861Q. Furthermore, TAS-121 demonstrated greater selectivity for mutant EGFRs versus the wild-type EGFR compared with other EGFR-TKIs. Moreover, TAS-121 displayed antitumor activity in SW48 (EGFR G719S) and NCI-H1975 (EGFR L858R/T790M) xenograft models, and achieved an objective response in patients with NSCLC with EGFR mutations including G719A mutation. In conclusion, TAS-121 is a novel third-generation EGFR-TKI and demonstrates antitumor activities in patients with NSCLC expressing either common or uncommon EGFR mutations.

Strategies to overcome acquired resistance to EGFR TKI in the treatment of non-small cell lung cancer

Epidermal growth factor receptor tyrosine kinase inhibitor (EGFR TKI) represents a paradigm shift in the treatment of non-small cell lung cancer (NSCLC) patients and has been the first-line therapy in clinical practice. While erlotinib, gefitinib and afatinib have achieved superior efficacy in terms of progression-free survival and overall survival compared with conventional chemotherapy in NSCLC patients, most people inevitably develop acquired resistance to them, which presents another challenge in the treatment of NSCLC. The mechanisms of acquired resistance can be classified as three types: target gene mutation, bypass signaling pathway activation and histological transformation. And the most common mechanism is T790M which accounts for approximately 50% of all subtypes. Many strategies have been explored to overcome the acquired resistance to EGFR TKI. Continuation of EGFR TKI beyond progressive disease is confined to patients in asymptomatic stage when the EGFR addiction is still preserved in some subclones. While the combination of EGFR TKI and chemotherapy or other targeted agents has improved the survival benefit in EGFR TKI resistant patients, there are controversies within them. The next-generation EGFR TKI and immunotherapy represent two novel directions for overcoming acquired resistance and have achieved promising efficacy. Liquid biopsy provides surveillance of the EGFR mutation by disclosing the entire genetic landscape but tissue biopsy is still indispensable because of the considerable rate of false-negative plasma.

Targeting EGFR in Lung Cancer: Current Standards and Developments

Lung cancer is the second most common malignant tumor and the leading cause of cancer death. Epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) is a distinct subtype of lung cancer comprising approximately 15-40% of non-squamous tumors. The development of first- and second-generation EGFR tyrosine kinase inhibitors (TKIs) has been a significant step forward in the treatment of patients with EGFR-mutant tumors, and over the last few years has been the therapy of choice in the initial management of patients with activating mutations in EGFR, with some differences in efficacy and toxicity profile. Up to 50% of patients treated with first- and second-generation TKIs develop an EGFR exon 20 T790M mutation at the time of progression. In this context, osimertinib has shown a great benefit in terms of progression-free survival (PFS) in the second-line setting, including central nervous system metastasis control. The FLAURA trial, which compared osimertinib to first-generation inhibitors as first-line therapy, showed a clear PFS advantage for osimertinib and a trend towards an increased overall survival (OS) assessed by investigator review. Although T790M mutation is the most common mechanism of resistance to first- and second-generation EGFR TKIs, other EGFR-dependent and -independent mechanisms have been described, such as HER2 and MET amplifications or BRAF and MEK mutations. Some mechanisms of resistance to osimertinib and other third-generation TKIs have also been described. Several fourth-generation TKIs, targeted drug combinations and immunotherapy strategies are under investigation to overcome resistance to EGFR TKIs in order to improve EGFR-mutant NSCLC patient outcomes.

Targeting EGFR exon 20 insertion mutations in non-small cell lung cancer

Inframe insertions of three or more base pairs in exon 20 of the epidermal growth factor receptor (EGFR) gene were among the first EGFR mutations to be identified as oncogenic drivers in non-small cell lung cancer (NSCLC). However, unlike the classical EGFR L858R point mutation or exon 19 deletions, which represent the majority of EGFR mutations in NSCLC, low frequency EGFR exon 20 insertion mutations are associated with de novo resistance to targeted EGFR inhibitors and correlate with a poor patient prognosis. Here, we review the developments over the last 5 years in which pre-clinical studies, including elucidation of the crystal structure of an EGFR exon 20 insertion mutant kinase, have revealed a unique mechanism of kinase activation and steric conformation that define the lack of response of these EGFR mutations to clinically approved EGFR inhibitors. The recent development of several novel small molecule compounds that selectively inhibit EGFR exon 20 insertions holds promise for future therapeutic options that will be effective for patients with this molecular subtype of NSCLC.

Real-World Data of the Correlation between EGFR Determination by Liquid Biopsy in Non-squamous Non-small Cell Lung Cancer (NSCLC) and the EGFR Profile in Tumor Biopsy

EGFR-mutated non-small cell lung cancer (NSCLC) has significant improved outcomes when treated with EGFR-tyrosine kinase inhibitors (TKI). Thus, EGFR-mutational status should be assessed at diagnosis and in the course of treatment with TKI. However, tissue samples are not always evaluable, and molecular profiling has been increasingly performed in cell-free tumor DNA (ctDNA) from blood samples. Our objective is to evaluate the reliability of ctDNA profiling in plasma samples in a real-world setting. We retrospectively analyzed the patients diagnosed with non-squamous NSCLC from May 2016 to December 2017 at Hospital Universitario Doctor Peset who had been tested for EGFR mutations in tissue and plasma samples. Both samples were sent to an external laboratory to perform the analysis by the cobas® EGFR assay. Percentage of agreement and concordance were calculated by kappa statistic. Of 102 patients reviewed, 89 were eligible. The overall EGFR mutation frequency was 18.6% for the evaluable tissue samples and 19.6% for evaluable plasma samples. Mutation status concordance between matched samples was 87.4%. Cohen's kappa index (κ) = 0.6 (sensitivity 70.6%, specificity 91.7%, positive predictive value 66.7%, negative predictive value 93%). When concordance was stablished only in stage IV tumors κ = 0.7, suggesting a higher agreement in advanced disease. This real-world data suggest that plasma is a feasible sample for ctDNA EGFR mutation assessment. Results of ctDNA molecular profiling are reliable when using a validated technique such as the cobas® EGFR assay, especially in patients that cannot undergo a tissue biopsy.

Role of osimertinib in the treatment of EGFR-mutation positive non-small-cell lung cancer

Mutations in the EGFR occur in approximately 10–35% of non-small-cell lung cancer (NSCLC) patients. Osimertinib is a third-generation oral small molecule inhibitor of EGFR, active against the common targetable activating EGFR mutations in L858R and exon 19 deletion; it also inhibits the T790M mutation. It was initially developed and approved for the treatment of acquired resistance to EGFR inhibition mediated by the T790M pathway activation. Recently, the FLAURA trial showed significantly improved progression-free survival with osimertinib compared with the first generation EGFR tyrosine kinase inhibitors gefitinib or erlotinib; this has led to its approval by US FDA and European Medicines Agency (EMA) as frontline therapy. Ongoing studies will define the resistance mechanisms to osimertinib, novel combination approaches and role in earlier stages of NSCLC.

Efficacy and safety of ultrasound (US) guided percutaneous needle biopsy for peripheral lung or pleural lesion: comparison with computed tomography (CT) guided needle biopsy

Background

Ultrasound (US)-guided percutaneous needle biopsy is a useful diagnostic technique with short examination time and real-time monitoring at the bedside. However, there are only a few studies that report on thoracic lesions, whereas the computed tomography (CT)-guided biopsy is well established. There is also limited data comparing US- and CT-guided biopsy. We aimed to clarify the efficacy and safety of US-guided biopsy for thoracic lesions adjacent to the chest wall.

Methods

We retrospectively enrolled consecutive patients who underwent US- or CT-guided percutaneous biopsies for thoracic lesions adjacent to the chest wall between April 2012 and December 2017. Clinical characteristics, lesion size, lesion-pleura contact arc length (LPCAL), diagnostic rate, and complications were compared between the 2 groups.

Results

This study enrolled 61 US-guided and 70 CT-guided biopsies. No significant difference was found in age or sex. The lesion size and LPCAL in the US-guided group were significantly larger than those in the CT-guided group (P<0.0001). The diagnostic rate was marginally higher in the US-guided group (93.4%) than in the CT-guided group (84.3%) (P=0.101). When the median cut-off of the LPCAL was defined as 40 mm in all cases, the diagnostic rate for lesion size >40 mm was significantly higher in the US-guided group than in the CT-guided group (P=0.009). Complication rates were significantly lower in the US-guided group (3.3%) than in the CT-guided group (24.3%) (P<0.001).

Conclusions

US-guided percutaneous needle biopsy for thoracic lesions adjacent to the chest wall is a feasible technique compared with CT-guided biopsy because of its higher diagnostic rate with a longer LPCAL and reduced complications.

Provisional Guideline Recommendation for EGFR Gene Mutation Testing in Liquid Samples of Lung Cancer Patients: A Proposal by the Korean Cardiopulmonary Pathology Study Group

Liquid biopsy for detection of mutation from circulating tumor DNA is a new technology which is attractive in that it is non-invasive. Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKI) is an effective first line drug for advanced non-small cell lung cancer patients who harbor activating EGFR mutation. During the course of treatment, resistance against TKI arises which can be contributed to EGFR T790M mutation in about 50-60% of patients. Third generation TKI may overcome the resistance. In patients who cannot undergo tissue biopsy due to variable reasons, liquid biopsy is an excellent alternative for the detection of EGFR T790M mutation. However, this relatively novel method requires standardization and vigorous quality insurance. Thus, a standard set of guideline recommendations for liquid biopsy for EGFR mutation testing suitable for the Korean medical community is necessary. In this article, we propose a set of provisional guideline recommendations that was discussed and approved by the Cardiopulmonary Pathology Study Group of the Korean Society of Pathologists.

Histopathological Features of Drug-Induced Liver Injury Secondary to Osimertinib

In the past few years, a better understanding of the genomic alterations in lung cancer has facilitated a targeted therapy. Lung adenocarcinomas with epidermal growth factor receptor mutations have a good response to tyrosine kinase inhibitors (TKIs). Osimertinib is a third-generation TKI approved by the Food and Drug Administration (FDA). Drug-induced liver injury is a well-known adverse effect of TKIs as a group and reported to show an autoimmune hepatitis-like picture. However, little is known about the histopathologic changes with osimertinib. We present a case of drug-induced liver injury secondary to osimertinib and discuss the histopathologic findings.

Impact on prognosis of rebiopsy in advanced non-small cell lung cancer patients after epidermal growth factor receptor-tyrosine kinase inhibitor treatment: a systematic review

Background

Osimertinib, the third-generation epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI), has become the standard treatment in cases where rebiopsy reveals T790M mutation after the first-line EGFR-TKI treatment. However, the prognosis of patients after rebiopsy, the most important outcome for cancer patients, has not been described sufficiently. This systematic review aimed to clarify whether rebiopsy contributes to improved prognosis in the first- or second-generation EGFR-TKI refractory patients.

Methods

Using free word and control terms related to “non-small cell lung cancer” and “rebiopsy,” we searched studies from Medical Literature Analysis and Retrieval System Online via PubMed, Embase, Cochrane Central Register of Controlled Trials, and World Health Organization International Clinical Trials Registry Platform. We included cohort studies and case reports written in English and judged whether each study answers our research questions.

Results

Of the 144 studies included, only one reported the prognosis of patients with/without rebiopsy showing that in EGFR-TKI refractory non-small cell lung cancer patients, the post-progression survival (PPS) was significantly longer in patients who received rebiopsy and treatment based on a resistant mechanism (median PPS 24.2 months) than those who received rebiopsy and salvage regimen (median PPS 15.2 months, p = 0.002) and who did not receive rebiopsy (median PPS 9.7 months, p < 0.001). Most of the other studies reported the detection rate of T790M mutation or rebiopsy procedure.

Conclusions

Only a few previous studies have investigated the effectiveness of rebiopsy. Hence, further study is needed to determine the prognosis or adverse events of rebiopsy.

Acquisition of T790M resistance mutation in a patient with advanced adenocarcinoma harbouring uncommon EGFR mutations: a case report and literature review

Background

Osimertinib is the standard of care for patients with non-small-cell lung cancer (NSCLC) patients harboring acquired EGFR T790M resistance mutation. However, the frequency of T790M resistance mutation acquisition and the efficacy of osimertinib in patients harboring uncommon EGFR mutations, which accounts for approximately 10% of EGFR mutations, remain unclear.

Case presentation

We present the case of a 72-year-old Japanese woman with recurrent NSCLC harboring uncommon EGFR mutations, who was subsequently found to have acquired the T790M resistance mutation and was treated with osimertinib. She died 9 days later because of worsening respiratory failure with disease progression.

Conclusion

The findings of the present case suggest that the T790M resistance mutation can occur even when the patient harbors an uncommon EGFR mutation after EGFR-tyrosine kinase inhibitor treatment, and the prognosis could be poor despite the presence of an acquired T790M resistance mutation.

Efficacy and safety of osimertinib in treating EGFR-mutated advanced NSCLC: A meta-analysis

Osimertinib is the only Food and Drug Administration-approved third-generation epidermal growth factor receptor (EGFR) tyrosine-kinase inhibitor (TKI). A meta-analysis was performed to aggregate the mixed results of published clinical trials to assess the efficacy and safety of osimertinib. A systematic search of the PubMed, Web of Science, and Cochrane Library electronic databases was performed to identify eligible literature. The primary endpoints were overall response rate (ORR), disease control rate (DCR), progression-free survival (PFS), and adverse events (AEs). A total of 3,086 advanced nonsmall cell lung cancer (NSCLC) patients from 11 studies have been identified. The aggregate efficacy parameters for treatment-naïve patients with EGFR-TKI-sensitizing mutations are as follows: ORR 79% (95% CI 75-84%), DCR 97% (95% CI 95-99%), 6-month PFS 83% (95% CI 80-87%), and 12-month PFS 64% (95% CI 59-69%). The aggregate efficacy parameters for advanced NSCLC harboring T790M mutations after earlier-generation EGFR-TKI therapy are as follows: ORR 58% (95% CI 46-71%), DCR 80% (95% CI 63-98%), 6-month PFS 63% (95% CI 58-69%), and 12-month PFS 32% (95% CI 17-47%). EGFR-TKI-naïve patients with EGFR-positive mutations tend to have longer median PFS than EGFR-TKI-pretreated counterparts (19.17 vs. 10.58 months). The most common AEs were diarrhea and rash, of which the pooled incidences were 44 and 42%, respectively. Generally, osimertinib is a favorable treatment option for previously treated T790M mutation-positive advanced NSCLC as well as a preferable therapy for untreated EGFR mutation-positive advanced NSCLC. Additionally, osimertinib is well tolerated by most patients.

Erlotinib and bevacizumab combination therapy for afatinib-refractory leptomeningeal carcinomatosis from EGFR-mutated lung cancer

Acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitors remains the main hurdle in treating EGFR-mutated lung cancer. Besides, when leptomeningeal carcinomatosis occurs during treatment, it often leads to treatment failure. We herein report a case of lung adenocarcinoma involving a patient with an EGFR exon 19 deletion mutation who developed leptomeningeal carcinomatosis after afatinib treatment for post-operative recurrence. He received right lower lobectomy, followed by four cycles of cisplatin and pemetrexed treatment. Follow-up CT/MRI revealed multiple pulmonary metastases and brain metastases at 7 months after surgery, and afatinib (40 mg/day) was administered after stereotactic radiotherapy for brain metastasis. At 28 months after surgery, follow-up MRI revealed asymptomatic leptomeningeal carcinomatosis, which was cytologically proven from the cerebrospinal fluid. Because EGFR T790M was not detected in plasma cell-free DNA or cerebrospinal fluid, erlotinib and bevacizumab combination treatment was administered. He remained asymptomatic and was radiographically clear of LM at 2 months after treatment. In comparison to other EGFR-TKIs, erlotinib shows penetrance into the cerebrospinal fluid. Furthermore, the addition of bevacizumab might enhance the treatment effect, because it is known to relieve brain edema from metastatic brain tumors by normalizing immature vascularity and improving drug penetrance into the cerebrospinal fluid by reducing interstitial fluid pressure.

Efficacy, safety, and resistance profile of osimertinib in T790M mutation-positive non-small cell lung cancer in real-world practice

The efficacy and safety of osimertinib were demonstrated in clinical trials; however, real-world clinical data, particularly the resistance profile, are limited. Here, we investigated the efficacy, safety, and resistance profile of osimertinib in real-world practice. We reviewed medical records of T790M mutation-positive lung cancer patients who started osimertinib between February 2016 and June 2017. Molecular pathologic data of biopsy samples obtained after acquisition of resistance to osimertinib were also analyzed. The study included 23 patients with a median age of 59 years. The median follow-up duration was 11.9 months (IQR, 4.7–15.8). Objective response was achieved in 17 (73.9%) patients, and the disease was controlled in 22 (95.7%) patients. Median progression-free survival (PFS) was 7.4 months (95% CI, 3.6–11.0). Adverse events were minimal except for one case of pneumonitis. Of 14 patients experiencing disease progression, 10 underwent re-biopsy. The T790M mutation disappeared in seven patients (70%), and one showed wild-type conversion. PFS was shorter in the T790M-loss group than in the T790M-persistent group (4.4 vs. 7.7 months). Two patients with small cell transformation responded well to subsequent chemotherapy. One patient developed a C797S mutation that became undetectable after two cycles of gemcitabine and cisplatin followed by six cycles of pembrolizumab, after which the patient responded well to osimertinib. In conclusion, osimertinib showed favorable efficacy and safety in real-world practice comparable to those observed in clinical trials. Repeat biopsy after the acquisition of resistance to osimertinib is helpful to direct further treatment strategies.

The Roles of Common Variation and Somatic Mutation in Cancer Pharmacogenomics

Cancer pharmacogenomics is the science concerned with understanding genetic alterations and its effects on the pharmacokinetics and pharmacodynamics of anti-cancer drugs, with the aim to provide cancer patients with the precise medication that will achieve a good response and cause low/no incidence of adverse events. Advances in biotechnology and bioinformatics have enabled genomic research to evolve from the evaluation of alterations at the single-gene level to studies on the whole-genome scale using large-scale genotyping and next generation sequencing techniques. International collaborative efforts have resulted in the construction of databases to curate the identified genetic alterations that are clinically significant, and these are currently utilized in clinical sequencing and liquid biopsy screening/monitoring. Furthermore, countless clinical studies have accumulated sufficient evidence to match cancer patients to therapies by utilizing the information of clinical-relevant alterations. In this review we summarize the importance of germline alterations that act as predictive biomarkers for drug-induced toxicity and drug response as well as somatic mutations in cancer cells that function as drug targets. The integration of genomics into the medical field has transformed the era of cancer therapy from one-size-fits-all to cancer precision medicine.

Different characteristics and survival in non-small cell lung cancer patients with primary and acquired EGFR T790M mutation

Primary epidermal growth factor receptor (EGFR) T790M mutation can be occasionally identified in previous untreated nonsmall cell lung cancer (NSCLC) patients. To compare clinical characteristics and outcomes in patients with primary and acquired EGFR T790M mutation, we collected the data of patients diagnosed with EGFR mutation from 2012 to 2017 in Shanghai Chest Hospital. Primary EGFR T790M mutation was identified in 61 patients (1.1%; 95% confidence interval (CI): 0.8%-1.3%) of 5685 TKI-naive EGFR mutant patients. Acquired T790M mutation was detected in 98 patients (50.3%; 95%CI: 43.2%-57.3%) of 195 TKI-treated patients. T790M mutation always coexisted with sensitizing EGFR mutations. Primary EGFR T790M always coexisted with 21L858R (46/61) whereas acquired T790M coexisted with 19del (68/98), (p < 0.001). Among them, 18 patients with primary T790M mutation received osimertinib and 72 patients with acquired T790M mutation received osimertinib. The median progression-free survival (PFS) of osimertinib was significantly longer in primary T790M group (17.0 months, 95%CI:14.0-20.0 months) compared to acquired T790M group (10.0 months, 95%CI:8.6-11.4 months, p = 0.022). However, the median overall survival (OS) of acquired T790M mutation patients was significantly longer compared to that of primary T790M mutation patients who received osimertinib (50.4 months vs. 29.9 months, p = 0.016). Our findings suggest that primary T790M mutation likely coexists with 21L858R while acquired mutation likely coexists with 19del. Both mutations showed good response to osimertinib. Patients with primary T790M mutation experienced greater benefits from osimertinib. However, patients with acquired T790M mutation had a better overall survival during the entire clinical treatment.

Advanced Non-Small Cell Lung Cancer with Activating Epidermal Growth Factor Receptor Mutation: First Line Treatment and Beyond

BACKGROUND

Lung cancer is the leading cause of cancer mortality, being responsible for more than 1.6 million deaths each year worldwide and non-small-cell lung cancer (NSCLC) accounts for approximately 85% of lung cancers; moreover, 10 to 15% of all NSCLCs harbor EGFR (epidermal growth factor receptor) activating mutations, being suitable for EGFR-Tyrosine Kinase Inhibitors (TKI) molecular targeted therapy. However, EGFR+ NSCLCs gain acquired resistance to these agents, representing one of the key challenges for modern precision oncology.

OBJECTIVE

Therefore, this paper aims to provide an extensive state of the art review, alongside with hints about future perspectives.

CONCLUSION

To date, in the light of the data from the FLAURA study, osimertinib represents the best first-line option in NSCLC patients with EGFR activating mutations; EGFR-TKI plus chemotherapy combination therapies, even though interesting, must still be considered investigational.

Prevalence of ROS1 fusion in Chinese patients with non-small cell lung cancer

BACKGROUND

The study was conducted to investigate the clinicopathological features and prevalence of ROS1 gene fusion in Chinese patients with non-small cell lung cancer (NSCLC).

METHODS

The presence of ROS1 fusion was assessed by quantitative real-time PCR. Associations between ROS1 fusion and clinical characteristics were analyzed.

RESULTS

In total, 6066 patients with pathologically confirmed NSCLC and ROS1 fusion test results were enrolled. The average age was 60.89 ± 10.60 years and fusion was detected in 157 (2.59%) patients. Fusion frequency was significantly correlated with age, gender, smoking status (all P < 0.001), pathology type (P = 0.017), and lymph node metastasis stage (P = 0.027). ROS1 fusion-positive patients were significantly younger (55.68 ± 11.34 vs. negative 61.02 ± 10.44 years; P < 0.01). Fusion frequency was higher in women (3.71% vs. men 1.81%), never-smokers (3.33% vs. smokers 1.21%), and patients with adenocarcinoma (2.77% vs. squamous lung cancer 0.93%) and at advanced node stages (1.31%, 1.40%, 2.07%, and 3.23% for N0, N1, N2, and N3, respectively). No significant correlation between ROS1 fusion status and pathological stage was found in subgroups classified by pathological, tumor, or metastasis stage (P > 0.05). Age, smoking status, and lymph node stage were statistically significantly correlated with ROS1 fusion frequency (all P < 0.05); gender and pathology type were not significantly correlated with ROS1 fusion status after adjusting for smoking status.

CONCLUSION

An overall ROS1 fusion frequency of 2.59% was confirmed in this study. ROS1 fusion was more prevalent among younger patients, never-smokers, and those at advanced node stages.

A "triple whammy" in adenocarcinoma lung

Osimertinib (AZD9291), a third-generation epidermal growth factor receptor (EGFR)-tyrosine-kinase inhibitor (TKI), is useful in the treatment of non-small cell lung cancer who show resistance to first-generation EGFR-TKIs and harbor T790M mutation. Acquisition of resistance to osimertinib due to several mechanisms has been reported. We report the first case of an Indian patient with osimertinib resistance, due to C797S mutation. A 52-year-old nonsmoker man was detected to have metastatic lung adenocarcinoma (Stage IV) with EGFR exon 19 deletion and treated with erlotinib. After 12 months of response with erlotinib, he developed resistance because of the development of T790M mutation. He was started on osimertinib, with which he responded for 20 months. A follow-up positron emission tomography scan showed progressive disease. Subsequent liquid biopsy did not detect any mutation. However, rebiopsy of the lung lesion showed additional C797S mutation (in cis association with T790M). Hence, the patient was diagnosed to have “triple whammy,” i.e., triple mutation of exon 19 deletion, T790M, and C797S mutations.

Curative effectiveness and safety of osimertinib in the treatment for non-small-cell lung cancer: a meta-analysis of the experimental evidence

Background

Osimertinib is an EGFR-TKI that is selective for both EGFR-TKI-sensitizing and T790M resistance mutations in patients with non-small-cell lung cancer (NSCLC). The purpose of this study was conducting a meta-analysis to evaluate the clinical efficacy and safety of osimertinib in the treatment for NSCLC.

Methods

Using “osimertinib” as a keyword combined with “non-small-cell lung cancer” and “randomized controlled trial” as medical subject headings, the following electronic databases were searched: PubMed, EMBASE, Cochrane Library, and China National Knowledge Infrastructure. After data extraction and quality assessment of the included randomized controlled trials, the RevMan 5.3 software and R meta package were applied for meta-analysis of objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), overall survival (OS), and safety.

Results

Ten studies met our criteria and were included in the meta-analysis, with a total of 3,260 participants. The meta-analysis showed that osimertinib therapy was superior to the control therapy alone in ORR (combined RR=1.53, 95% CI: 0.87–2.71, P=0.14), DCR (combined RR=1.07, 95% CI: 0.79–1.44, P=0.66), PFS (combined RR=0.32, 95% CI: 0.24–0.44, P<0.00001), and OS (combined RR=0.57, 95% CI: 0.47–0.70, P<0.00001). In addition, osimertinib led to some toxicities, and the overall prevalence of all-grade diarrhea was 40% (95% CI: 33–47), paronychia 26% (95% CI: 20–33), rash 40% (95% CI: 34–47), dry skin 28% (95% CI: 23–33), and stomatitis 15% (95% CI: 9–23).

Conclusion

Our study showed that osimertinib demonstrated a significant improvement in the ORR, DCR, PFS, and OS with tolerable adverse effects for NSCLC patients. However, because of some clear limitations (heterogeneity and publication bias), these results should be interpreted with caution.

T790M Correlates with Longer Progression-free Survival in Non-small Cell Lung Carcinomas Harboring EGFR Mutations

BACKGROUND/AIM

The aim of this study was to evaluate the relationship between T790M status and the characteristics of non-small cell lung cancer (NSCLC) patients undergoing rebiopsy after initial epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) therapy and whether the site of rebiopsy has an effect on the detection rate for T790M in these patients.

MATERIALS AND METHODS

We retrospectively reviewed the clinical data from stage IV or recurrent NSCLC patients who harbored EGFR mutations and who had initially received EGFR-TKI at our Center from January 2009 to December 2016.

RESULTS

Overall, 129 patients were included. The median age at EGFR-TKI therapy initiation was 73 years and 110 showed progressive disease. The presence of T790M mutation was associated with significantly longer progression-free survival (PFS) and EGFR mutation status. The participants' characteristics and rebiopsy site did not affect the T790M detection rate.

CONCLUSION

It is highly recommended that patients with exon 19 deletions and long PFS undergo screening for T790M.

Safety of osimertinib in EGFR-mutated non-small cell lung cancer

INTRODUCTION

Osimertinib is a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI), specifically designed to inhibit EGFR sensitizing and T790M acquired mutations, minimizing exposure in EGFR-wild-type tissues. Areas covered: Osimertinib use in EGFR-mutated non-small cell lung cancer patients is described, focusing on safety and tolerability from studies supporting its approval. Expert opinion: Osimertinib demonstrated greater efficacy, including CNS activity, compared to chemotherapy, with a manageable safety profile in pretreated T790M+ EGFR-mutated patients, leading to FDA approval in 2015 within record time in the oncology field. However, the therapeutic strategy in the EGFR-mutated population is changing, following the FLAURA study in untreated EGFR-mutated patients, in which osimertinib improved progression-free survival compared to other TKIs, with a similar toxicity profile but a lower serious adverse event rate. In April 2018, the FDA and EMA approved osimertinib as first-line therapy for EGFR-mutated patients. Long-term survival data will ultimately establish the true benefit of upfront versus sequential strategies guided by T790M status. These studies favor osimertinib for tolerability and safety, except for the slightly higher rate of interstitial lung disease, but which was nonetheless manageable. In the coming years, osimertinib will be consolidated as standard therapy in the EGFR population and in naïve and pretreated patients, based on mature survival data and the toxicity profile.

Osimertinib in patients with T790M mutation-positive, advanced non-small cell lung cancer: Long-term follow-up from a pooled analysis of 2 phase 2 studies

BACKGROUND

Osimertinib is a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) that is selective for both EGFR-TKI-sensitizing and T790M (threonine-to-methionine substitution at codon 790)-resistance mutations. The authors present long-term follow-up data from a preplanned, pooled analysis of phase 2 studies, the AZD9291 First Time in Patients Ascending Dose Study (AURA) extension trial (clincialtrials.gov identifier NCT01802632) and the AURA2 trial (NCT02094261).

METHODS

Patients with centrally confirmed, T790M mutation-positive, advanced non-small cell lung cancer received osimertinib 80 mg once daily until disease progression or study discontinuation. Response was assessed by a blinded, independent, central review using Response Evaluation Criteria in Solid Tumors, version 1.1. The primary endpoint was the objective response rate.

RESULTS

In total, 411 patients received osimertinib (second line, 129 patients; third line or later, 282 patients). At the data cutoff date of November 1, 2016, the median treatment exposure was 16.4 months (range, 0-29.7 months), the objective response rate was 66% (95% confidence interval [CI], 61%-70%), the median response duration was 12.3 months (95% CI, 11.1-13.8 months), and the median progression-free survival was 9.9 months (95% CI, 9.5-12.3 months). At the data cutoff date of May 1, 2018, 271 patients (66%) had died, and 140 patients (34%) had discontinued before death. The median overall survival was 26.8 months (95% CI, 24.0-29.1 months); and the 12-month, 24-month, and 36-month survival rates were 80%, 55%, and 37%, respectively. Grade ≥3 possibly causally related (investigator assessed) adverse events were reported in 65 patients (16%), and the most common were rash (grouped terms; 42%; grade ≥3, 1%) and diarrhea (39%; <1%).

CONCLUSIONS

This pooled analysis represents the most mature clinical trial data for osimertinib in patients with pretreated, T790M-positive, advanced non-small cell lung cancer, further establishing osimertinib as a standard of care for this patient population.

Real-life efficacy of osimertinib in pretreated patients with advanced non-small cell lung cancer harboring EGFR T790M mutation

Objectives The efficacy of osimertinib in pretreated patients with advanced non-small cell lung cancer (NSCLC) harboring EGFR T790 M resistance mutation was demonstrated in clinical trials. However, data on efficacy of osimertinib in real world remain rare. Materials and methods This retrospective multicentric study analyzed T790M-positive advanced NSCLC patients enrolled in French early access program for osimertinib. Patients were pretreated with first- or second-generation EGFR tyrosine-kinase inhibitor and for a majority with chemotherapy. Primary endpoints were progression-free survival (PFS) and overall survival (OS) from osimertinib initiation. Results 205 patients (mean age, 69.5 years; female, 68.8%; adenocarcinoma, 97.5%, never-smokers, 71.5%) were analyzed. Osimertinib was used in second and third line in 18.0% and 82.0% of patients, respectively. Median PFS was 12.4 (95% CI, 10.1-15.1) months. In patients with and without cerebral metastasis, PFS was 9.7 (7.7-13.5) and 15.1 (12.0-17.1) months (p = 0.21), respectively. PFS in second and third line or more was 12.6 (6.7-17.5) and 12.4 (9.7-15.3) months, respectively. Median PFS in patients with EGFR exon 19 deletion and exon 21 mutation was 13.5 (10.1-16.0) and 9.7 (7.4-13.2) months, respectively (p = 0.049). Median OS since osimertinib initiation was 20.5 (16.9-24.3) months: 23.1 (18.6-27.8) and 18.0 (12.2-22.2) months in patients without and with cerebral metastasis (p = 0.11); 17.5 (11.6-27.8) and 21.7 (17.3-24.3) months as second or third line of treatment or more (p = 0.46), respectively. Median OS in patients with EGFR exon 19 deletion and exon 21 mutation was 23.1 (18.6-25.7) and 15.3 (11.6-21.7) months, respectively (p = 0.03). Osimertinib dosage was modified in 8.0% of patients and definitively discontinued for adverse events in 5.9%. Fifty patients benefited from rebiopsy (persistence of T790 M mutation, 44.7%; C797S mutation, 21.1%; cMET amplification, 8.0%). Conclusion In pretreated patients with T790M-mutated advanced NSCLC, the efficacy of osimertinib appears similar in real-world setting to that of clinical trials.