Sequential treatment with afatinib and osimertinib in patients with EGFR mutation-positive non-small-cell lung cancer: an observational study

Switching from first or second generation EGFR-TKI to osimertinib in EGFR mutation-positive NSCLC

Aim:

We evaluated the efficacy of a novel switch protocol for EGFR-TKIs for EGFR mutation-positive NSCLC.

Materials & methods:

Clinical records were collected from the patients who had received one of two sequential combination strategies of EGFR-TKIs: Salvage use of osimertinib for T790M-mediated acquired resistance to an prior EGFR-TKI or switch use of osimertinib where an EGFR-TKI was switched to osimertinib before disease progression.

Results:

Progression-free survival of osimertinib and time from the start of treatment until progression to osimertinib was comparable between the salvage use and switch use of osimertinib.

Conclusion:

Switch use of osimertinib seemed to produce improved efficacy for patients with activating EGFR mutations, because of the lack of patient selection via T790M.

Observational Study of Sequential Afatinib and Osimertinib in EGFR Mutation-Positive NSCLC: Patients Treated with a 40-mg Starting Dose of Afatinib

Introduction

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are the standard of care for patients with EGFR mutation-positive non-small cell lung cancer (NSCLC). However, questions remain about the optimal treatment sequence of EGFR TKIs. The global, observational GioTag study demonstrated prolonged time on treatment with sequential afatinib and osimertinib therapy in patients who acquired the T790M mutation. Here, we assessed outcomes in patients who received the approved 40-mg starting dose of afatinib, as used in the clinical trial setting.

Methods

In the non-interventional, global, multicenter GioTag study, patients had T790M-positive disease following first-line afatinib and started osimertinib treatment ≥ 10 months prior to data entry. Primary outcome was time on treatment. This subanalysis assessed outcomes in patients who received afatinib 40 mg.

Results

In 169 patients who received an afatinib starting dose of 40 mg, median time on treatment was 27.6 months (90% confidence interval [CI] 26.3–31.3). Benefit was seen across patient subgroups, particularly those with Del19-positive disease and Asian patients; median time on treatment was 29.9 months (90% CI 27.6–46.7) in patients with Del19-positive disease and 46.7 months (90% CI 28.4–not reached) in Asian patients. The 2-year overall survival rate was 80%.

Conclusions

These real-world results support the overall study results and demonstrate prolonged time on treatment with sequential afatinib and osimertinib. The results suggest that sequential afatinib and osimertinib is a feasible therapeutic strategy for patients who acquire the T790M mutation, particularly those with Del19-positive disease or Asian patients.

Trial Registration Number

NCT03370770.

Electronic Supplementary Material

The online version of this article (10.1007/s12325-019-01187-y) contains supplementary material, which is available to authorized users.

Front-line Therapy in Advanced Non-Small Cell Lung Cancer With Sensitive Epidermal Growth Factor Receptor Mutations: A Network Meta-analysis

PURPOSE

Several epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) were firmly established as front-line treatment for non-small cell lung cancer (NSCLC) that harbored an activating EGFR mutation. Gefitinib or erlotinib was considered the standard of care. TKI-based combination therapy has been investigated and has shown encouraging results.

METHODS

The PubMed and EMBASE databases, the Cochrane Central Register of Controlled Trials, and meeting abstracts were screened for relevant studies between January 2000 and February 2019. Prospective randomized controlled trials were included that investigated EGFR TKIs (alone or in combination) in untreated patients with NSCLC whose tumors had sensitive EGFR mutations. A frequentist random effects network meta-analysis model was conducted to assess objective response rate, progression-free survival, and overall survival. P-score was used to rank treatment effects.

FINDINGS

Seventeen trials involving 9 treatments and 4373 patients were included. Heterogeneity existed in the network analysis. For progression-free survival, the top 3 treatments were osimertinib, standard of care plus chemotherapy, and standard of care plus bevacizumab; corresponding p-scores were 0.88, 0.79, and 0.75, respectively. For overall survival, the top 3 treatments were standard of care plus chemotherapy, osimertinib, and dacomitinib; corresponding p-scores were 0.89, 0.85, and 0.64. TKI-based combination therapy caused more toxicity than a TKI alone.

IMPLICATIONS

Osimertinib seemed to be a better option as upfront therapy for EGFR-mutant NSCLC in terms of efficacy and tolerability.

Tyrosine Kinase Inhibitors for the Treatment of EGFR Mutation-Positive Non-Small-Cell Lung Cancer: A Clash of the Generations

The availability of 3 generations of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) with different pharmacologic characteristics and clinical profiles has provided oncologists with a potentially confusing choice for the treatment of EGFR mutation-positive non-small-cell lung cancer. Although recent head-to-head clinical trials have demonstrated improved efficacy with second-generation (ie, afatinib, dacomitinib) and third-generation (ie, osimertinib) TKIs compared with the first-generation TKIs (eg, erlotinib, gefitinib), acquired resistance has been inevitable, regardless of which agent has been chosen as first-line therapy. Thus, the potential availability of subsequent treatment options is an important consideration. Recent data have demonstrated that osimertinib confers an overall survival benefit compared with first-generation EGFR TKIs, and dacomitinib has shown an overall survival benefit compared with gefitinib in an exploratory analysis. However, the relative benefits of different sequential EGFR-TKI regimens, especially those involving second- and third-generation agents, have remained uncertain and require prospective evaluation. Few such data currently exist to inform treatment choices. In the present review, we examined the pharmacologic characteristics and current clinical data for EGFR TKIs, including emerging information on the molecular mechanisms of resistance across the different generations of TKIs. Given the uncertainties regarding the optimal treatment choice, we have focused on the factors that might help determine the treatment decisions, such as efficacy and safety in patient subgroups. We also discussed the emerging real-world data, which have provided some insights into the benefits of sequential regimens in everyday clinical practice.

Impact of coexisting gene mutations in EGFR-mutated non-small cell lung cancer before treatment on EGFR T790M mutation status after EGFR-TKIs

OBJECTIVES

The T790M secondary mutation of epidermal growth factor receptor gene (EGFR) is the most common mechanism of acquired resistance to first- or second-generation EGFR tyrosine kinase inhibitors (TKIs). We investigated the association between gene mutation profile in EGFR mutation-positive non-small cell lung cancer (NSCLC) before EGFR-TKI treatment and T790M status after EGFR-TKI treatment.

MATERIALS AND METHODS

A total of 57 EGFR mutation-positive NSCLC patients who had undergone a repeat biopsy (tissue or liquid) after failure of treatment with a first- or second-generation EGFR-TKI and who had sufficient tumor tissue available from before treatment for genetic analysis was enrolled. The gene mutation profile of tumor tissue obtained before EGFR-TKI treatment was evaluated by next-generation sequencing with a comprehensive cancer gene panel (409 genes). The number of potentially damaging nonsynonymous mutations was predicted with PolyPhen-2 software.

RESULTS

Progression-free survival during EGFR-TKI treatment did not differ significantly between patients who developed T790M-mediated resistance and those who developed T790M-independent resistance. The predicted number of damaging nonsynonymous mutations in pretreatment tumor tissue was significantly lower in patients who developed T790M-mediated resistance than in those with T790M-independent resistance (P =  0.049).

CONCLUSIONS

Coexisting mutations in tumor tissue before EGFR-TKI treatment may contribute to the emergence of cell clones responsible for development of T790M-dependent or T790M-independent TKI resistance in patients with EGFR-mutated NSCLC. Multiplex genomic testing of pretreatment tumor tissue may thus provide a means of identifying patients likely to develop T790M-mediated TKI resistance and therefore inform treatment selection.

Efficacy of osimertinib for the treatment of previously EGFR TKI treated NSCLC patients: a meta-analysis

BACKGROUND

This study evaluates the efficacy of osimertinib for the treatment of previously epidermal growth factor receptor tyrosine kinase inhibitors (EFGR-TKI) treated non-small cell lung cancer (NSCLC) patients.

METHOD

Research articles reporting the efficacy of osimertinib for NSCLC patients were identified from literature databases (Embase, Ovid, PubMed and Scopus) by following pre-determined eligibility criteria. Response and survival data were extracted from study reports and were pooled under random-effects model to obtain overall/subgroup effect sizes of selected efficacy outcomes.

RESULTS

Nine studies (950 patients; age 60.1 years [95% confidence interval: 57.2, 63.1]; 65% [95% CI: 62, 69] females; 69% [35, 100] with T790M; 61% [53, 68] with ex19del; and 35% [29, 41] with L858R mutations). Osimertinib treatment was associated with a PFS of 11.17 months [7.80, 14.55] which was longer in treatment-naïve (20.30 [15.37, 25.23]) than in prior EGFR-TKI-treated (10.20 [9.60, 10.80]) patients. 1-year survival was 81.29% [73.25, 89.32]. Complete response rate was 1.48% [1.19, 1.76]. PR was achieved in 53.18% [24.18, 82.18] patients which differed between treatment-naïve and prior EGFR-TKI-treated patients (74.48 [65.59, 83.37] and 67.99% [62.68, 73.30], respectively. Objective response rate and disease control rates were 69.80% [64.84, 74.77] and 92.43% [89.42, 95.43], respectively, which did not differ between treatment-naïve and prior EGFR-TKI-treated patients.

CONCLUSION

Osimertinib treatment yields approximately 10 months PFS in prior EGFR-TKI-treated and 20 months in treatment-naïve NSCLC patients. Partial response rate is also higher in treatment-naïve patients. However, objective response rate (ORR) and disease control rate (DCR) did not differ between groups of patients.

Real-world experience of first-line afatinib in patients with EGFR-mutant advanced NSCLC: a multicenter observational study

BACKGROUND

This study aimed to evaluate the efficacy, side-effects and resistance mechanisms of first-line afatinib in a real-world setting.

METHODS

This is a multicenter observational study of first-line afatinib in Malaysian patients with epidermal growth factor receptor (EGFR)-mutant advanced non-small cell lung cancer (NSCLC). Patients' demographic, clinical and treatment data, as well as resistance mechanisms to afatinib were retrospectively captured. The statistical methods included Chi-squared test and independent t-test for variables, Kaplan-Meier curve and log-rank test for survival, and Cox regression model for multivariate analysis.

RESULTS

Eighty-five patients on first-line afatinib from 1st October 2014 to 30th April 2018 were eligible for the study. EGFR mutations detected in tumors included exon 19 deletion in 80.0%, exon 21 L858R point mutation in 12.9%, and rare or complex EGFR mutations in 7.1% of patients. Among these patients, 18.8% had Eastern Cooperative Oncology Group performance status of 2-4, 29.4% had symptomatic brain metastases and 17.6% had abnormal organ function. Afatinib 40 mg or 30 mg once daily were the most common starting and maintenance doses. Only one-tenth of patients experienced severe side-effects with none having grade 4 toxicities. The objective response rate was 76.5% while the disease control rate was 95.3%. At the time of analysis, 56 (65.9%) patients had progression of disease (PD) with a median progression-free survival (mPFS) of 14.2 months (95% CI, 11.85-16.55 months). Only 12.5% of the progressed patients developed new symptomatic brain metastases. The overall survival (OS) data was not mature. Thirty-three (38.8%) patients had died with a median OS of 28.9 months (95% CI, 19.82-37.99 months). The median follow-up period for the survivors was 20.0 months (95% CI, 17.49-22.51 months). Of patients with PD while on afatinib, 55.3% were investigated for resistance mechanisms with exon 20 T790 M mutation detected in 42.0% of them.

CONCLUSIONS

Afatinib is an effective first-line treatment for patients with EGFR-mutant advanced NSCLC with a good response rate and long survival, even in patients with unfavorable clinical characteristics. The side-effects of afatinib were manageable and T790 M mutation was the most common resistance mechanism causing treatment failure.

Sequential afatinib and osimertinib in patients with EGFR mutation-positive non-small-cell lung cancer: updated analysis of the observational GioTag study

Aims: Overall survival (OS) and updated time to treatment failure (TTF) analysis of patients with EGFR mutation-positive (Del19, L858R) non-small-cell lung cancer who received sequential afatinib/osimertinib in the real-world GioTag study. Patients & methods: Patients had T790M-positive disease following first-line afatinib and received osimertinib treatment (n = 203). Primary outcome was TTF. The OS analysis was exploratory. Results: Median OS was 41.3 months (90% CI: 36.8–46.3) overall and 45.7 months (90% CI: 45.3–51.5) in patients with Del19-positive tumors (n = 149); 2-year survival was 80 and 82%, respectively. Updated median TTF with afatinib and osimertinib was 28.1 months (90% CI: 26.8–30.3). Conclusion: Sequential afatinib/osimertinib was associated with encouraging OS/TTF in patients with EGFR T790M-positive non-small-cell lung cancer, especially in patients with Del19-positive tumors.

Trial registration number: NCT03370770

Optimizing outcomes and treatment sequences in EGFR mutation-positive non-small-cell lung cancer: recent updates

The availability of several EGFR tyrosine kinase inhibitors (TKIs) for the treatment of EGFR mutation-positive NSCLC poses important questions regarding the optimum sequence of therapy. A key consideration is how best to use the third-generation TKI, osimertinib. While osimertinib has demonstrated impressive efficacy and tolerability in a first-line setting, there are currently no standard targeted treatment options following progression. There is an argument, therefore, for reserving osimertinib for second-line use in patients who acquire the T790M resistance mutation after first- or second-generation TKIs. This article reviews recent clinical studies that have assessed the activity of sequential EGFR TKI regimens. These studies support the hypothesis that sequential use of EGFR TKIs represents a viable treatment option in 'real-world' clinical practice.

What could the future hold for treatment sequencing in cancer medicine? An interview with Angela Märten

Professor Angela Märten speaks to Rachel Jenkins, Commissioning Editor Angela Märten earned her PhD at Humboldt University of Berlin, Germany, in 2000, after working for several years as an oncology nurse. Upon completion of her PhD, she assumed responsibility for Phase I trials and translational research for the University Hospital of Bonn, Germany. In 2002, the University Hospital of Bonn appointed her as Assistant Professor for Experimental Haematology and Oncology. In 2003, she accepted a new position at the University of Heidelberg, Germany, heading the Immunotherapeutic Group and the Oncology Trial Department. The University of Heidelberg appointed her as Associate Professor in 2006 while she completed her Master of Sciences in Clinical Research in 2008. Professor Märten has been principal investigator of several clinical trials and has published more than 100 papers, with a particular focus on pancreatic carcinoma and lung cancer. She joined Boehringer Ingelheim in 2009, where she built up the German Medical Affairs Oncology team, before joining the Global Afatinib team in 2013. She is currently Global Senior Medical Advisor, Therapeutic Area of Oncology at Boehringer Ingelheim.

Second-generation EGFR and ErbB tyrosine kinase inhibitors as first-line treatments for non-small cell lung cancer

The discovery that mutations in the EGFR gene are present in up to 50% of patients with lung adenocarcinoma, and the development of highly efficacious EGFR tyrosine kinase inhibitors (TKIs), has revolutionized the way this common malignancy is treated. Three generations of EGFR TKIs are now approved for use in EGFR mutation-positive non-small cell lung cancer (NSCLC); the first-generation agents erlotinib, gefitinib, and icotinib; the second-generation ErbB family blockers afatinib and dacomitinib; and most recently, osimertinib, a third-generation EGFR TKI. The second-generation agents have demonstrated impressive efficacy relative to both standard platinum-based chemotherapy and first-generation EGFR TKIs, significantly improving response and progression-free and overall survival. Data from real-world studies suggest that afatinib is as effective and well tolerated in routine clinical practice as it is in clinical studies and is effective in patients with certain uncommon EGFR mutations, patients with brain metastases, and older patients. Few real-world data are available for dacomitinib in the first-line setting. Afatinib and dacomitinib have similar safety profiles, with acne/skin dryzness, diarrhea, stomatitis, and paronychia the most common adverse events (AEs) reported in clinical and real-world studies. Numerous studies have shown that tolerability-guided dose reductions can help manage afatinib-related AEs without reducing efficacy. As the number of therapeutic options for advanced NSCLC increases, the optimal choice for first-line treatment will be determined by considering patient factors such as the presence of brain metastases, the type of EGFR mutation, tolerability, and subsequent therapy options for long-term treatment.

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

Introduction: Epidermal growth factor receptor (EGFR) mutations are well-described drivers of non-small cell lung cancer (NSCLC) and EGFR tyrosine kinase inhibitors (TKIs) have become key components of the NSCLC front-line treatment landscape. Tumors inevitably develop resistance to these agents, and development efforts continue to focus on identifying mechanisms of resistance and drugs to target these mechanisms. Areas covered: With several EGFR TKIs approved for use in the first-line or in later-line settings, an understanding of the efficacy and safety of these inhibitors in various populations is warranted. Furthermore, given the frequent emergence of drug resistance in NSCLC, examination of tumor tissue throughout the disease course provides the opportunity to select treatments based on the tumor's mutation profile. Here, we discuss: key efficacy and safety findings for approved and investigational EGFR TKIs; known mechanisms of resistance, particularly the T790M acquired EGFR mutation; and recent advances in EGFR mutational testing that may facilitate less invasive tissue testing and guide treatment selection. Expert commentary: The expanding armamentarium of EGFR TKIs, improvements in the understanding of resistance mechanisms and technological developments in the molecular analysis of tumors may help render EGFR mutation-positive NSCLC a chronic disease in many patients by facilitating optimal sequential therapy.

Real-world study of afatinib in first-line or re-challenge settings for patients with EGFR mutant non-small cell lung cancer

Afatinib, a second-generation epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) for mutant non-small cell lung cancer (NSCLC), was approved in Japan in 2014. This study evaluated clinical outcomes of afatinib in real-world practice. Medical records of patients who received afatinib for advanced EGFR-mutant NSCLC were retrospectively reviewed. In total, 128 patients were analyzed. Seventy-six patients received afatinib as the first-line setting and 52 as the re-challenge setting (i.e., after failure of prior first-generation TKI). There was no difference in patient characteristics, such as age, sex, and PS, between the first-line and the re-challenge settings. In the first-line setting, the median progression-free survival (PFS) was 17.8 months (95% confidence interval [CI] 13.7-21.5 months). The overall survival (OS) was 39.5 months (95% CI 34.4- not reached). The response rate (RR) was 64.4%. Subset analysis indicated that patients with dose reduction showed longer PFS than those without dose reduction (18.5 months versus 7.9 months) (P = 0.016). In the re-challenge setting, the median PFS was 8.0 months (95% CI 4.9-9.5 months). The RR was 25%. Most common adverse events leading to dose modification or treatment discontinuation included diarrhea, paronychia, and oral mucositis in both settings. Interstitial lung disease occurred in 5.4% (7/128). In the real-world practice in Japan, afatinib showed comparable or better efficacy compared with that shown in previous clinical trials in both the first-line and the re-challenge settings.

Duration of treatment among patients prescribed afatinib or erlotinib as first-line therapy for EGFR mutation-positive non-small-cell lung cancer in the USA

Aim: Evaluate duration of therapy among patients treated with afatinib or erlotinib as first-line therapy for non-small-cell lung cancer (NSCLC). Materials & methods: NSCLC patients initiating afatinib or erlotinib between 2014 and 2017 were identified in three large claims databases in the USA. Propensity score matching was conducted to compare the duration of treatment between patients by treatment. Results: Patients prescribed afatinib had a significantly longer median duration of treatment compared with those prescribed erlotinib (12.1 vs 9.9 months; p = 0.035) and experienced a 14% reduction in risk of discontinuing therapy (adjusted hazard ratio: 0.86; CI: 0.75–0.99). Conclusion: First-line treatment duration in a real-world setting was significantly longer for patients prescribed afatinib compared with erlotinib.

Clinical analysis of EGFR-positive non-small cell lung cancer patients treated with first-line afatinib: A Nagano Lung Cancer Research Group

BACKGROUND

In the LUX-Lung 3 and LUX-Lung 6 trials, afatinib improved overall survival in previously untreated patients with EGFR 19del mutated non-small cell lung cancer (NSCLC) compared to chemotherapy. The appropriate management of adverse events and dose reduction of afatinib are important for EGFR-positive NSCLC patients. We conducted a retrospective and observational study of patients treated with first-line afatinib for EGFR-positive NSCLC in Nagano prefecture, Japan, focusing on efficacy and toxicities.

METHODS

We retrospectively collected the medical records of NSCLC patients initially treated with afatinib between May 2014 and March 2018.

RESULTS

A total of 62 patients with a median age of 67 years and a median body surface area (BSA) of 1.57 m2 were included. The overall response rate was 87.7% and median progression-free survival (PFS) was 15.7 months. The median PFS was similar between standard initial dose (40 mg) and reduced initial doses (30 and 20 mg) (15.7 vs. 14.2 months; P = 0.978). The frequency of dose reduction and the discontinuation rate in the 40 mg daily dose group was higher in patients with BSA < 1.58 m2 (100%) compared to BSA ≥ 1.58 m2 (68.2%) (P = 0.014). The frequency of diarrhea was higher in patients with BSA < 1.58 m2 (93.5%) compared to BSA ≥ 1.58 m2 (71.0%) (P = 0.02).

CONCLUSION

In real-world clinical practice, first-line afatinib was well managed and was equally as effective as in previous clinical trials of EGFR-positive NSCLC. BSA is considered a predictive marker for appropriate afatinib dose reduction.

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.

First-line afatinib for the treatment of EGFR mutation-positive non-small-cell lung cancer in the 'real-world' clinical setting

Afatinib is an ErbB family blocker that is approved for the treatment of epidermal growth factor receptor (EGFR) mutation-positive non-small-cell lung cancer (NSCLC). Pivotal randomized clinical studies demonstrated that afatinib significantly prolonged progression-free survival compared with platinum-based chemotherapy (LUX-Lung 3, LUX-Lung 6), and with gefitinib (LUX-Lung 7), with manageable side effects. However, these results were derived from controlled studies conducted in selected patients and are not necessarily representative of real-world use of afatinib. To gain a broader understanding of the effectiveness and safety of first-line afatinib, we have undertaken a literature review of real-world studies that have assessed its use in a variety of patient populations. We focused on patients with uncommon EGFR mutations, brain metastases, or those of advanced age, as these patients are often excluded from clinical studies but are regularly seen in routine clinical practice. The available real-world studies suggest that afatinib has clinical activity, and is tolerable, in diverse patient populations in an everyday clinical practice setting. Moreover, consistent with LUX-Lung 7, several real-world comparative studies indicate that afatinib might confer better efficacy than first-generation EGFR tyrosine kinase inhibitors. Tolerability-guided dose adjustment, undertaken in 21-68% of patients in clinical practice, did not appear to reduce the efficacy of afatinib. Taken together, these findings provide further support for the use of afatinib as a treatment option in patients with EGFR mutation-positive NSCLC.

Sequencing of therapy following first-line afatinib in patients with EGFR mutation-positive non-small cell lung cancer

OBJECTIVES

With the availability of several epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs), sequential therapy could potentially render EGFR mutation-positive non-small cell lung cancer a chronic disease in some patients. In this retrospective analysis of EGFR mutation-positive (Del19/L858R) patients receiving first-line afatinib in LUX-Lung 3, 6, and 7, we assessed uptake of, and outcomes following, subsequent therapies including the third-generation EGFR TKI, osimertinib.

METHODS

Post-progression therapy data were prospectively collected during follow-up. Molecular testing of tumours at progression/discontinuation of afatinib was not mandatory. Duration of subsequent therapies, and survival following osimertinib, were calculated with Kaplan-Meier estimates.

RESULTS

Among 553 patients who discontinued first-line afatinib, second-, third- and fourth-line therapy was administered in 394 (71%), 265 (48%), and 156 (28%) patients. The most common post-progression therapy was platinum-based chemotherapy (46%). Thirty-seven patients received subsequent osimertinib, 10 as second-line treatment. Median progression-free survival on afatinib in these 37 patients was 21.9 months. Median duration of osimertinib therapy was 20.2 months; median overall survival was not reached after a median follow-up of 4.7 years.

CONCLUSIONS

Most patients treated with first-line afatinib received subsequent therapy. Although limited by sample size, enrichment, and a retrospective nature, data from patients who received sequential afatinib and osimertinib are encouraging, warranting further investigation.

Re-challenge of afatinib after 1st generation EGFR-TKI failure in patients with previously treated non-small cell lung cancer harboring EGFR mutation

BACKGROUND

Re-challenge of erlotinib after gefitinib failure is reported to yield some benefit in patients with non-small cell lung cancer (NSCLC) harboring epidermal growth factor receptor (EGFR) mutation. However, little is known about the re-challenge of afatinib after 1st generate on EGFR tyrosine kinase inhibitor (TKI) failure.

METHODS

From May 2015 to August 2018, 62 patients with advanced NSCLC harboring sensitive EGFR mutation received afatinib after gefitinib and/or erlotinib failure at our institution was included in our retrospective study.

RESULTS

The overall response rate (ORR) and disease control rate (DCR) of afatinib as re-challenge were 17.0% and 79.2%, respectively. The median time on treatment of 1st generation EGFR-TKI (1st TKI) was 14 months. By multivariate analysis, smoking, performance status (PS), and time on treatment of 1st TKI with more than 10 months were confirmed to be independent prognostic factors predicting a worse progression-free survival (PFS), and significant prognostic markers for overall survival (OS) were PS and time on treatment of 1st TKI with more than 10 months, especially in patients with exon 19 deletion.

CONCLUSIONS

Re-challenge of afatinib was identified as one of the therapeutic options after 1st TKI failure in the patients with advanced NSCLC harboring EGFR mutation when the time of treatment by prior 1st TKI is more than 10 months.

Liquid-Biopsy-Based Identification of EGFR T790M Mutation-Mediated Resistance to Afatinib Treatment in Patients with Advanced EGFR Mutation-Positive NSCLC, and Subsequent Response to Osimertinib

BACKGROUND

Acquired epidermal growth factor receptor (EGFR) T790M mutation is the primary resistance mechanism to first-generation EGFR tyrosine kinase inhibitors (TKIs) used in advanced, EGFR mutation-positive non-small-cell lung cancer (NSCLC). Available data, predominantly in Asian patients, suggest that this mutation is also the major cause of resistance to the irreversible ErbB family blocker, afatinib. For EGFR T790M-positive patients who progress on EGFR TKI therapy, osimertinib is an effective treatment option. However, data on osimertinib use after afatinib are, to date, scarce.

OBJECTIVE

To identify the prevalence of EGFR T790M mutations in predominantly Caucasian patients with stage IV EGFR mutation-positive NSCLC who progressed on afatinib, and to investigate the subsequent response to osimertinib.

PATIENTS AND METHODS

In this single-center, retrospective analysis, EGFR T790M mutation status after afatinib failure was assessed using liquid biopsy and tissue rebiopsy. EGFR T790M-positive patients subsequently received osimertinib.

RESULTS

Sixty-seven patients received afatinib in the first-, second-, or third-line (80.6%, 14.9%, and 4.5%, respectively). After afatinib failure, the T790M mutation was identified in 49 patients (73.1%). Liquid biopsy and tissue rebiopsy were concordant in 79.4% of cases. All patients with T790M-positive tumors received osimertinib (73.5% after first-line afatinib); 37 (75.5%) of these had an objective response (complete response: 22.4%; partial response: 53.1%). Response rate was independent of T790M copy number.

CONCLUSION

EGFR T790M mutation is a major mechanism of acquired resistance to afatinib. Osimertinib confers high response rates after afatinib failure in EGFR T790M-positive patients and its use in sequence potentially allows extended chemotherapy-free treatment.

First- and Second-Generation EGFR-TKIs Are All Replaced to Osimertinib in Chemo-Naive EGFR Mutation-Positive Non-Small Cell Lung Cancer?

Activating mutations of the epidermal growth factor receptor gene (EGFR) are a driving force for some lung adenocarcinomas. Several randomized phase III studies have revealed that treatment with first- or second-generation EGFR tyrosine kinase inhibitors (TKIs) results in an improved progression-free survival (PFS) compared to standard chemotherapy in chemonaive patients with advanced non⁻small cell lung cancer (NSCLC), selected based on the presence of EGFR mutations. Patients treated with second-generation EGFR-TKIs have also shown an improved PFS relative to those treated with first-generation EGRF-TKIs. Osimertinib is a third-generation EGFR-TKI that still irreversibly inhibits the activity of EGFR after it has acquired the secondary T790M mutation that confers resistance to first- and second-generation drugs. Its efficacy has been validated for patients whose tumors have developed T790M-mediated resistance, as well as for first-line treatment of those patients with EGFR mutation⁻positive NSCLC. Although there are five EGFR-TKIs (gefitinib, erlotinib, afatinib, dacomitinib, and osimertinib) currently available for the treatment of EGFR-mutated lung cancer, the optimal sequence for administration of these drugs remains to be determined. In this review, we addressed this issue with regard to maximizing the duration of the EGFR-TKI treatment.

Prospective exosome-focused translational research for afatinib study of non-small cell lung cancer patients expressing EGFR (EXTRA study)

Patients with EGFR‐mutated non‐small cell lung cancer (NSCLC) exhibit resistance to EGFR‐tyrosine kinase inhibitors (TKIs) within 9–14 months of therapy. Recently, EGFR‐mutated NSCLC has demonstrated the potential for heterogeneity; therefore, the manner of clonal heterogeneity may impact the duration of progression‐free and overall survival and other parameters affecting EGFR‐TKI treatment efficacy. However no predictive biomarker of these favorable treatment efficacies has been identified to date. The exosome‐focused translational research for afatinib (EXTRA) study aims to identify a novel predictive biomarker and a resistance marker for afatinib by analyzing data from association studies of the clinical efficacy of afatinib and four “OMICs” (genomics, proteomics, epigenomics, and metabolomics) using peripheral blood from patients treated with afatinib. This study aims to: (i) conduct comprehensive multi‐OMIC analyses in a prospective clinical trial, and (ii) focus on both sera/plasma and exosome as a source for OMIC analyses to identify a novel predictor of the efficacy of a specific drug. To eliminate the carryover bias of prior treatment, systemic treatment‐naïve patients were enrolled. The candidates to be screened for biomarkers comprise a discovery cohort of 60 patients and an independent validation cohort of 40 patients. The EXTRA study is the first trial to screen novel biomarkers of longer treatment efficacy of EGFR‐TKIs using four‐OMICs analyses, focusing on both “naked or free” molecules and “capsulated” exosomal components in serially collected peripheral blood.

Tumor clonality and resistance mechanisms in EGFR mutation-positive non-small-cell lung cancer: implications for therapeutic sequencing

While the development of EGFR-targeted tyrosine kinase inhibitors (TKIs) has revolutionized treatment of EGFR mutation-positive non-small-cell lung cancer, acquired resistance to therapy is inevitable, reflecting tumor evolution. Recent studies show that EGFR mutation-positive non-small-cell lung cancer is highly heterogeneous at the cellular level, facilitating clonal expansion of resistant tumors via multiple molecular mechanisms. Here, we review the mechanistic differences between first-, second- and third-generation EGFR-targeted TKIs and speculate how these features could explain differences in clinical activity between these agents from a clonal evolution perspective. We hypothesize that the molecular dissection of tumor resistance mechanisms will facilitate optimal sequential use of EGFR TKIs in individual patients, thus maximizing the duration of chemotherapy-free treatment and survival benefit.