Atrial fibrillation symptom reduction and improved quality of life following the hybrid convergent procedure: a CONVERGE trial subanalysis.

Background: CONVERGE was a prospective, multicenter, randomized controlled trial that evaluated the safety of Hybrid Atrial Fibrillation Convergent (HC) and compared its effectiveness to endocardial catheter ablation (CA) for the treatment of persistent atrial fibrillation (PersAF) and longstanding PersAF (LSPAF). In 2020, we reported that CONVERGE met its primary safety and effectiveness endpoints. The primary objective of the present study is to report CONVERGE trial results for quality of life (QOL) and Class I/III anti-arrhythmic drug (AAD) utilization following HC. Methods: Eligible patients had drug-refractory symptomatic PersAF or LSPAF and a left atrium diameter ≤6.0 cm. Enrolled patients were randomized 2:1 to receive HC or CA. Atrial Fibrillation Severity Scale (AFSS) and the 36-Item Short Form Health Survey (SF-36) were assessed at baseline and 12 months; statistical comparison was performed using paired t-tests. AAD utilization at baseline through 12 and 18 months post-procedure was evaluated; statistical comparison was performed using McNemar's tests. Results: A total of 153 patients were treated with either HC (n=102) or CA (n=51). Of the 102 HC patients, 38 had LSPAF. AFSS and SF-36 Mental and Physical Component scores were significantly improved at 12 months versus baseline with HC overall and for the subset of LSPAF patients treated with either HC or CA. The proportion of HC patients (n=102) who used Class I /III AADs at 12 and 18 months was significantly less (33.3% and 36.3%, respectively) than baseline (84.3%; P<0.001). In LSPAF patients who underwent HC (n=38), AADs use was 29.0% through 18 months follow-up versus 71.1% at baseline (P<0.001). Conclusions: HC reduced AF symptoms, significantly improved QOL, and reduced AAD use in patients with PersAF and LSPAF. ClinicalTrialsgov Identifier: NCT01984346.

Pegargiminase Plus First-Line Chemotherapy in Patients With Nonepithelioid Pleural Mesothelioma: The ATOMIC-Meso Randomized Clinical Trial.

Importance: Arginine deprivation using ADI-PEG20 (pegargiminase) combined with chemotherapy is untested in a randomized study among patients with cancer. ATOMIC-Meso (ADI-PEG20 Targeting of Malignancies Induces Cytotoxicity-Mesothelioma) is a pivotal trial comparing standard first-line chemotherapy plus pegargiminase or placebo in patients with nonepithelioid pleural mesothelioma. Objective: To determine the effect of pegargiminase-based chemotherapy on survival in nonepithelioid pleural mesothelioma, an arginine-auxotrophic tumor. Design, Setting, and Participants: This was a phase 2-3, double-blind randomized clinical trial conducted at 43 centers in 5 countries that included patients with chemotherapy-naive nonepithelioid pleural mesothelioma from August 1, 2017, to August 15, 2021, with at least 12 months' follow-up. Final follow-up was on August 15, 2022. Data analysis was performed from March 2018 to June 2023. Intervention: Patients were randomly assigned (1:1) to receive weekly intramuscular pegargiminase (36.8 mg/m2) or placebo. All patients received intravenous pemetrexed (500 mg/m2) and platinum (75-mg/m2 cisplatin or carboplatin area under the curve 5) chemotherapy every 3 weeks up to 6 cycles. Pegargiminase or placebo was continued until progression, toxicity, or 24 months. Main Outcomes and Measures: The primary end point was overall survival, and secondary end points were progression-free survival and safety. Response rate by blinded independent central review was assessed in the phase 2 portion only. Results: Among 249 randomized patients (mean [SD] age, 69.5 [7.9] years; 43 female individuals [17.3%] and 206 male individuals [82.7%]), all were included in the analysis. The median overall survival was 9.3 months (95% CI, 7.9-11.8 months) with pegargiminase-chemotherapy as compared with 7.7 months (95% CI, 6.1-9.5 months) with placebo-chemotherapy (hazard ratio [HR] for death, 0.71; 95% CI, 0.55-0.93; P = .02). The median progression-free survival was 6.2 months (95% CI, 5.8-7.4 months) with pegargiminase-chemotherapy as compared with 5.6 months (95% CI, 4.1-5.9 months) with placebo-chemotherapy (HR, 0.65; 95% CI, 0.46-0.90; P = .02). Grade 3 to 4 adverse events with pegargiminase occurred in 36 patients (28.8%) and with placebo in 21 patients (16.9%); drug hypersensitivity and skin reactions occurred in the experimental arm in 3 patients (2.4%) and 2 patients (1.6%), respectively, and none in the placebo arm. Rates of poststudy treatments were comparable in both arms (57 patients [45.6%] with pegargiminase vs 58 patients [46.8%] with placebo). Conclusions and Relevance: In this randomized clinical trial of arginine depletion with pegargiminase plus chemotherapy, survival was extended beyond standard chemotherapy with a favorable safety profile in patients with nonepithelioid pleural mesothelioma. Pegargiminase-based chemotherapy as a novel antimetabolite strategy for mesothelioma validates wider clinical testing in oncology. Trial Registration: ClinicalTrials.gov Identifier: NCT02709512.

PD-1-expressing macrophages and CD8 T cells are independent predictors of clinical benefit from PD-1 inhibition in advanced mesothelioma.

BACKGROUND: Few tissue biomarkers exist to date that could enrich patient with cancer populations to benefit from immune checkpoint blockade by programmed cell death protein 1/ligand-1 (PD-/L-1) inhibitors. PD-L1 expression has value in this context in some tumor types but is an imperfect predictor of clinical benefit. In malignant pleural mesothelioma, PD-L1 expression is not predictive of the benefit from PD-1 blockade. We aimed to identify novel markers in malignant pleural mesothelioma to select patients better. METHODS: We performed a multiplex-immune histochemistry analysis of tumor samples from the phase III PROMISE-meso study, which randomized 144 pretreated patients to receive either pembrolizumab or standard second-line chemotherapy. Our panel focused on CD8+T cell, CD68+macrophages, and the expression of PD-1 and PD-L1 on these and cancer cells. We analyzed single and double positive cells within cancer tissues (infiltrating immune cells) and in the stroma. In addition, we performed cell neighborhood analysis. The cell counts were compared with clinical outcomes, including responses, progression-free and overall survivals. RESULTS: We confirmed the absence of predictive value for PD-L1 in this cohort of patients. Furthermore, total CD8 T cells, CD68+macrophages, or inflammatory subtypes (desert, excluded, inflamed) did not predict outcomes. In contrast, PD-1-expressing CD8+T cells (exhausted T cells) and PD-1-expressing CD68+macrophages were both independent predictors of progression-free survival benefit from pembrolizumab. Patients with tumors simultaneously harboring PD1+T cells and PD-1+macrophages benefited the most from immune therapy. CONCLUSION: We analyzed a large cohort of patients within a phase III study and found that not only PD-1+CD8 T cells but also PD-1+CD68+ macrophages are predictive. This data provides evidence for the first time for the existence of PD-1+macrophages in mesothelioma and their clinical relevance for immune checkpoint blockade.

Thymic epithelial tumour radiotherapy in the UK: A survey of current clinical practice.

Significant variation in treatment centre setup and radiotherapy practice for thymic epithelial tumours (TET) was identified through a comprehensive survey of current UK Clinical (Radiation) Oncology practice. Multi-centre collaboration and wider TET specific multidisciplinary team meetings are needed and will be essential for developing expertise in TET radiotherapy.

A case of malignant mesothelioma in a young patient with childhood leukaemia who had received total body irradiation.

This case report explores a 34-year-old male diagnosed with mesothelioma who had no known risk factors. The patient initially was treated for empyema with antibiotics but later represented to hospital with worsening symptoms. He underwent a surgical Video-assisted thoracoscopic surgery procedure and lung biopsy, which revealed a diagnosis of mesothelioma. The young age of the patient as well as absence of significant risk factors for mesothelioma made the diagnosis unexpected. The patient had total body irradiation (TBI) therapy for leukaemia as a child, which increases the risk of developing cancer. However, there are limited studies exploring the risk of pleural mesothelioma post-TBI. Young patients who represent to hospital, with limited response to initial treatment, and suspicious radiological features should be considered for lung biopsy to reduce the risk of a missed diagnosis. Patients with a background of TBI should also be considered for follow-up to monitor for any subsequent malignancy.

A prognostic score for patients with malignant pleural mesothelioma (MPM) receiving second-line immunotherapy or chemotherapy in the ETOP 9-15 PROMISE-meso phase III trial.

INTRODUCTION: Clinical and laboratory parameters associated with response for patients with advanced pre-treated malignant pleural mesothelioma (MPM) are lacking. We aimed to identify prognostic and predictive markers among patients with relapsed MPM who were randomised into the ETOP 9-15 PROMISE-meso phase III trial, evaluating pembrolizumab and chemotherapy. METHODS: Baseline clinical and laboratory parameters were investigated for prognostic or predictive value on progression-free survival (PFS) and overall survival (OS) in a retrospective analysis, based on the full cohort of 144 MPM patients. These consisted of immune-inflammatory indexes (neutrophil-lymphocyte ratio [NLR], systemic immune-inflammatory index [SII], lactate dehydrogenase [LDH]) along with other already known prognostic baseline characteristics and laboratory values. Cut-offs were chosen independently of outcome. Based on Cox multivariable analysis for PFS in the whole cohort, a risk factor model was built to illustrate the prognostic stratification of patients by the combination of the derived independent prognostic factors, taking into account the EORTC score, a validated prognostic score in MPM. All models were stratified by histology and adjusted by treatment. RESULTS: In the stratified multivariable analysis in the whole cohort, high SII (hazard ratio (HR) 2.06; 95%CI 1.39-3.05) and low haemoglobin (HR 1.62; 95%CI 1.06-2.50) were associated with worse PFS. Based on these two prognostic factors, a mesothelioma risk score (MRS) was constructed with three PFS risk prognosis categories: favourable, intermediate and poor with 0, 1 and 2 risk factors, respectively (corresponding percent of cohort: 24%, 34% and 42% and median PFS: 5.8, 4.2 and 2.1 months). The derived MRS stratified the prognosis for PFS and OS, overall and within each of the EORTC groups. No significant predictors of treatment benefit were identified. CONCLUSIONS: The proposed MRS is prognostic of patient outcome and it fine-tunes the prognosis of patients with pre-treated MPM alone or when used with the already established EORTC score.

Publisher Correction: The National Lung Matrix Trial of personalized therapy in lung cancer.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

The National Lung Matrix Trial of personalized therapy in lung cancer.

The majority of targeted therapies for non-small-cell lung cancer (NSCLC) are directed against oncogenic drivers that are more prevalent in patients with light exposure to tobacco smoke1-3. As this group represents around 20% of all patients with lung cancer, the discovery of stratified medicine options for tobacco-associated NSCLC is a high priority. Umbrella trials seek to streamline the investigation of genotype-based treatments by screening tumours for multiple genomic alterations and triaging patients to one of several genotype-matched therapeutic agents. Here we report the current outcomes of 19 drug-biomarker cohorts from the ongoing National Lung Matrix Trial, the largest umbrella trial in NSCLC. We use next-generation sequencing to match patients to appropriate targeted therapies on the basis of their tumour genotype. The Bayesian trial design enables outcome data from open cohorts that are still recruiting to be reported alongside data from closed cohorts. Of the 5,467 patients that were screened, 2,007 were molecularly eligible for entry into the trial, and 302 entered the trial to receive genotype-matched therapy-including 14 that re-registered to the trial for a sequential trial drug. Despite pre-clinical data supporting the drug-biomarker combinations, current evidence shows that a limited number of combinations demonstrate clinically relevant benefits, which remain concentrated in patients with lung cancers that are associated with minimal exposure to tobacco smoke.

Genomic evidence supports a clonal diaspora model for metastases of esophageal adenocarcinoma.

The poor outcomes in esophageal adenocarcinoma (EAC) prompted us to interrogate the pattern and timing of metastatic spread. Whole-genome sequencing and phylogenetic analysis of 388 samples across 18 individuals with EAC showed, in 90% of patients, that multiple subclones from the primary tumor spread very rapidly from the primary site to form multiple metastases, including lymph nodes and distant tissues-a mode of dissemination that we term 'clonal diaspora'. Metastatic subclones at autopsy were present in tissue and blood samples from earlier time points. These findings have implications for our understanding and clinical evaluation of EAC.

A hypercoagulable state leading to venous limb gangrene associated with occult lung adenocarcinoma.

We report a case of lung adenocarcinoma-associated hypercoagulability leading to venous limb gangrene, managed successfully with argatroban and then dabigatran. Use of idarucizumab permitted diagnostic investigations, leading to targeted antineoplastic therapy with crizotinib, surgical resection with curative intent, and continued survival over 2 years after the index event.

Prophylactic Irradiation of Tracts in Patients With Malignant Pleural Mesothelioma: An Open-Label, Multicenter, Phase III Randomized Trial.

PURPOSE: Prophylactic irradiation to the chest wall after diagnostic or therapeutic procedures in patients with malignant pleural mesothelioma (MPM) has been a widespread practice across Europe, although the efficacy of this treatment is uncertain. In this study, we aimed to determine the efficacy of prophylactic radiotherapy in reducing the incidence of chest wall metastases (CWM) after a procedure in MPM. METHODS: After undergoing a chest wall procedure, patients with MPM were randomly assigned to receive prophylactic radiotherapy (within 42 days of the procedure) or no radiotherapy. Open thoracotomies, needle biopsies, and indwelling pleural catheters were excluded. Prophylactic radiotherapy was delivered at a dose of 21 Gy in three fractions over three consecutive working days, using a single electron field adapted to maximize coverage of the tract from skin surface to pleura. The primary outcome was the incidence of CWM within 6 months from random assignment, assessed in the intention-to-treat population. Stratification factors included epithelioid histology and intention to give chemotherapy. RESULTS: Between July 30, 2012, and December 12, 2015, 375 patients were recruited from 54 centers and randomly assigned to receive prophylactic radiotherapy (n = 186) or no prophylactic radiotherapy (n = 189). Participants were well matched at baseline. No significant difference was seen in the incidence of CWM at 6 months between the prophylactic radiotherapy and no radiotherapy groups (no. [%]: 6 [3.2] v 10 [5.3], respectively; odds ratio, 0.60; 95% CI, 0.17 to 1.86; P = .44). Skin toxicity was the most common radiotherapy-related adverse event in the prophylactic radiotherapy group, with 96 patients (51.6%) receiving grade 1; 19 (10.2%), grade 2; and 1 (0.5%) grade 3 radiation dermatitis (Common Terminology Criteria for Adverse Events, version 4.0). CONCLUSION: There is no role for the routine use of prophylactic irradiation to chest wall procedure sites in patients with MPM.

Maintenance Defactinib Versus Placebo After First-Line Chemotherapy in Patients With Merlin-Stratified Pleural Mesothelioma: COMMAND-A Double-Blind, Randomized, Phase II Study.

PURPOSE: Inhibition of focal adhesion kinase has been shown to selectively kill mesothelioma cells that express low levels of moesin-ezrin-radixin-like protein (merlin). On this basis, we designed a randomized, phase II trial to investigate whether defactinib as maintenance therapy after standard first-line chemotherapy could improve progression-free survival (PFS) in patients with malignant pleural mesothelioma (MPM). METHODS: This global, double-blind, randomized, placebo-controlled trial was conducted in patients with advanced MPM and disease control after at least four cycles of first-line chemotherapy. Patients were stratified for merlin and then randomly assigned (in a 1:1 fashion) to receive either oral defactinib or placebo until disease progression, unacceptable toxicity, or withdrawal occurred. The coprimary end points were PFS and overall survival (OS). Quality of life (QoL) was assessed using the Lung Cancer Symptom Scale for Mesothelioma tool. RESULTS: Three hundred forty-four patients were randomly assigned to receive either defactinib (n = 173) or placebo (n = 171). The median PFS was 4.1 months (95% CI, 2.9 to 5.6 months) for defactinib versus 4.0 months (95% CI, 2.9 to 4.2 months) for placebo. The median OS was 12.7 months (95% CI, 9.1 to 21 months) for defactinib versus 13.6 months (95% CI, 9.6 to 21.2 months) for placebo (hazard ratio, 1.0; 95% CI, 0.7 to 1.4). Although shorter survival for both defactinib- and placebo-treated patients was observed, in the patients who had merlin-low MPM compared with the patients who had merlin-high MPM, there were no statistical differences in response rate, PFS, OS, or QoL between the treatment groups. The most common grade 3 or worse adverse events were nausea, diarrhea, fatigue, dyspnea, and decreased appetite. CONCLUSION: Neither PFS nor OS was improved by defactinib after first-line chemotherapy in patients with merlin-low MPM. Defactinib cannot be recommended as maintenance therapy for advanced MPM.

Six key topics informal carers of patients with breathlessness in advanced disease want to learn about and why: MRC phase I study to inform an educational intervention.

INTRODUCTION: Breathlessness is a common symptom of advanced disease placing a huge burden on patients, health systems and informal carers (families and friends providing daily help and support). It causes distress and isolation. Carers provide complex personal, practical and emotional support yet often feel ill-prepared to care. They lack knowledge and confidence in their caring role. The need to educate carers and families about breathlessness is established, yet we lack robustly developed carer-targeted educational interventions to meet their needs. METHODS: We conducted a qualitative interview study with twenty five purposively-sampled patient-carer dyads living with breathlessness in advanced disease (half living with advanced cancer and half with advanced chronic obstructive pulmonary disease (COPD). We sought to identify carers' educational needs (including what they wanted to learn about) and explore differences by diagnostic group in order to inform an educational intervention for carers of patients with breathlessness in advanced disease. RESULTS: There was a strong desire among carers for an educational intervention on breathlessness. Six key topics emerged as salient for them: 1) understanding breathlessness, 2) managing anxiety, panic and breathlessness, 3) managing infections, 4) keeping active, 5) living positively and 6) knowing what to expect in the future. A cross-cutting theme was relationship management: there were tensions within dyads resulting from mismatched expectations related to most topics. Carers felt that knowledge-gains would not only help them to support the patient better, but also help them to manage their own frustrations, anxieties, and quality of life. Different drivers for education need were identified by diagnostic group, possibly related to differences in caring role duration and resulting impacts. CONCLUSION: Meeting the educational needs of carers requires robustly developed and evaluated interventions. This study provides the evidence-base for the content of an educational intervention for carers of patients with breathlessness in advanced disease.

Clinicians' Views of Educational Interventions for Carers of Patients With Breathlessness Due to Advanced Disease: Findings From an Online Survey.

CONTEXT: Carers' needs in advanced disease, and specifically in relation to breathlessness, are well evidenced. Publications on educational interventions for carers of patients with advanced disease that focus on symptoms are scarce and absent for breathlessness. OBJECTIVES: To establish current education provided by clinicians for carers of patients with breathlessness in advanced disease, views about educating carers about breathlessness, and relevant outcomes for a future randomized controlled trial of an educational intervention for carers. METHODS: An online survey was completed by 365 clinicians: medical, nursing, and allied health professionals from primary care, hospital, and hospice. Descriptive statistics summarized respondent characteristics and survey responses, and the Chi-squared test was applied. Content analysis of free-text comments was conducted. RESULTS: Most clinicians reported educating carers by educating patients at clinical contacts with patients. Carer involvement was largely an 'add-on'; an active carer education strategy, where all carers were invited to attend, was not currently apparent. Clinicians endorsed the importance of educating carers about breathlessness through increasing carer confidence and/or control, helping patients' better self-manage breathlessness and potentially reducing admissions. Joint education with patients, giving practical advice, and strategies for helping patients were advised. To inform a future trial, clinicians identified improvement in patient outcomes, particularly patient quality of life as very important in enhancing clinician adoption of an educational intervention for carers. CONCLUSION: This survey revealed an appetite among clinicians for an educational intervention for carers of patients with breathlessness in advanced disease and provided important insights to underpin a future Phase II randomized controlled trial.

Arginine Deprivation With Pegylated Arginine Deiminase in Patients With Argininosuccinate Synthetase 1-Deficient Malignant Pleural Mesothelioma: A Randomized Clinical Trial.

IMPORTANCE: Preclinical studies show that arginine deprivation is synthetically lethal in argininosuccinate synthetase 1 (ASS1)-negative cancers, including mesothelioma. The role of the arginine-lowering agent pegylated arginine deiminase (ADI-PEG20) has not been evaluated in a randomized and biomarker-driven study among patients with cancer. OBJECTIVE: To assess the clinical impact of arginine depletion in patients with ASS1-deficient malignant pleural mesothelioma. DESIGN, SETTING, AND PARTICIPANTS: A multicenter phase 2 randomized clinical trial, the Arginine Deiminase and Mesothelioma (ADAM) study, was conducted between March 2, 2011, and May 21, 2013, at 8 academic cancer centers. Immunohistochemical screening of 201 patients (2011-2013) identified 68 with advanced ASS1-deficient malignant pleural mesothelioma. INTERVENTIONS: Randomization 2:1 to arginine deprivation (ADI-PEG20, 36.8 mg/m2, weekly intramuscular) plus best supportive care (BSC) or BSC alone. MAIN OUTCOMES AND MEASURES: The primary end point was progression-free survival (PFS) assessed by modified Response Evaluation Criteria in Solid Tumors (RECIST) (target hazard ratio, 0.60). Secondary end points were overall survival (OS), tumor response rate, safety, and quality of life, analyzed by intention to treat. We measured plasma arginine and citrulline levels, anti-ADI-PEG20 antibody titer, ASS1 methylation status, and metabolic response by 18F-fluorodeoxyglucose positron-emission tomography. RESULTS: Median (range) follow-up in 68 adults (median [range] age, 66 [48-83] years; 19% female) was 38 (2.5-39) months. The PFS hazard ratio was 0.56 (95% CI, 0.33-0.96), with a median of 3.2 months in the ADI-PEG20 group vs 2.0 months in the BSC group (P = .03) (absolute risk, 18% vs 0% at 6 months). Best response at 4 months (modified RECIST) was stable disease: 12 of 23 (52%) in the ADI-PEG20 group vs 2 of 9 (22%) in the BSC group (P = .23). The OS curves crossed, so life expectancy was used: 15.7 months in the ADI-PEG20 group vs 12.1 months in the BSC group (difference of 3.6 [95% CI, -1.0 to 8.1] months; P = .13). The incidence of symptomatic adverse events of grade at least 3 was 11 of 44 (25%) in the ADI-PEG20 group vs 4 of 24 (17%) in the BSC group (P = .43), the most common being immune related, nonfebrile neutropenia, gastrointestinal events, and fatigue. Differential ASS1 gene-body methylation correlated with ASS1 immunohistochemistry, and longer arginine deprivation correlated with improved PFS. CONCLUSIONS AND RELEVANCE: In this trial, arginine deprivation with ADI-PEG20 improved PFS in patients with ASS1-deficient mesothelioma. Targeting arginine is safe and warrants further clinical investigation in arginine-dependent cancers. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01279967.

Sharing news of a lung cancer diagnosis with adult family members and friends: a qualitative study to inform a supportive intervention.

OBJECTIVE: Extensive research exists on breaking bad news by clinicians. This study examines perspectives of patients and those accompanying them at diagnosis-giving of subsequently sharing news of lung cancer with adult family/friends, and views of healthcare professionals, to inform development of a supportive intervention. METHODS: Qualitative interviews with 20 patients, 17 accompanying persons; focus groups and interviews with 27 healthcare professionals from four Thoracic Oncology Units. Intervention development workshops with 24 healthcare professionals and six service users with experience of sharing a cancer diagnosis. Framework thematic analysis. RESULTS: Patients and accompanying persons shared news of lung cancer whilst coming to terms with the diagnosis. They recalled general support from healthcare professionals but not support with sharing bad news. Six elements were identified providing a framework for a potential intervention: 1-people to be told, 2-information to be shared, 3-timing of sharing, 4-responsibility for sharing, 5-methods of telling others and 6-reactions of those told. CONCLUSION: This study identifies the challenge of sharing bad news and a potential framework to guide delivery of a supportive intervention tailored to individual needs of patients. PRACTICE IMPLICATIONS: The identified framework could extend the portfolio of guidance on communication in cancer and potentially in other life-limiting conditions.

Treatment approaches for EGFR-inhibitor-resistant patients with non-small-cell lung cancer.

Discovery of activating mutations in EGFR and their use as predictive biomarkers to tailor patient therapy with EGFR tyrosine kinase inhibitors (TKIs) has revolutionised treatment of patients with advanced EGFR-mutant non-small-cell lung cancer (NSCLC). At present, first-line treatment with EGFR TKIs (gefitinib, erlotinib, and afatinib) has been approved for patients harbouring exon 19 deletions or exon 21 (Leu858Arg) substitution EGFR mutations. These agents improve response rates, time to progression, and overall survival. Unfortunately, patients develop resistance, limiting patient benefit and posing a challenge to oncologists. Optimum treatment after progression is not clearly defined. A more detailed understanding of the biology of EGFR-mutant NSCLC and the mechanisms of resistance to targeted therapy mean that an era of treatment approaches based on rationally developed drugs or therapeutic strategies has begun. Combination approaches-eg, dual EGFR blockade-to overcome resistance have been trialled and seem to be promising but are potentially limited by toxicity. Third-generation EGFR-mutant-selective TKIs, such as AZD9291 or rociletininb, which target Thr790Met-mutant tumours, the most common mechanism of EGFR TKI resistance, have entered clinical trials, and exciting, albeit preliminary, efficacy data have been reported. In this Review, we summarise the scientific literature and evidence on therapy options after EGFR TKI treatment for patients with NSCLC, aiming to provide a guide to oncologists, and consider how to maximise therapeutic advances in outcomes in this rapidly advancing area.