Cerebrospinal fluid concentration of gefitinib and erlotinib in patients with non-small cell lung cancer

Preclinical evaluation of targeted therapies for central nervous system metastases

The central nervous system (CNS) represents a site of sanctuary for many metastatic tumors when systemic therapies that control the primary tumor cannot effectively penetrate intracranial lesions. Non-small cell lung cancers (NSCLCs) are the most likely of all neoplasms to metastasize to the brain, with up to 60% of patients developing CNS metastases during the disease process. Targeted therapies such as tyrosine kinase inhibitors (TKIs) have helped reduce lung cancer mortality but vary considerably in their capacity to control CNS metastases. The ability of these therapies to effectively target lesions in the CNS depends on several of their pharmacokinetic properties, including blood-brain barrier permeability, affinity for efflux transporters, and binding affinity for both plasma and brain tissue. Despite the existence of numerous preclinical models with which to characterize these properties, many targeted therapies have not been rigorously tested for CNS penetration during the discovery process, whereas some made it through preclinical testing despite poor brain penetration kinetics. Several TKIs have now been engineered with the characteristics of CNS-penetrant drugs, with clinical trials proving these efforts fruitful. This Review outlines the extent and variability of preclinical evidence for the efficacy of NSCLC-targeted therapies, which have been approved by the US Food and Drug Administration (FDA) or are in development, for treating CNS metastases, and how these data correlate with clinical outcomes.

Complete response in a lung adenocarcinoma with pleural metastases initially treated with gefitinib and switched to osimertinib after cerebral oligo-progression with unknown T790M mutation: a case report and review of literature

BACKGROUND

First- and second-generation anti-epithelial growth factor receptor tyrosine kinase inhibitors have shown great efficacy in the treatment of advanced adenocarcinoma with epithelial growth factor receptor mutations, but this efficacy is limited by certain resistance mechanisms, in particular the T790M mutation, which must be screened before second-line treatment with osimertinib is indicated. The search for this mutation is sometimes difficult, especially in cases of intracranial relapse, through this case report we attempt to discuss the possibility of initiating treatment with osimertinib despite an unknown T790M mutation in such situation.

CASE REPORT

We present the case of a 70-year-old Moroccan male patient diagnosed with non-small cell lung carcinoma initially metastatic to the pleura with an epithelial growth factor receptor mutation who received gefitinib in first line with a complete response, he subsequently presented with cerebral oligo-progression with extra cranial stability. The patient was started on osimertinib with unknown T790M status, as it was impossible to perform a cerebral biopsy, the evolution was characterized by a partial response followed by stereotactic radiotherapy then a complete response for 2 years.

CONCLUSION

We can discuss osimertinib as an option for patients with stage IV non-small cell lung cancer with brain oligo-progression on prior tyrosine kinase inhibitors and unknown T790M status, further studies are needed in this area.

Tyrosine kinase inhibitors in cancers: Treatment optimization - Part I

A multitude of TKI has been developed and approved targeting various oncogenetic alterations. While these have provided improvements in efficacy compared with conventional chemotherapies, resistance to targeted therapies occurs. Mutations in the kinase domain result in the inability of TKI to inactivate the protein kinase. Also, gene amplification, increased protein expression and downstream activation or bypassing of signalling pathways are commonly reported mechanisms of resistance. Improved understanding of mechanisms involved in TKI resistance has resulted in the development of new generations of targeted agents. In a race against time, the search for new, more potent and efficient drugs, and/or combinations of drugs, remains necessary as new resistance mechanisms to the latest generation of TKI emerge. This review examines the various generations of TKI approved to date and their common mechanisms of resistance, focusing on TKI targeting BCR-ABL, epidermal growth factor receptor, anaplastic lymphoma kinase and BRAF/MEK tyrosine kinases.

Treatment Advances in Lung Cancer with Leptomeningeal Metastasis

Leptomeningeal metastasis (LM) is a serious and often fatal complication in patients with advanced lung cancer, resulting in significant neurological deficits, decreased quality of life, and a poor prognosis. This article summarizes current research advances in treating lung cancer with meningeal metastases, discusses clinical challenges, and explores treatment strategies. Through an extensive review of relevant clinical trial reports and screening of recent conference abstracts, we collected clinical data on treating patients with lung cancer with meningeal metastases to provide an overview of the current research progress. Exciting progress has been made by focusing on specific mutations within lung cancer, including the use of EGFR tyrosine kinase inhibitors or inhibitors for anaplastic lymphoma kinase gene rearrangement, such as osimertinib, alectinib, and lorlatinib. These targeted therapies have shown impressive results in penetrating the central nervous system (CNS). Regarding whole-brain radiotherapy, there is currently some controversy among investigators regarding its effect on survival. Additionally, immune checkpoint inhibitors (ICIs) have demonstrated reliable clinical benefits due to their ability to retain anticancer activity in CNS metastases. Moreover, combination therapy shows promise in providing further treatment possibilities. Considerable progress has been made in the clinical research of lung cancer with LM. However, the sample size of prospective clinical trials investigating LM for lung cancer is still limited, with most reports being retrospective. Developing more effective management protocols for metastatic LM in lung cancer remains an ongoing challenge for the future.

Lazertinib versus Gefitinib as First-Line Treatment for EGFR-mutated Locally Advanced or Metastatic NSCLC: LASER301 Korean Subset

PURPOSE

This subgroup analysis of the Korean subset of patients in the phase 3 LASER301 trial evaluated the efficacy and safety of lazertinib versus gefitinib as first-line therapy for epidermal growth factor receptor mutated (EGFRm) non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

Patients with locally advanced or metastatic EGFRm NSCLC were randomized 1:1 to lazertinib (240 mg/day) or gefitinib (250 mg/day). The primary endpoint was investigator-assessed progression-free survival (PFS).

RESULTS

In total, 172 Korean patients were enrolled (lazertinib, n=87; gefitinib, n=85). Baseline characteristics were balanced between the treatment groups. One-third of patients had brain metastases (BM) at baseline. Median PFS was 20.8 months (95% confidence interval [CI], 16.7 to 26.1) for lazertinib and 9.6 months (95% CI, 8.2 to 12.3) for gefitinib (hazard ratio [HR], 0.41; 95% CI, 0.28 to 0.60). This was supported by PFS analysis based on blinded independent central review. Significant PFS benefit with lazertinib was consistently observed across predefined subgroups, including patients with BM (HR, 0.28; 95% CI, 0.15 to 0.53) and those with L858R mutations (HR, 0.36; 95% CI, 0.20 to 0.63). Lazertinib safety data were consistent with its previously reported safety profile. Common adverse events (AEs) in both groups included rash, pruritus, and diarrhoea. Numerically fewer severe AEs and severe treatment-related AEs occurred with lazertinib than gefitinib.

CONCLUSION

Consistent with results for the overall LASER301 population, this analysis showed significant PFS benefit with lazertinib versus gefitinib with comparable safety in Korean patients with untreated EGFRm NSCLC, supporting lazertinib as a new potential treatment option for this patient population.

Therapeutic role of EGFR - Tyrosine kinase inhibitors in non-small cell lung cancer with leptomeningeal metastasis

Leptomeningeal metastasis (LM) is a significant complication that advances fast and has a poor prognosis for patients with advanced non-small cell lung cancer (NSCLC) who have epidermal growth factor receptor (EGFR) mutations. Current therapies for LM are inconsistent and ineffective, and established techniques such as radiation, chemotherapy, and surgery continue to fall short of potential outcomes. Nonetheless, EGFR tyrosine kinase inhibitors (TKIs) exhibit potent anti-tumor activity and hold considerable promise for NSCLC patients with EGFR mutations. Thus, assessing EGFR-TKIs effectiveness in treating these central nervous system (CNS) problems is crucial. This review integrates current literature on the intracranial efficacy of EGFR-TKIs to explore the varying impacts of approved EGFR-TKIs in LM patients and the therapeutic possibilities presented by other EGFR-TKIs in development. To delineate the optimal clinical treatment strategy, further exploration is needed regarding the optimal sequencing of EGFR-TKIs and the selection of alternative therapy options following initial treatment failure with EGFR-TKIs.

Management strategies for intracranial progression in ALK-positive non-small cell lung cancer: a real-world cohort study

PURPOSE

ALK-positive NSCLC patients exhibit a particularly high propensity for the development of brain metastases. Current guidelines suggest transit to next-line therapy (SysTx) or local radiotherapy (RadTx) including whole-brain radiotherapy and radiosurgery. However, the clinical impact of these two strategies remains unclear.

METHODS

We conducted a retrospective analysis focusing on patients with stage IV ALK-positive NSCLC who underwent first-line ALK TKI treatment. Patients with intracranial progression may receive two different treatment strategies: SysTx and RadTx. Our objective was to investigate the outcomes associated with these two distinct treatment pathways.

RESULTS

A total 20 patients of ALK-positive NSCLC who received first-line ALK TKI therapy and subsequently developed intracranial progression were enrolled. About 55% of patients had brain metastasis initially. Nine patients (45%) were treated with crizotinib at first. Patients treated with crizotinib demonstrated a significantly shorter intracranial PFS1 (crizotinib: 8.27 months vs. others: 27.0 months, p = 0.006). Following intracranial progression, approximately 60% of patients transitioned to the next line of systemic treatment (SysTx), while the remaining 40% opted for local cranial radiotherapy (RadTx). Intriguingly, our analysis revealed no statistically significant difference in intracranial progression-free survival (PFS2) between these two distinct treatment strategies. (SysTx: 20.87 months vs. RadTx: 28.23 months, p = 0.461).

CONCLUSION

The intracranial progression-free survival showed no difference between the two strategies suggesting that both local radiotherapy and systemic therapy may be valid options. Individualized strategy, molecular analysis, and multidisciplinary conferences may all play a pivotal role in decision-making.

Central Nervous System Outcomes of Lazertinib Versus Gefitinib in EGFR-Mutated Advanced NSCLC: A LASER301 Subset Analysis

INTRODUCTION

Lazertinib, a third-generation mutant-selective EGFR tyrosine kinase inhibitor, improved progression-free survival compared with gefitinib in the phase 3 LASER301 study (ClinicalTrials.gov Identifier: NCT04248829). Here, we report the efficacy of lazertinib and gefitinib in patients with baseline central nervous system (CNS) metastases.

METHODS

Treatment-naive patients with EGFR-mutated advanced NSCLC were randomized one-to-one to lazertinib (240 mg/d) or gefitinib (250 mg/d). Patients with asymptomatic or stable CNS metastases were included if any planned radiation, surgery, or steroids were completed more than 2 weeks before randomization. For patients with CNS metastases confirmed at screening or subsequently suspected, CNS imaging was performed every 6 weeks for 18 months, then every 12 weeks. End points assessed by blinded independent central review and Response Evaluation Criteria in Solid Tumors version 1.1 included intracranial progression-free survival, intracranial objective response rate, and intracranial duration of response.

RESULTS

Of the 393 patients enrolled in LASER301, 86 (lazertinib, n = 45; gefitinib, n = 41) had measurable and or non-measurable baseline CNS metastases. The median intracranial progression-free survival in the lazertinib group was 28.2 months (95% confidence interval [CI]: 14.8-28.2) versus 8.4 months (95% CI: 6.7-not reached [NR]) in the gefitinib group (hazard ratio = 0.42, 95% CI: 0.20-0.89, p = 0.02). Among patients with measurable CNS lesions, the intracranial objective response rate was numerically higher with lazertinib (94%; n = 17) versus gefitinib (73%; n = 11, p = 0.124). The median intracranial duration of response with lazertinib was NR (8.3-NR) versus 6.3 months (2.8-NR) with gefitinib. Tolerability was similar to the overall LASER301 population.

CONCLUSIONS

In patients with CNS metastases, lazertinib significantly improved intracranial progression-free survival compared with gefitinib, with more durable responses.

Brain metastasis, EGFR mutation subtype and generation of EGFR-TKI jointly influence the treatment outcome of patient with EGFR-mutant NSCLC

Non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutation is brain metastasis (BM)-prone. We determined the impact of this hallmark, along with EGFR subtype and generation of tyrosine kinase inhibitor (TKI) treatment, on patients' outcome. 553 metastatic EGFR-mutant NSCLC patients received front-line EGFR-TKI treatment. Progression-free survival (PFS), overall survival (OS) and secondary T790M rate were analysed. BM was observed in 211 (38.2%) patients. BM (HR 1.20 [95% CI 0.99-1.48]; p = 0.053), ECOG PS 0-1 (HR 0.71 [95% CI 0.54-0.93]; p = 0.014) and afatinib treatment (HR 0.81 [95% CI 0.66-0.99]; p = 0.045) were associated with PFS. Afatinib-treated patients without BM demonstrated a significantly longer PFS (16.3 months) compared to afatinib-treated patients with BM (13.7 months) and to gefitinib/erlotinib-treated patients with (11.1 months) or without BM (14.2 months; p < 0.001). CNS-only progression trended higher in afatinib-treated patients. ECOG PS 0-1 (HR 0.41 [95% CI 0.31-0.56]; p < 0.001) and EGFR L858R mutation (HR 1.46 [95% CI 1.13-1.88]; p = 0.003), but not BM, were the predictors for OS. BM (OR 2.02 [95% CI 1.02-4.08]; p = 0.040), afatinib treatment (OR 0.26 [95% CI 0.12-0.50]; p < 0.001) and EGFR L858R mutation (OR 0.55 [95% CI 0.28-1.05]; p = 0.070) were associated with secondary T790M rate. In BM patients, gefitinib/erlotinib-treated ones with 19 deletion mutation and afatinib-treated ones with L858R mutation had the highest and the lowest T790M rate (94.4% vs. 27.3%, p < 0.001), respectively. BM and generation of EGFR-TKI jointly impact PFS and secondary T790M rate in patients with EGFR-mutant NSCLC, whereas OS was mainly associated with EGFR subtype.

Effects of concurrent TP53 mutations on the efficacy and prognosis of targeted therapy for advanced EGFR mutant lung adenocarcinoma

BACKGROUND

How concurrent TP53 mutations affect targeted therapy of advanced Epidermal Growth Factor Receptor (EGFR) mutant lung adenocarcinoma remains controversial, particularly the deep classification of TP53 mutations.

METHODS

This study retrospectively analyzed the clinical data of advanced EGFR mutant lung adenocarcinoma patients treated with EGFR-tyrosine kinase inhibitors (TKIs) in the First Affiliated Hospital of Soochow University. The survival rates were compared using Log-rank tests. Potential prognostic factors were identified using multivariate Cox hazard regression models.

RESULTS

Total 156 advanced lung adenocarcinoma patients treated with EGFR-TKIs were included in this study. Multivariate analysis showed that male [hazard rate (HR): 1.537, 95% confidence interval (CI): 1.055-2.240, P = 0.025], brain metastasis (HR: 1.707, 95%CI: 1.086-2.682, P = 0.020) and concurrent TP53 mutations (HR: 1.569, 95%CI: 1.051-2.341, P = 0.028) were independent negative predictors of progression-free survival (PFS). EGFR L858R mutations (HR: 2.475, 95%CI: 1.443-4.248, p = 0.001), smoking history (HR: 2.530, 95%CI: 1.352-4.733, P = 0.004) and concurrent TP53 mutations (HR: 2.326, 95%CI: 1.283-4.218, P = 0.005) were associated with worse survival. Further analysis revealed that mutations in TP53 exons 4, 5 and 8 (P<0.05), missense mutations (P = 0.006) and nondisruptive mutations (P<0.001) were associated with shorter PFS, whereas mutations in TP53 exons 5 and 7 (P<0.05), missense mutations and non-missense mutations (P = 0.006; P = 0.007), disruptive mutations and nondisruptive mutations (P = 0.013; P = 0.013) were all associated with poorer survival times. In addition, the PFS and overall survival (OS) of nondisruptive mutations in exon 7 were worse than those in other exons (P = 0.041; P<0.001).

CONCLUSIONS

Concurrent TP53 mutations conferred worse EGFR-TKIs efficacy and prognosis in advanced EGFR mutant lung adenocarcinoma and the effects of different TP53 mutation types were heterogeneous.

A Prospective Cohort Study Assessing the Relationship between Plasma Levels of Osimertinib and Treatment Efficacy and Safety

Osimertinib is a standard treatment for patients with EGFR-mutated non-small cell lung carcinoma (NSCLC). We evaluated the relationship between plasma osimertinib concentrations and treatment outcome in patients with NSCLC for this cohort study. The plasma levels of osimertinib and its metabolite AZ5104 were measured a week after the start of treatment (P1). The primary endpoint was to evaluate the correlation between plasma concentration and adverse events (AEs). The correlation with treatment efficacy was one of the secondary endpoints. In patients with CNS metastases, the concentration in the cerebrospinal fluid was also measured. Forty-one patients were enrolled. The frequency of AEs was highest for rash, followed by anorexia and thrombocytopenia. Thirty-eight cases provided measurements for P1. The median plasma concentration of osimertinib was 227 ng/mL, and that of AZ5104 was 16.5 ng/mL. The mean CNS penetration rate of two cases was 3.8%. The P1 in the group with anorexia was significantly higher than that in the group without anorexia (385.0 ng/mL vs. 231.5 ng/mL, p = 0.009). Divided into quartiles by P1 trough level, Q2 + Q3 (164-338 ng/mL) had longer PFS, while Q1 and Q4 had shorter PFS. An appropriate plasma level of osimertinib may avoid some adverse events and induce long PFS. Further large-scale trials are warranted.

Effect of Different Timing of Local Brain Radiotherapy on Survival of EGFR-Mutated NSCLC Patients with Limited Brain Metastases

(1) Background: Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have been the first line therapy for EGFR-mutant lung adenocarcinoma (LAC) patients with brain metastases (BMs). However, the role and the optimal time of brain radiotherapy remains controversial. We aimed to investigate the role of upfront brain stereotactic radiotherapy (SRS) and the impact of deferral radiotherapy on patients' clinical outcomes. (2) Methods: We retrospectively studied 53 EGFR-mutant LAC patients with limited synchronous BMs between 2014 and 2020 at our institute. The limited BMs was defined with one to four BM lesions, with a maximal size of ≤4 cm. Patients were categorized into two groups: upfront brain SRS (upfront RT) and upfront TKIs. The intracranial progression-free survival (iPFS), progression-free survival (PFS), and overall survival (OS) between groups were analyzed. (3) Results: The median iPFS (21.0 vs. 12.0 months, p = 0.002) and PFS (20.0 vs. 11.0 months, p = 0.004) of the upfront RT group was longer than that of the upfront TKI group. There were no significant differences in median OS (30.0 vs. 26.0 months, p = 0.552) between the two groups. The upfront RT group is less likely to suffer from intracranial progression of the original sites than that of upfront TKIs during the disease course (36.1% vs. 0.0%, p = 0.025). Multivariate analysis showed that the Karnofsky Performance Scale and the presence of synchronous meningeal metastases were associated with overall survival. (4) Conclusions: Compared with upfront TKI, the combination of upfront SRS with TKIs can improve the iPFS and PFS in EGFR-mutant LAC with synchronous BMs. The addition of upfront brain SRS was useful for the original intracranial metastatic lesions.

Targeting the epidermal growth factor receptor following complete surgical resection in patients with early-stage non-small cell lung cancer

INTRODUCTION

Activating mutations in the epidermal growth factor receptor (EGFR) gene are one of the most common targetable oncogenic drivers of non-small cell lung cancer (NSCLC). Osimertinib is a third-generation EGFR tyrosine kinase inhibitor (EGFR-TKI) that selectively inhibits EGFR-TKI sensitizing (ex19del or L858R) and T790M mutations and has superior CNS penetration. Osimertinib is approved in EGFR mutant stage IB-IIIA NSCLC following complete tumor resection.

AREAS COVERED

This review opinion article summarizes the pivotal studies that led to the approval of current adjuvant therapies in NSCLC with the primary focus on EGFR-TKI osimertinib and outlines the future strategies in the era of neoadjuvant immunotherapy and emerging novel roles of EGFR targeting therapies. The literature search has been performed using PubMed, Food and Drug Administration website, and Google search.

EXPERT OPINION

Osimertinib showed significant and clinically meaningful disease-free survival benefit compared to placebo in EGFR mutant stage IB-IIIA NSCLC following complete tumor resection. Whether this will lead to improvement in overall survival and the optimal length of treatment remain open questions and are much-debated topic in the lung cancer field.

Osimertinib Improves overall survival of EGFR-mutant NSCLC patients with leptomeningeal metastases

OBJECTIVE

Osimertinib is a third-generation, irreversible, small-molecule epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) that can effectively penetrate the blood brain-barrier (BBB). This study mainly explored the factors affecting the prognosis of EGFR-mutant advanced non-small cell lung cancer (NSCLC) patients with leptomeningeal metastases (LM), and whether osimertinib could improve the survival benefit in these patients compared with those not treated with osimertinib.

METHODS

We retrospectively analyzed patients who had been admitted with EGFR-mutant NSCLC and cytologically confirmed LM to the Peking Union Medical College Hospital between January 2013 and December 2019. Overall survival (OS) was defined as the primary outcome of interest.

RESULTS

A total of 71 patients with LM were included in this analysis, with a median OS (mOS) of 10.7 months (95% CI [7.6, 13.8]). Among them, 39 patients were treated with osimertinib after LM while 32 patients were untreated. Patients treated with osimertinib had a mOS of 11.3 months (95%CI [0, 23.9]) compared with the untreated patients who had a mOS of 8.1 months (95%CI [2.9, 13.3]), with a significant difference between the groups (hazard ratio [HR]): 0.43, 95%CI:0.22-0.66, p = 0.0009). Multivariate analysis revealed the use of osimertinib were correlated with superior OS with a HR of 0.43 (95%CI [0.25, 0.75]), with a statistically significant difference (p = 0.003).

CONCLUSIONS

Osimertinib can prolong the overall survival of EGFR-mutant NSCLC patients with LM and improve patient outcomes.

Clinical Outcomes of Patients with Epidermal Growth Factor Receptor-Mutated Non-Small-Cell Lung Cancer with Leptomeningeal Metastasis in the Modern Target Therapy Era

BACKGROUND

Leptomeningeal metastasis (LM) is a severe complication in patients with non-small-cell lung cancer (NSCLC) and the optimal treatment strategy remains a challenge. This study aimed to investigate the treatment strategies and clinical outcomes in these patients.

METHODS

We retrospectively reviewed the data of 44 patients with epidermal growth factor receptor (EGFR)-mutated NSCLC with LM between 2014 and 2020 at our institute. The patient characteristics, treatment approaches, LM progression-free survival (LMPFS) and overall survival (OS) after the diagnosis of LM (OSLM) were analyzed.

RESULTS

The median OSLM was 16.0 months and the 3-year OS rate was 22.5%. The PFSLM in EGFR T790M-positive NSCLC patients with leptomeingeal disease was significantly improved by initiation of third-generation tyrosine kinase inhibitors (TKIs) compared with that of patients who were T790M negative (14.0 vs. 7.0 months; P = 0.030). A significantly higher LM disease control rate was shown in patients who received third-generation TKIs compared with previous generations of TKIs (90.1% vs. 60.0%; P = 0.024). Better Eastern Cooperative Oncology Group performance status, EGFR exon 19del, and clinical improvement of LM after therapy were independently associated with better OS.

CONCLUSIONS

The survival of patients with NSCLC with LM has improved in the target therapy era. Our study provided real-world clinical evidence that patients with EGFR-mutated NSCLC who developed LM from previous TKIs can be benefit from third-generation EGFR-TKIs, especially for patients with EGFR T790M-positive.

Therapeutic Monitoring of Orally Administered, Small-Molecule Anticancer Medications with Tumor-Specific Cellular Protein Targets in Peripheral Fluid Spaces-A Review

Orally administered, small-molecule anticancer drugs with tumor-specific cellular protein targets (OACD) have revolutionized oncological pharmacotherapy. Nevertheless, the differences in exposure to these drugs in the systemic circulation and extravascular fluid compartments have led to several cases of therapeutic failure, in addition to posing unknown risks of toxicity. The therapeutic drug monitoring (TDM) of OACDs in therapeutically relevant peripheral fluid compartments is therefore essential. In this work, the available knowledge regarding exposure to OACD concentrations in these fluid spaces is summarized. A review of the literature was conducted by searching Embase, PubMed, and Web of Science for clinical research articles and case reports published between 10 May 2001 and 31 August 2022. Results show that, to date, penetration into cerebrospinal fluid has been studied especially intensively, in addition to breast milk, leukocytes, peripheral blood mononuclear cells, peritoneal fluid, pleural fluid, saliva and semen. The typical clinical indications of peripheral fluid TDM of OACDs were (1) primary malignancy, (2) secondary malignancy, (3) mental disorder, and (4) the assessment of toxicity. Liquid chromatography-tandem mass spectrometry was most commonly applied for analysis. The TDM of OACDs in therapeutically relevant peripheral fluid spaces is often indispensable for efficient and safe treatments.

Overall survival analysis of patients enrolled in a randomized phase III trial comparing gefitinib and erlotinib for previously treated advanced lung adenocarcinoma (WJOG5108LFS)

BACKGROUND

Since the overall survival (OS) of patients enrolled in the first clinical phase III trial (WJOG5108L) was not recorded owing to time constraints, the present study (WJOG5108LFS) with a longer follow-up (66.6 months) aimed to compare OS of those treated with erlotinib (ER) and gefitinib (GE) for lung adenocarcinoma with epidermal growth factor receptor (EGFR) mutation.

METHODS

Among 536 enrolled patients, 362 (67.5%) were EGFR mutation-positive, including 182 in the ER arm and 180 in the GE arm. Median survival time (MST) and progression-free survival (PFS) were calculated using Kaplan-Meier survival curves. OS and PFS were determined for patients with EGFR mutation.

RESULTS

MSTs of ER (n = 182) and GE arms (n = 180) were 31.97 and 27.98 months, respectively (P = 0.3573, hazard ratio = 1.116). MSTs of exon 19 mutation patients in ER (n = 99) and GE arms (n = 89) were 37.49 and 28.91 months, respectively (P = 0.3791). MSTs of L858 mutation patients in ER (n = 82) and GE arms (n = 89) were 22.98 and 27.79 months, respectively (P = 0.7836). In patients with brain metastasis harboring mutation, response rates were 32.8% and 22.2% (P = 0.160), MSTs were 23.46 and 23.89 months (P = 0.7410), and PFS were 9.49 and 6.98 months (P = 0.1481) in the ER (n = 67) and GE arms (n = 72), respectively.

CONCLUSIONS

No significant differences in OS were observed between the ER and GE arms in all patients with EGFR mutation and those with brain metastasis harboring EGFR mutation.

Leveraging Molecular and Immune-Based Therapies in Leptomeningeal Metastases

Leptomeningeal metastases represent an aggressive stage of cancer with few durable treatment options. Improved understanding of cancer biology, neoplastic reliance on oncogenic driver mutations, and complex immune system interactions have resulted in an explosion in cancer-directed therapy in the last two decades to include small molecule inhibitors and immune checkpoint inhibitors. Most of these therapeutics are underexplored in patients with leptomeningeal metastases, limiting extrapolation of extracranial and even intracranial efficacy outcomes to the unique leptomeningeal space. Further confounding our interpretation of drug activity in the leptomeninges is an incomplete understanding of drug penetration through the blood-cerebrospinal fluid barrier of the choroid plexus. Nevertheless, a number of retrospective studies and promising prospective trials provide evidence of leptomeningeal activity of several small molecule and immune checkpoint inhibitors and underscore potential areas of further therapeutic development for patients harboring leptomeningeal disease.

The role of targeted therapy and immune therapy in the management of non-small cell lung cancer brain metastases

Brain metastases are a significant source of morbidity and mortality in patients with non-small cell lung cancer. Historically, surgery and radiation therapy have been essential to maintaining disease control within the central nervous system due to poorly penetrant conventional chemotherapy. With the advent of targeted therapy against actionable driver mutations, there is potential to control limited and asymptomatic intracranial disease and delay local therapy until progression. In this review paper, intracranial response rates and clinical outcomes to biological and immune therapies are summarized from the literature and appraised to assist clinical decision making and identify areas for further research. Future clinical trials ought to prioritize patient-centered quality of life and neurocognitive measures as major outcomes and specifically stratify patients based on mutational marker status, disease burden, and symptom acuity.

Different Tyrosine Kinase Inhibitors Used in Treating EGFR-Mutant Pulmonary Adenocarcinoma with Brain Metastasis and Intracranial Intervention Have No Impact on Clinical Outcomes

Brain metastasis in patients with non-small-cell lung cancer (NSCLC) harboring epidermal growth factor receptor (EGFR) mutations is a factor of poor prognosis. We conducted a retrospective study to determine the optimal treatment strategy for EGFR-mutant NSCLC patients with brain metastasis receiving or not receiving intracranial intervention. A total of 186 patients treated with an EGFR TKI were enrolled in the study, and 79 (42%) received intracranial intervention. Patients who received intracranial intervention and those who did not had a similar treatment response rate (RR), progression-free survival (PFS) (median PFS: 11.0 vs. 10.0 months, p = 0.4842), and overall survival (OS) (median OS: 23.0 vs. 23.2 months, p = 0.2484). Patients treated with gefitinib, erlotinib, afatinib, or osimertinib had a similar RR (63%, 76%, 81%, or 100%, respectively, p = 0.1390), but they had significantly different PFS (median PFS: 7.5, 10.0, 14.8 months, or not reached, respectively, p = 0.0081). In addition, OS tended to be different between different EGFR TKI treatments (median OS of 19.2, 23.7, or 33.0 months for gefitinib, erlotinib, or afatinib treatments, respectively, p = 0.0834). Afatinib and osimertinib both demonstrated significantly longer PFS than gefitinib in a Cox regression model. Graded prognostic assessment (GPA) versions 2017 and 2022 stratified patients with different OS; patients with higher GPA index scores had significantly longer OS (p = 0.0368 and 0.0407 for version 2017 and 2022, respectively).

Leptomeningeal metastases in non-small cell lung cancer: Diagnosis and treatment

Leptomeningeal metastasis (LM) is a rare complication of non-small cell lung cancer (NSCLC) with highly mortality. LM will occur once tumor cells spread to the cerebrospinal fluid (CSF) space. Patients may suffer blindness, paralysis, and mental disorders that seriously affect their quality of life. There is a clear unmet need to improve the efficacy of diagnosis and treatment of LM. To better solve this problem, it is helpful to clarify the potential mechanisms of LM. Clinical manifestations, magnetic resonance imaging, and CSF biopsy are the key components in the diagnosis of NSCLC with LM. CSF cytology is insufficient and should be combined with liquid biology. The application of radiotherapy, intrathecal treatment, targeted therapy and immunotherapy provides more options for LM patients. Each treatment has a particular level of efficacy and can be used alone or in combination for individual patients. New technologies in radiotherapy, drug repositioning in intrathecal treatment, and the higher CSF permeability in TKIs have brought new breakthroughs in the treatment of LM. This review focused on clarifying the potential mechanisms, discussing the major clinical challenges, and summarizing recent advances in the diagnosis and treatment of LM from NSCLC. Future research is essential to improve the efficiency of diagnosis, to optimize therapy and to enhance patient prognosis.

Epidermal growth factor receptor mutations and brain metastases in non-small cell lung cancer

Studies have revealed that non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutations has a high incidence of brain metastases (BMs). However, the association between EGFR mutations and BMs remains unknown. This review summarizes detailed information about the incidence of BMs, clinical and imaging characteristics of BMs, brain surveillance strategies, influence of treatments on BMs, prognosis after BMs, and differences in EGFR mutations between paired primary tumors and BMs in EGFR-mutated NSCLC. The prognostic results demonstrate that patients with mutated EGFR have a higher incidence of BMs, EGFR tyrosine kinase inhibitors (EGFR-TKIs) (afatinib and osimertinib) delay the development of BMs, and patients with mutated EGFR with synchronous or early BMs have better overall survival after BMs than those with wild-type EGFR. The EGFR mutation status of BM sites is not always in accordance with the primary tumors, which indicates that there is heterogeneity in EGFR gene status between paired primary tumors and BMs. However, the EGFR gene status of the primary site can largely represent that of BM sites. Among patients developing synchronous BMs, patients with mutated EGFR are less likely to have central nervous system (CNS) symptoms than patients with wild-type EGFR. However, the possibility of neuro-symptoms is high in patients with metachronous BMs. Patients with mutated EGFR tend to have multiple BMs as compared to patients with wild-type EGFR. Regarding very early-stage NSCLC patients without neuro-symptoms, regular neuroimaging follow-up is not recommended. Among advanced NSCLC patients with EGFR mutation, liberal brain imaging follow-up in the first several years showed more advantages in terms of cost.

Local control of brain metastases with osimertinib alone in patients with EGFR-mutant non-small cell lung cancer

PURPOSE

Although osimertinib has excellent intracranial activity in metastatic non-small cell lung cancer (NSCLC) with exon 19 deletion or L858R EGFR alterations, measures of local control of brain metastases are less well-reported. We describe lesion-level outcomes of brain metastases treated with osimertinib alone.

METHODS

We retrospectively reviewed patients with EGFR-mutant NSCLC with untreated brain metastasis measuring ≥ 5 mm at the time of initiating osimertinib. Cumulative incidence of local recurrence in brain (LRiB) was calculated with death as a competing risk, and univariable and multivariable analyses were conducted to identify factors associated with LRiB.

RESULTS

We included 284 brain metastases from 37 patients. Median follow-up was 20.1 months. On initial MRI after starting osimertinib, patient-level response was complete response (CR) in 11 (15%), partial response (PR) in 33 (45%), stable disease (SD) in 18 (25%) and progressive disease (PD) in 11 (15%). The 1-year cumulative incidence of LRiB was 14% (95% CI 9.9-17.9) and was significantly different in patients with a CR (0%), PR (4%), and SD (11%; p = 0.02). Uncontrolled primary tumor (adjusted hazard ratio [aHR] 3.78, 95% CI 1.87-7.66; p < 0.001), increasing number of prior systemic therapies (aHR 2.12, 95% CI 1.49-3.04; p < 0.001), and higher ECOG score (aHR 7.8, 95% CI 1.99-31.81; p = 0.003) were associated with LRiB.

CONCLUSIONS

Although 1-year cumulative incidence of LRiB is < 4% with a CR or PR, 1-year cumulative incidence of LRiB is over 10% for patients with less than a PR to osimertinib on initial MRI. These patients should be followed closely for need for additional treatment such as stereotactic radiosurgery.

[Advances in Diagnosis and Treatment of Leptomeningeal Metastasis of Lung Cancer]

Leptomeningeal metastases (LM), a special type of metastasis in advanced lung cancer, is known for its severe clinical symptoms, rapid progression and poor prognosis. LM used to be featured with low clinical diagnosis rate, limited treatment options, poor treatment efficacy, and very short survival if treatment not given. Though cerebrospinal fluid (CSF) cytology remains to be the gold standard for the diagnosis of LM, the positive rate of the first CSF cytology even in patients with suggestive clinical symptoms and positive imaging generally does not exceed 50%, leading to a delay in the diagnosis and treatment of patients with LM. With the progress of targeted therapy for driver gene-positive lung cancer and immunotherapy for driver gene-negative lung cancer, the overall survival of patients with lung cancer has been prolonged, meanwhile incidence of LM has been increasing year by year. Current clinical research in this field center around how to improve diagnosis rate and to find effective treatment approaches. This paper reviews advances in diagnosis and treatment of LM of lung cancer..
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Efficacy and Safety of EGFR Tyrosine Kinase Inhibitors Combined with Cranial Radiotherapy for Brain Metastases from Non-Small-Cell Lung Cancer: A Protocol for a Systematic Review and Meta-Analysis

Introduction. Brain metastases (BMs) are common in non-small-cell lung cancer (NSCLC), which leads to a poor prognosis. As the two most effective strategies available, the use of combination of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) and radiotherapy (RT) is still controversial. This protocol proposes a methodology for carrying out a systematic review and meta-analysis that is aimed at (1) focusing on the efficacy and safety role of EGFR-TKIs combined with RT for BMs from NSCLC and (2) displaying the difference in efficacy of EGFR-TKIs owing to the sites and number of BMs, different types of RT, EGFR mutation status, and the subtypes of EGFR mutations by subgroup analysis. Methods and Analysis. Electronic databases including PubMed, Embase, CENTRAL, Web of Science, CBM, CNKI, Wanfang database, and VIP database will be searched from their inception until May 2022. Only randomized controlled trials evaluating the clinical efficacy and safety of EGFR-TKIs combined with RT on BMs of NSCLC will be included. Two reviewers will select the articles, assess the risk of bias, and extract data independently and in duplicate. The RoB 2 tool will be used to assess the quality of included studies. The meta-analysis of data synthesis will be performed with Stata 16. Publication bias will be assessed with the funnel plot method and the Egger test. Quality of the evidence will be evaluated by the GRADE system. Discussion. The approval of an ethical committee is not required. All the included trials will comply with the current ethical standards and the Declaration of Helsinki. Given the ongoing controversies regarding the optimal sequencing of the available and expanding treatment options for EGFR-TKIs in NSCLC with BMs, a synthesis of available, high-quality clinical research evidence is essential to advance our understanding in the treatment of this complex and common disease. This systematic review will evaluate available evidence, will try to provide optimized advice in the applications of EGFR-TKIs, and will be published in a high-quality journal. This study is registered with PROSPERO registration number CRD42021291509.

Predictors of Lung Adenocarcinoma With Leptomeningeal Metastases: A 2022 Targeted-Therapy-Assisted molGPA Model

Objective

To explore prognostic indicators of lung adenocarcinoma with leptomeningeal metastases (LM) and provide an updated graded prognostic assessment model integrated with molecular alterations (molGPA).

Methods

A cohort of 162 patients was enrolled from 202 patients with lung adenocarcinoma and LM. By randomly splitting data into the training (80%) and validation (20%) sets, the Cox regression and random survival forest methods were used on the training set to identify statistically significant variables and construct a prognostic model. The C-index of the model was calculated and compared with that of previous molGPA models.

Results

The Cox regression and random forest models both identified four variables, which included KPS, LANO neurological assessment, TKI therapy line, and controlled primary tumor, as statistically significant predictors. A novel targeted-therapy-assisted molGPA model (2022) using the above four prognostic factors was developed to predict LM of lung adenocarcinoma. The C-indices of this prognostic model in the training and validation sets were higher than those of the lung-molGPA (2017) and molGPA (2019) models.

Conclusions

The 2022 molGPA model, a substantial update of previous molGPA models with better prediction performance, may be useful in clinical decision making and stratification of future clinical trials.

Efficacy of Osimertinib in EGFR-Mutated Advanced Non-small-Cell Lung Cancer With Different T790M Status Following Resistance to Prior EGFR-TKIs: A Systematic Review and Meta-analysis

Purpose

Epidermal growth factor receptor (EGFR) T790M-negative/unknown advanced non-small cell lung cancer (NSCLC) patients lack subsequent approved targeted therapies. This meta-analysis aimed to assess the efficacy of osimertinib in advanced NSCLC patients with different T790M status after resistance to prior first- or second-generation EGFR-tyrosine kinase inhibitors (EGFR-TKIs) and to predict the subgroups that may benefit beside T790M-positive disease.

Methods

PubMed, Embase, Web of Science, and Cochrane Library databases were searched for relevant trials. Meeting abstracts were also reviewed to identify appropriate studies. Studies evaluating the efficacy and/or survival outcomes of osimertinib in patients with different T790M status (positive, negative, or unknown) after resistance to prior first- or second-generation EGFR-TKIs were enrolled, and data were pooled to assess hazard ratios (HRs) or relative risk ratios (RRs) in terms of overall survival (OS), progression-free survival (PFS), and objective response rate (ORR).

Results

A total of 1,313 EGFR-mutated NSCLC patients from 10 retrospective and one prospective studies treated with osimertinib after resistance to first- or second-generation EGFR-TKIs were included. In overall groups, T790M-positive patients showed an improved OS (HR=0.574, p=0.015), PFS (HR = 0.476, p = 0.017), and ORR (RR = 2.025, p = 0.000) compared with T790M-negative patients. In the brain metastases subgroup, no significant difference in OS was observed between T790M-positive and T790M-negative patients (HR = 0.75, p = 0.449) or between T790M-positive and T790M-unknown patients (HR = 0.90, p = 0.673). In the plasma genotyping subgroup, PFS was similar between T790M-positive and T790M-negative patients (HR = 1.033, p = 0.959).

Conclusion

Patients with progressive brain metastases on first- or second-generation EGFR-TKIs can benefit from subsequent osimertinib therapy regardless of T790M status. Patients with plasma T790M-negative status and lack of tissue genotyping should be allowed to receive osimertinib treatment.

The optimal therapy strategy for epidermal growth factor receptor-mutated non-small cell lung cancer patients with brain metastasis: A real-world study from Taiwan

BACKGROUND

The treatment options for epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC) with brain metastases (BMs) include EGFR-tyrosine kinase inhibitors (TKIs), stereotactic radiosurgery (SRS), whole-brain radiotherapy, brain surgery, and antiangiogenesis therapy. As treatment options evolve, redefining optimal treatment strategies to improve survival are crucial.

METHODS

A total of 150 EGFR-mutant NSCLC patients with BMs who received first- or second-generation EGFR-TKIs as first-line treatment between January 2012 and October 2019 were included in this analysis.

RESULTS

After multivariate analysis, patients with the graded prognostic assessment for lung cancer using molecular markers (Lung-mol GPA) ≥3 (hazard ratio [HR]: 0.538, 95% confidence interval [CI]: 0.35-0.83), who received afatinib or erlotinib as first-line treatment (HR: 0.521, 95% CI: 0.33-0.82), underwent SRS therapy (HR: 0.531, 95% CI: 0.32-0.87), or were sequentially treated with osimertinib (HR: 0.400, 95% CI: 0.23-0.71) were associated with improved overall survival (OS). Furthermore, SRS plus EGFR-TKI provided more OS benefits in patients with Lung-mol GPA ≥3 compared with EGFR-TKI alone in our patient cohort (44.9 vs. 26.7 months, p = 0.005). The OS in patients who received sequential osimertinib therapy was significantly longer than those without osimertinib treatment (43.5 vs. 24.3 months, p < 0.001), regardless of T790 mutation status (positive vs. negative vs. unknown: 40.4 vs. 54.6 vs.43.4 months, p = 0.227).

CONCLUSIONS

The study demonstrated that EGFR-mutant NSCLC patients with BMs could be precisely treated with SRS according to Lung-mol GPA ≥3. Sequential osimertinib was associated with prolonged survival, regardless of T790M status.

Standard-Dose Osimertinib in EGFR-Mutated Non-Small-Cell Lung Adenocarcinoma With Leptomeningeal Disease

PURPOSE

Leptomeningeal disease (LMD) in epidermal growth factor receptor (EGFR)-mutant lung adenocarcinoma is associated with a poor prognosis and limited treatment options. Osimertinib is a potent third-generation EGFR tyrosine kinase inhibitor with confirmed CNS penetration. This study reports on outcomes of patients with EGFR-mutated non-small-cell lung cancer who developed LMD and were subsequently treated with osimertinib.

METHODS

We identified patients treated with osimertinib 80 mg PO daily under a compassionate access scheme across nine tertiary Australian institutes between July 2017 and July 2020. Patient demographics, tumor characteristics, and treatment history were collected. Median overall survival, median progression-free survival, disease control rates (DCR), and overall response rates (ORR) were assessed. Kaplan-Meier analysis was performed and descriptive statistics were used.

RESULTS

Thirty-nine patients were analyzed of which 74% were female. Exon 19 deletions (49%) and L858R point mutations (41%) were the most common EGFR mutations. Forty-nine percentage of patients were Eastern Cooperative Oncology Group 1. The median duration of osimertinib therapy was 6 months. The extracranial DCR and ORR were 60% and 54%, and the intracranial DCR and ORR were 68% and 53%, respectively. Median overall survival was 10.5 months (95% CI, 8.17 to 15.05 months).

CONCLUSION

There are limited treatment options for LMD in EGFR-positive lung cancer, and osimertinib at a dose of 80 mg daily is an active therapeutic option for these patients.

A Retrospective Study of Intrathecal Pemetrexed Combined With Systemic Therapy for Leptomeningeal Metastasis of Lung Cancer

Objective This retrospective study aimed to investigate the clinical features of lung cancer patients with leptomeningeal metastasis (LM) and explore the clinical efficacy and tolerance of intrathecal pemetrexed (IP) combined with systemic antitumor therapy. Methods Thirty-four lung cancer patients (11 men, 23 women) with LM receiving IP at our hospital were retrospectively reviewed between August 2018 and December 2019. Identified cases showed either positive cerebrospinal fluid cytology or typical findings (leptomeningeal enhancement or ventricle broadening) upon imaging examination. Results Before the diagnosis of LM, 24 (70.6%) patients received EGFR-TKI therapy with or without other agents (antivascular therapy, or chemotherapy), 5 (14.7%) patients received chemotherapy, 1 (2.9%) patient received antivascular therapy, and 3 (8.8%) patients received ALK inhibitors. Fourteen (41.2%) patients did not change the systematic regimen at the beginning of IP, while 20 (58.8%) patients changed to antitumor agents. IP was administered for a median of 3 times (range, 1-12 times). The IP dose was 15, 20, 25, 30, and 40 mg in 8 (23.5%), 21 (58.8%), 2 (5.9%), 2 (5.9%), and 1 (5.9%) patient, respectively. In all IP dose levels, the major adverse events were myelosuppression and elevation of hepatic aminotransferases (EHA). Grade 1/2 myelosuppression occurred in 4 (11.8%) patients. Grade 1/2 EHA also occurred in 4 (11.8%) patients. Grades 3/4 adverse events were not observed. After IP and systematic therapy, the clinical manifestations related to LM in 26 (76.5%) patients improved. In the whole cohort, the median overall survival was 20 months. The median time from the initial IP administration until death or the last follow-up was 3.5 months. Conclusions IP showed controllable toxicity and good efficacy, prolonged the survival time, and improved the quality of life when combined with tailored systemic antitumor therapy in lung cancer patients.

Overall survival benefit of Osimertinib and clinical value of upfront cranial local therapy in untreated EGFR-mutant non-small cell lung cancer with brain metastasis

Osimertinib, as a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI), showed more potent efficacy against brain metastasis (BM) in untreated EGFR-mutant non-small cell lung cancer (NSCLC) in the FLAURA study. However, the overall survival (OS) benefit of Osimertinib and clinical value of cranial local therapy (CLT) in these patients remain undetermined. Here we conducted a retrospective study involving untreated EGFR-mutant NSCLC patients with BMs receiving first-line osimertinib or first-generation EGFR-TKIs. Upfront CLT was defined as CLT performed before disease progression to the first-line EGFR-TKIs. Pattern of treatment failure and survival outcomes were extensively investigated. Among the 367 patients enrolled, first-generation EGFR-TKI was administered in 265, osimertinib in 102 and upfront CLT performed in 140. Patients receiving osimertinib had more (p<0.001) and larger BMs (p=0.003) than those receiving first-generation EGFR-TKIs. After propensity score matching (PSM), osimertinib was found to prolong OS (37.7 months vs. 22.2 months, p=0.027). Pattern of failure analyses found that 51.8% of the patients without upfront CLT developed their initial progressive disease (PD) in the brain and 59.0% of the cranial PD occurred at the original sites alone, suggesting potential clinical value of upfront CLT. Indeed, upfront stereotactic radiosurgery (SRS) and/or surgery was associated with improved OS among those receiving first-generation EGFR-TKIs (p=0.019) and those receiving osimertinib (p=0.041). In summary, compared with first-generation EGFR-TKIs, osimertinib is associated with improved OS in untreated EGFR-mutant NSCLC with BMs. Meanwhile, upfront SRS and/or surgery may provide extra survival benefit, which needs to be verified in future studies. This article is protected by copyright. All rights reserved.

Research Progress and Challenges in the Treatment of Central Nervous System Metastasis of Non-Small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) is one of the most common malignant tumors and has high morbidity and mortality rates. Central nervous system (CNS) metastasis is one of the most frequent complications in patients with NSCLC and seriously affects the quality of life (QOL) and overall survival (OS) of patients, with a median OS of untreated patients of only 1-3 months. There are various treatment methods for NSCLC CNS metastasis, including surgery, chemotherapy, radiotherapy, targeted therapy, and immunotherapy, which do not meet the requirements of patients in terms of improving OS and QOL. There are still many problems in the treatment of NSCLC CNS metastasis that need to be solved urgently. This review summarizes the research progress in the treatment of NSCLC CNS metastasis to provide a reference for clinical practice.

EGFR-mutated stage IV non-small cell lung cancer: What is the role of radiotherapy combined with TKI?

Lung cancer is the leading cause of cancer-related death globally and poses a considerable threat to public health. Asia has the highest prevalence of epidermal growth factor receptor (EGFR) mutations in patients with non-small cell lung cancer (NSCLC). Despite the reasonable response and prolonged survival associated with EGFR-tyrosine kinase inhibitor (TKI) therapy, the acquisition of resistance to TKIs remains a major challenge. Additionally, patients with EGFR mutations are at a substantially higher risk of brain metastasis compared with those harboring wild-type EGFR. The role of radiotherapy (RT) in EGFR-mutated (EGFRm) stage IV NSCLC requires clarification, especially with the advent of next-generation TKIs, which are more potent and exhibit greater central nervous system activity. In particular, the feasible application of RT, including the timing, site, dose, fraction, and combination with TKI, merits further investigation. This review focuses on these key issues, and provides a flow diagram with proposed treatment options for metastatic EGFRm NSCLC, aiming to provide guidance for clinical practice.

A Phase II Study of Osimertinib for Radiotherapy-Naive Central Nervous System Metastasis From NSCLC: Results for the T790M Cohort of the OCEAN Study (LOGIK1603/WJOG9116L)

OBJECTIVES

Osimertinib has been reported to be effective against central nervous system (CNS) metastasis from activating EGFR mutation-positive NSCLC. Nevertheless, the true antitumor effects of osimertinib alone for CNS metastasis are unclear because the aforementioned studies included previously irradiated cases, in which tumor shrinkage can occur later owing to the effects of radiotherapy (RT). This study aimed to evaluate the efficacy of osimertinib against RT-naive CNS metastasis from sensitizing EGFR mutation-positive NSCLC.

METHODS

The OCEAN study was a two-cohort trial, involving 66 patients (T790M cohort [n = 40] and first-line cohort [n = 26]) with RT-naive CNS metastasis from sensitizing EGFR mutation-positive NSCLC. The patients were treated once daily with 80 mg osimertinib. The primary end point was brain metastasis response rate (BMRR) according to the PAREXEL criteria. In this report, we present the results for the T790M cohort with analysis of drug concentrations and plasma circulating tumor DNA.

RESULTS

The median age of the patients was 69 years, and 30% of them were males. Eight patients (20%) were symptomatic, and most had multiple CNS metastases (78%). Among the eligible 39 patients, the BMRR (PAREXEL criteria), median brain metastasis-related progression-free survival (PFS), median overall survival, overall response rate, and median PFS were 66.7% (90% confidence interval: 54.3%-79.1%), 25.2 months, 19.8 months, 40.5%, and 7.1 months, respectively. The BMRR according to the Response Evaluation Criteria in Solid Tumors criteria was 70.0% (n = 20). The brain metastasis-related PFS of patients with EGFR exon 19 deletion was significantly longer than that of exon 21 L858R (median = 31.8 versus 8.3 mo; log-rank p = 0.032). The treatment-related pneumonitis was observed in four patients (10%). On or after day 22, the median trough blood and cerebrospinal fluid concentrations of osimertinib were 568 nM and 4.10 nM, respectively, and those of its metabolite AZ5104 were 68.0 nM and 0.260 nM, respectively. The median blood to cerebrospinal fluid penetration rates of osimertinib and AZ5104 were 0.79% and 0.53%, respectively. The blood trough concentration at day 22 was not correlated with the efficacy of osimertinib against CNS metastasis. Plasma T790M and C797S mutations were detected in 83% and 3% of the patients before treatment, 11% and 3% of the patients on day 22, and 39% and 22% of the patients at the detection of progressive disease, respectively.

CONCLUSIONS

This study evaluated the efficacy of osimertinib against RT-naive CNS metastasis from T790M-positive NSCLC. The primary end point was met, and the results revealed the efficacy of osimertinib in patients with CNS metastasis harboring EGFR T790M mutations especially for EGFR-sensitizing mutation of exon 19 deletion.

Osimertinib Improves Overall Survival in Patients with Leptomeningeal Metastases Associated with EGFR-Mutated Non-Small-Cell Lung Cancer Regardless of Cerebrospinal Fluid T790M Mutational Status

Osimertinib has demonstrated promising efficacy against leptomeningeal metastasis (LM) associated with T790M-positive non-small-cell lung cancer (NSCLC). However, the effect of cerebrospinal fluid's (CSF's) epidermal growth factor receptor (EGFR) T790M mutation on osimertinib efficacy remains unclear.Seventy-eight patients were studied with EGFR-mutated NSCLC and LM. Case data were collected and EGFR mutation status of circulating cell-free DNA from paired CSF, and plasma of 23 patients with LM was detected using droplet digital PCR. The median overall survival (mOS) was 8.08 months (95% CI: 6.07-10.09) in the study. Forty-four osimertinib-treated patients had an improved mOS of 13.15 (95% CI: 5.74-20.57) and a median progression-free survival (PFS) of 9.50 months (95% CI: 6.77-12.23) when compared with patients treated with first- or second-generation EGFR-TKI (mOS = 3.00 months (95% CI: 1.32-4.68) and median PFS = 1.50 months (95% CI: 0.00-3.14)). In the osimertinib group, mOS values for CSF with and without T790M mutation were 22.15 months (95% CI: 9.44-34.87) and 13.39 months (95% CI: 7.01-19.76), respectively, with no statistical differences. Regardless of the CSF T790M mutation status, osimertinib demonstrated significant efficacy against LM associated with NSCLC.

Advances in targeted therapy in non-small cell lung cancer with actionable mutations and leptomeningeal metastasis

WHAT IS KNOWN AND OBJECTIVE?: Leptomeningeal metastasis (LM) is a serious complication of advanced non-small cell lung cancer (NSCLC) that is diagnosed in approximately 3%-5% of patients. LM occurs more frequently in patients with NSCLC harbouring epidermal growth factor receptor (EGFR) mutations or anaplastic lymphoma kinase (ALK) rearrangements and is usually accompanied by a poor prognosis, with a median overall survival (OS) of several months if patients receive conventional treatments. However, tyrosine kinase inhibitor (TKI) therapy after LM diagnosis is an independent predictive factor for extended survival. Here, we aim to summarize the latest advances in targeted therapy for LM and provide patients with better treatment options. METHODS: By reviewing the recent progress of targeted therapy in NSCLC with LM, especially the efficacy of newer generation TKIs, we aim to provide clinicians with a reference to further optimize patient treatment plans. RESULTS AND DISCUSSION: Osimertinib was confirmed to have a several-fold higher CNS permeability than other EGFR-TKIs and was recommended as the preferred choice for patients with EGFR-positive LM whether or not they harboured the T790M mutation. Second-generation ALK-TKIs have a higher rate of intracranial response and can be positioned as front-line drugs in NSCLC with LM. However, the sequence in which ALK-TKIs are administered for effective disease control requires further evaluation. In addition, targeted therapy revealed a potential choice in patients with LM and rare mutations, such as ROS1 and BRAF. WHAT IS NEW AND CONCLUSIONS?: The development of therapeutic agents with greater CNS penetration is vital for the management of CNS metastasis from NSCLC, particularly in the EGFR-mutant and ALK-rearranged subtypes. Systemic therapy with newer generation TKIs is preferred as the initial intervention. This is because newer generation TKIs are designed to penetrate the blood-brain barrier and possess significantly higher intracranial activities. However, their further effectiveness is limited by inadequate blood-brain barrier penetration and acquired drug resistance. Further studies are needed to further understand the mechanisms underlying resistance to treatment.

Rechallenge with previously administered epidermal growth factor receptor-tyrosine kinase inhibitors in EGFR-mutated non-small cell lung cancer with leptomeningeal metastasis

Objectives In EGFR-mutated non-small cell lung cancer (NSCLC) patients, approximately 80-90% of leptomeningeal metastasis (LM) develops after failed initial treatment with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (EGFR-TKI). However, the efficacy of rechallenging with previously administered EGFR-TKIs in patients with EGFR-mutated NSCLC and the LM that develops following EGFR-TKI treatment failure remains unknown. Materials and methods We retrospectively reviewed medical records of patients with EGFR-mutated NSCLC and LM, from November 2011 to August 2019. The patients were classified according to the LM treatment type: switched to previously unadministered EGFR-TKIs (Switch-TKI) or rechallenge with previously administered EGFR-TKIs (Rechallenge-TKI). Results In total, 50 patients treated with EGFR-TKI after LM diagnosis were included; 35 were treated with Switch-TKI and 15 with Rechallenge-TKI. The median overall survival (OS) from the time of LM diagnosis was 6.2 months in all study patients. According to the treatment type, the median OS from the time of LM diagnosis was 6.9 months in Switch-TKI patients and 4.9 months in Rechallenge-TKI patients. There was no significant difference in the OS between the Switch-TKI and Rechallenge-TKI groups (P = 0.864). Thirty-five patients were treated with erlotinib and 15 with osimertinib; Regardless of the type for EGFR-TKI, there was no significant difference in OS between patients treated with Switch-TKI and those treated with Rechallenge-TKI. Conclusion Rechallenge of previously administered EGFR-TKIs may be a therapeutic option for LM development after EGFR-TKI treatment failure in patients with EGFR-mutated NSCLC, not only switching to previously unadministered EGFR-TKIs.

Whole-brain radiotherapy with and without concurrent erlotinib in NSCLC with brain metastases: a multicenter, open-label, randomized, controlled phase III trial

BACKGROUND

Erlotinib combined with whole-brain radiotherapy (WBRT) demonstrated a favorable objective response rate in a phase II single-arm trial of non-small cell lung cancer (NSCLC) patients with brain metastases. We assessed whether concurrent erlotinib with WBRT is safe and benefits patients in a phase III, randomized trial.

METHODS

NSCLC patients with two or more brain metastases were enrolled and randomly assigned (1:1) to WBRT (n = 115) or WBRT combined with erlotinib arms (n = 109). The primary endpoint was intracranial progression-free survival (iPFS) and cognitive function (CF) was assessed by the Mini-Mental State Examination (MMSE).

RESULTS

A total of 224 patients from 10 centers across China were randomized to treatments. Median follow-up was 11.2 months. Median iPFS for WBRT concurrent erlotinib was 11.2 months vs 9.2 months for WBRT-alone (P = .601). Median PFS and overall survival (OS) of combination group were 5.3 vs 4.0 months (P = .825) and 12.9 vs 10.0 months (P = .545), respectively, compared with WBRT-alone. In EGFR-mutant patients, iPFS (14.6 vs 12.8 months; P = .164), PFS (8.8 vs 6.4 months; P = .702), and OS (17.5 vs 16.9 months; P = .221) were not significantly improved in combination group over WBRT-alone. Moreover, there were no significant differences in patients experiencing MMSE score change between the treatments.

CONCLUSION

Concurrent erlotinib with WBRT didn't improve iPFS and excessive CF detriment either in the intent-to-treat (ITT) population or in EGFR-mutant patients compared with WBRT-alone, suggesting that while safe for patients already taking the drug, there is no justification for adding concurrent EGFR-TKI with WBRT for the treatment of brain metastases. Trial registration: Clinical trials.gov identifier: NCT01887795.

Osimertinib rechallenge under steroid protection following osimertinib-induced pneumonitis: three case studies

Osimertinib is a third-generation tyrosine kinase inhibitor that became the preferred first-line treatment option for metastatic non-small cell lung cancer with sensitizing epidermal growth factor receptor mutations. Drug-induced pneumonitis is known to occur with osimertinib. In case of severe pneumonitis, discontinuation of treatment and therapy with corticosteroids is recommended, and a treatment switch is usually performed. We herein report the treatment course in three patients who were rechallenged with osimertinib under steroid protection following an osimertinib-induced pneumonitis. All our patients were initially re-exposed to a lower dose of osimertinib. Two patients were successfully rechallenged under prednisolone protection. The third patient, who was initially retreated with osimertinib without steroid protection, suffered from a recurrent pneumonitis, and was later rechallenged successfully under steroid protection. Our case series indicates that rechallenge with osimertinib following recovery from osimertinib-induced pneumonitis allows a successful rechallenge in individual cases when alternative treatment options are lacking. Concomitant steroids appear to protect against flares of pneumonitis during rechallenge.

Translational CNS Steady-State Drug Disposition Model in Rats, Monkeys, and Humans for Quantitative Prediction of Brain-to-Plasma and Cerebrospinal Fluid-to-Plasma Unbound Concentration Ratios

Capturing unbound drug exposure in the brain is crucial to evaluate pharmacological effects for drugs acting on the central nervous system. However, to date, there are no reports of validated prediction models to determine the brain-to-plasma unbound concentration ratio (K_p,uu,brain) as well as the cerebrospinal fluid (CSF)-to-plasma unbound concentration ratio (K_p,uu,CSF) between humans and other species. Here, we developed a translational CNS steady-state drug disposition model to predict K_p,uu,brain and K_p,uu,CSF across rats, monkeys, and humans by estimating the relative activity factors (RAF) for MDR1 and BCRP in addition to scaling factors (γ and σ) using the molecular weight, logD, CSF bulk flow, and in vitro transport activities of these transporters. In this study, 68, 26, and 28 compounds were tested in the rat, monkey, and human models, respectively. Both the predicted K_p,uu,brain and K_p,uu,CSF values were within the 3-fold range of the observed values (71, 73, and 79%; 79, 88, and 78% of the compounds, respectively), indicating successful prediction of K_p,uu,brain and K_p,uu,CSF in the three species. The overall predictivity of the RAF approach is consistent with that of the relative expression factor (REF) approach. As the established model can predict K_p,uu,brain and K_p,uu,CSF using only in vitro and physicochemical data, this model would help avoid ethical issues related to animal use and improve CNS drug discovery workflow.

Prophylactic cranial irradiation in non-small cell lung cancer: evidence and future development

In non-small cell lung cancer (NSCLC) brain metastases (BM) will affect up to 50% of patients during whole disease period. BM themselves impact heavily not only on patient’s prognosis but also are a source of symptoms aggravating quality of life. Standard (pemetrexed), and non-standard chemotherapy (temozolomide) in patients with NSCLC failed to prevent them from BM. In terms of systemic treatment there are promising results showed when durvalumab (PACIFIC study), osimertinib (FLAURA trial) or alectinib (JALEX study) was used. However, those substances are effective only in small cohort with ALK or EGFR alterations. Prophylactic cranial irradiation (PCI) as a non-specific treatment has proven to be a powerful tool in preventing BM without affecting overall survival in neither way. That has been proved in nearly all earlier and all recent studies—NVALT11/DLCRG-02, RTOG 0214 update, Li et al. The positive effect of BM incidence reduction may draw fear form PCI usage due to potential cognitive toxicity the PCI may cause. Results of recent trials show that after PCI only mild cognitive disorders (MCD) may arise. Promising results in terms of reducing MCD are shown when memantine is used or/and hippocampal avoidance techniques are implemented. HA in PCI seem to be cost effective but calculations were made on small-cell lung cancer cohorts. Still even recent studies did not clarify finally which patients could benefit from PCI or other forms of preventing BM. It seems that new trials should focus on younger, fit and non-squamous histology patients and use the tests for mild cognitive disorders (MoCA, BHA) rather than screening tests for dementia (MMSE, HVLT, ADL). The main obstacle in performing new trials on PCI in NSCLC cohorts may be, however, patients’ accrual, as a difficulty which occurred during latest trials.

Challenges and Novel Opportunities of Radiation Therapy for Brain Metastases in Non-Small Cell Lung Cancer

Simple Summary

Lung cancer is the most common primary malignancy that tends to metastasize to the brain. Owing to improved survival of lung cancer patients, the prevalence of brain metastases is a matter of growing concern. Brain radiotherapy remains the mainstay in the management of metastatic CNS disease. However, new targeted therapies such as the tyrosine kinase or immune checkpoint inhibitors have demonstrated intracranial activity and promising tumor response rates. Here, we review the current and emerging therapeutical strategies for brain metastases from non-small cell lung cancer, both brain-directed and systemic, as well as the uncertainties that may arise from their combination.

Abstract

Approximately 20% patients with non-small cell lung cancer (NSCLC) present with CNS spread at the time of diagnosis and 25–50% are found to have brain metastases (BMs) during the course of the disease. The improvement in the diagnostic tools and screening, as well as the use of new systemic therapies have contributed to a more precise diagnosis and prolonged survival of lung cancer patients with more time for BMs development. In the past, most of the systemic therapies failed intracranially because of the inability to effectively cross the blood brain barrier. Some of the new targeted therapies, especially the group of tyrosine kinase inhibitors (TKIs) have shown durable CNS response. However, the use of ionizing radiation remains vital in the management of metastatic brain disease. Although a decrease in CNS-related deaths has been achieved over the past decade, many challenges arise from the need of multiple and repeated brain radiation treatments, which carry along not insignificant risks and toxicity. The combination of stereotactic radiotherapy and systemic treatments in terms of effectiveness and adverse effects, such as radionecrosis, remains a subject of ongoing investigation. This review discusses the challenges of the use of radiation therapy in NSCLC BMs in view of different systemic treatments such as chemotherapy, TKIs and immunotherapy. It also outlines the future perspectives and strategies for personalized BMs management.

Efficacy and safety of treatment modalities across EGFR selected/unselected populations with non-small cell lung cancer and brain metastases: A systematic review and Bayesian network meta-analysis

OBJECTIVE

To compare the efficacy and safety of treatment modalities across different populations with non-small cell lung cancer and brain metastases.

METHODS

A comprehensive search for randomized controlled trials was conducted in databases including PubMed, Embase, the Cochrane library, the ClinicalTrials.gov, and major international conferences. The main outcomes of interest were progression-free survival, overall survival, and severe adverse events. Bayesian network meta-analytical techniques were implemented, to compare treatment modalities based on efficacy and safety profiles. The protocol for this study has been registered in the Prospective Register of Systematic Reviews (PROSPERO, CRD42020155330).

RESULTS

15 randomized controlled trials with a total of 1216 patients were analyzed. Network meta-analysis generated six comparisons both in EGFR positive and EGFR unselected populations. For patients harboring EGFR positive mutations, osimertinib appears to significantly increase progression-free survival, compared to 1st generation EGFR-TKI (HR 0.46, 95 %CI 0.38-0.55), 2nd generation EGFR-TKI (HR: 0.59, 95 %CI 0.34-0.99), conventional chemotherapy (HR 0.30, 95 %CI 0.14-0.66), radiotherapy (HR 0.20, 95 %CI 0.14-0.29), and radiotherapy plus 1st generation TKI (HR 0.21, 95 %CI 0.14-0.32). Osimertinib also appears to increase the likelihood of survival and prolong overall survival. For EGFR unselected patients, combined anti-PD1 monoclonal antibody with conventional chemotherapy appears superior to radiotherapy (HR: 0.20, 95 % CI 0.14-0.29), conventional chemotherapy (HR: 0.42, 95 %CI 0.28-0.68), radiotherapy plus conventional chemotherapy (HR: 0.59, 95 %CI 0.32-0.98), radiotherapy plus 1st generation TKI (HR:0.49, 95 %CI 0.25-0.96), and immune checkpoint inhibitors monotherapy (HR:0.44, 95 %CI 0.28-0.69). However, combination therapies are generally more toxic causing an increased number of severe adverse events, particularly when anti-PD1 monoclonal antibody is combined with conventional chemotherapy.

CONCLUSIONS

Osimertinib appears to be the most effective and safest treatment in NSCLC patients with brain metastases, harboring EGFR positive mutations. The anti-PD1 monoclonal antibody and conventional chemotherapy combination increases survival for NSCLC patients with brain metastases who were not selected according to EGFR mutation, although this increased benefit positively correlates with an increased number of severe adverse events.

Activity and bioavailability of tepotinib for leptomeningeal metastasis of NSCLC with MET exon 14 skipping mutation

Tepotinib is a key drug for cancer patients with mesenchymal‐epithelial transition receptor tyrosine kinase proto‐oncogene (MET) exon 14 skipping mutation. However, its bioavailability in the cerebrospinal fluid (CSF) in humans has not been fully elucidated. Moreover, information about the efficacy of tepotinib in patients with leptomeningeal metastasis is limited. Here, we present the case of a 56‐year‐old man who was diagnosed with lung adenocarcinoma with MET exon 14 skipping mutation. He was urgently hospitalized due to leptomeningeal metastasis. We administered tepotinib 500 mg/day as the second‐line therapy and observed improvement in leptomeningeal metastasis and performance status. The tepotinib concentrations reached 1,648 ng/mL in the plasma and 30.6 ng/mL in the CSF, with a penetration rate (CSF/plasma) of 1.83%. These demonstrate tepotinib could achieve a high rate of central nervous system transition and could be effective against leptomeningeal metastasis.

Treatment Options for Leptomeningeal Metastases of Solid Cancers: Literature Review and Personal Experience

Leptomeningeal metastases (LM) may complicate the clinical course of any solid cancer or hematological malignancy. Diagnosis of such cases requires a multifaceted approach, including careful evaluation of the clinical history, detailed neurological examination, advanced imaging studies, and related laboratory data analysis. Therapeutic options for management of LM have not been standardized yet. Conventional intrathecal chemotherapy with or without involved-field fractionated radiotherapy has only modest efficacy, and the prognosis of most patients remains grim. Therefore, development of new, more aggressive multimodal treatment strategies is definitely needed. Immune checkpoint inhibitors-in particular, molecular targeted therapy-have demonstrated promising results in selected groups of patients. There may be an important role for stereotactic radiosurgery as well. Because organization of prospective randomized multi-institutional trials on treatment of LM of solid cancers may be problematic, practical guidelines for optimal therapeutic strategies in such cases should be established on the basis of integrated results of small-scale prospective and retrospective studies.

Use of Gefitinib in EGFR-Amplified Refractory Solid Tumors: An Open-Label, Single-Arm, Single-Center Prospective Pilot Study

BACKGROUND

Treatment options for patients with chemotherapy-refractory solid tumors are limited.

OBJECTIVE

We conducted an open-label, single-arm, single-center phase II trial to evaluate the efficacy and safety of gefitinib in patients with chemotherapy-refractory solid tumors and EGFR amplification or sensitivity to an EGFR inhibitor identified through a drug-screening platform with patient-derived tumor cells (PDCs).

PATIENTS AND METHODS

EGFR amplification was detected by targeted sequencing. Sensitivity to an EGFR inhibitor was established in chemical screening using PDCs. Gefitinib (250 mg daily) was administered continuously in 28-day cycles until the occurrence of disease progression, unacceptable toxicity, or death due to any cause. The primary endpoint was the objective response rate (ORR).

RESULTS

In total, 15 patients were assigned to the present study. The most common tumor type was glioblastoma multiforme (n = 9, 60%), followed by gastric cancer (n = 3, 20%), anal squamous cancer, rectal cancer, and sarcoma (each n = 1, 6.7%). Among 13 evaluable patients, one patient had a partial response and five had stable disease, with an ORR of 7.7% and a disease control rate of 46.1%. The median progression-free survival was 2.1 months (95% confidence interval [CI] 0.77-3.43). The most common adverse events were diarrhea (26.7%) and skin rash (26.7%).

CONCLUSION

Gefitinib demonstrated modest anti-tumor activity and a manageable safety profile in chemotherapy-refractory solid tumors with EGFR amplification or sensitivity to an EGFR inhibitor identified through a drug-screening platform with PDCs. CLINICALTRIALS.

GOV IDENTIFIER

NCT02447419.

Central nervous system metastases and oligoprogression during treatment with tyrosine kinase inhibitors in oncogene-addicted non-small cell lung cancer: how to treat and when?

Up to 70% of non-small cell lung cancer (NSCLC) patients develop central nervous system (CNS) metastases during the course of their disease, especially those with oncogenic drivers treated with a first-generation tyrosine kinase inhibitor (TKI), because of the relatively poor CNS penetration. CNS metastases are associated with a negative impact on quality of life and survival. As, with the introduction of newer generation TKIs, the survival rates are increasing in this particular population, treatment and/or prevention of CNS metastases becomes even more relevant and the TKI with the best CNS efficacy should be selected. Unfortunately, CNS efficacy data in clinical trials are not fully comparable. Furthermore, oligoprogression to the brain without extracranial progression regularly occurs in the oncogenic driver population and both local therapy and switch of systemic therapy are possible treatment options. However, the best order of systemic and local therapy is still not precisely known. In this narrative review, we will summarize incidence and treatment of CNS metastases in oncogene driven NSCLC, including the optimal treatment of CNS oligometastatic disease (synchronous as well as oligoprogressive).

Brain metastases in metastatic cancer: a review of recent advances in systemic therapies

Introduction: Brain metastases (BM) are a frequent complication of metastatic cancer. Due to the wider availability and application of screening procedures, an increasing fraction of patients are diagnosed at the asymptomatic stage. The introduction of immune checkpoint inhibitors and targeted therapies has revolutionized treatment in several frequently BM-causing entities like metastatic lung cancer, melanoma and breast cancer. However, registered trials of new targeted and immunotherapy mostly excluded patients with BM resulting in limited knowledge of the intracranial efficacy of new systemic agents.Areas covered: The present review highlights recent advances in systemic therapies for the treatment and prophylaxis of the three leading BM causing tumors: NSCLC, melanoma and breast cancer.Expert opinion: High intracranial efficacy was observed for several next-generation tyrosine kinase inhibitors as well as immune checkpoint inhibitors, especially in patients with asymptomatic disease. Ongoing discussions addressed the need for local therapies in patients with asymptomatic BM and the availability of systemic therapy with high intracranial efficacy. Further BM-specific studies as well as BM-specific endpoints in registered trials are needed to define the role of systemic monotherapies in patients with BM.

The different central nervous system efficacy among gefitinib, erlotinib and afatinib in patients with epidermal growth factor receptor mutation-positive non-small cell lung cancer

Background

Brain metastasis is common in non-small cell lung cancer (NSCLC) and has an even higher incidence in epidermal growth factor receptor (EGFR)-mutant cancers. Although EGFR tyrosine kinase inhibitors (TKIs) are effective against brain metastases, it is unknown which first- or second-generation EGFR TKI is most effective.

Methods

Patients treated with first-line gefitinib, erlotinib, or afatinib for advanced EGFR-mutant NSCLC were included. The efficacy against brain metastasis was evaluated by comparing the response rates of measurable and non-irradiated brain metastases, central nervous system progression-free survival (CNS-PFS), and the cumulative incidence of CNS failure.

Results

Among the 559 patients who received EGFR-TKIs (gefitinib, n=299; erlotinib, n=93; afatinib, n=167), 198 had initial brain metastasis before starting EGFR-TKIs. The CNS response rates of gefitinib, erlotinib, and afatinib were 64.7%, 68.2%, and 72.9%, respectively (P=0.78). In the overall study population, irrespective of initial CNS metastasis, the median CNS-PFS was 17.3 months for gefitinib, 12.4 months for erlotinib, and 23.3 months for afatinib (P<0.001). In multivariate analysis for CNS-PFS, the hazard ratio (HR) of afatinib was 0.63 (95% CI, 0.47–0.83) compared with gefitinib or erlotinib. In the competing risk analysis for cumulative incidence of CNS failure, afatinib showed a lower cumulative incidence of CNS failure compared with gefitinib or erlotinib after adjusting for both EGFR mutation type and preexisting CNS metastases (HR 0.51, 95% CI, 0.34–0.75, P=0.0007).

Conclusions

Through there are some limitation as a retrospective study, afatinib showed similar CNS response rates, superior CNS-PFS and cumulative incidence of CNS failure, compared with gefitinib or erlotinib