Efficacy of the irreversible ErbB family blocker afatinib in epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI)-pretreated non-small-cell lung cancer patients with brain metastases or leptomeningeal disease

Phase II Trial of Afatinib in Patients With EGFR-Mutated Solid Tumors Excluding Lung Cancer: Results From NCI-MATCH ECOG-ACRIN Trial (EAY131) Subprotocol A

PURPOSE

National Cancer Institute-Molecular Analysis for Therapy Choice (NCI-MATCH) was a multicohort phase 2 trial that assigned patients with advanced pretreated cancers to molecularly targeted therapies on the basis of tumor genomic testing. NCI-MATCH Arm A evaluated afatinib, an EGFR tyrosine kinase inhibitor (TKI) approved for advanced non-small cell lung cancer, in patients with tumors other than lung cancer harboring EGFR mutations.

METHODS

Patients with advanced pretreated cancers other than lung cancer found to have selected actionable EGFR mutations were offered participation in Arm A. Previous therapy with an EGFR TKI was not allowed. Patients received afatinib 40 mg once daily continuously until disease progression or unacceptable toxicity. The primary end point was objective response rate (ORR). Secondary end points included progression-free survival (PFS), 6-month PFS, and overall survival (OS).

RESULTS

Seventeen patients received protocol therapy. Tumor types included glioblastoma multiforme (GBM) (13), gliosarcoma (1), adenocarcinoma not otherwise specified (NOS) (2), and adenosquamous carcinoma of the breast (1). Fifty-nine percent of patients received ≥2 lines of previous therapy. The ORR was 11.8% (90% CI, 2.1 to 32.6), with one complete response lasting 16.4 months (GBM harboring a rare exon 18 EGFR-SEPT14 fusion) and one partial response lasting 12.8 months (adenocarcinoma NOS with the classic EGFR mutation, p.Glu746_Ala750del). Three patients had stable disease. The 6-month PFS was 15% (90% CI, 0 to 30.7); the median OS was 9 months (90% CI, 4.6 to 14.0). Rash and diarrhea were the most common toxicities.

CONCLUSION

Afatinib had modest activity in a cohort of patients with heavily pretreated cancer with advanced nonlung, EGFR-mutated tumors, but the trial's primary end point was not met. Further evaluation of afatinib in GBM with EGFR exon 18 fusions may be of interest.

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.

Osimertinib is associated with improved outcomes in pre-treated non-small cell lung cancer leptomeningeal metastases: A systematic review and meta-analysiss

Purpose

Leptomeningeal metastasis (LM) is a severe complication of non-small cell lung cancer (NSCLC). In patients with NSCLC LM harboring epidermal growth factor receptor (EGFR) mutations, osimertinib is favored over alternative EGFR tyrosine kinase inhibitors (TKIs). However, the efficacy of osimertinib relative to other EGFR-TKIs is not well established for patients with LM. We aimed to compare the efficacy of EGFR-TKIs in EGFR-mutated NSCLC LM.

Methods

This systematic review and meta-analysis performed according to PRISMA guidelines included studies of adult patients with EGFR-mutated NSCLC and a diagnosis of LM who received an EGFR-TKI for the treatment of LM. We searched Medline ALL, Embase, Cochrane Central Register of Controlled Trials, Scopus, and Web of Science Core Collection. The evaluation of biases was done by using the Ottawa-Newscastle scale. The hazard ratio was used as the parameter of interest for overall survival (OS) and central nervous system-specific progression-free survival (PFS).

Results

128 publications were included with 243 patients and 282 lines of EGFR-TKI for NSCLC LM that met inclusion criteria. The median PFS in patients receiving any EGFR-TKI was 9.1 months, and the median OS was 14.5 months. In univariate analyses of the entire cohort, osimertinib treatment demonstrated significantly prolonged PFS, but not OS, compared to other EGFR-TKIs. Osimertinib demonstrated significantly prolonged PFS and OS in the subset of patients who were previously treated with EGFR-TKIs, but not in EGFR-TKI naïve patients.

Conclusion

Osimertinib is associated with improved outcomes compared to other EGFR-TKIs, particularly in patients previously treated with EGFR-TKIs. An important limitation is that most patients were derived from retrospective reports. These results highlight the need for prospective studies for this difficult-to-treat patient population.

Cerebrospinal fluid ctDNA testing shows an advantage over plasma ctDNA testing in advanced non-small cell lung cancer patients with brain metastases

Background

Brain metastases (BM), including brain parenchyma metastases (BPM) and leptomeningeal metastases (LM), are devastating metastatic complications in advanced cancer patients. Next-generation sequencing (NGS) is emerging as a new promising tool for profiling cancer mutation, which could facilitate the diagnosis of cancer. This retrospective study aimed to investigate the molecular genetic characteristics of non-small cell lung cancer (NSCLC) patients with BPM and LM using NGS.

Methods

Cerebrospinal fluid (CSF) samples and paired plasma samples were collected from 37 patients of NSCLC-BM. We profiled genetic mutation characteristics using NGS from NSCLC-BM by comparing CSF circulating tumour DNA (ctDNA) with plasma ctDNA and primary tumour tissues.

Results

Among the 37 patients with NSCLC-BM, 28 patients had LM with or without BPM, while 9 patients only had BPM. Driver and drug-resistant mutations in primary tumours with LM included: EGFR L858R (10, 35.7%), EGFR 19del (6, 21.4%), EGFR L858R+MET (1, 3.6%), EGFR L858R+S768I (1, 3.6%), ALK (2, 7.1%), ROS1 (1, 3.6%), negative (5, 17.9%), and unknown (2, 7.1%). In patients with NSCLC-LM, the detection rate and abundance of ctDNA in the CSF were significantly higher than those in paired plasma. The main driver mutations of NSCLC-LM remained highly consistent with those of the primary tumours, along with other unique mutations. Circulating tumour DNA was negative in the CSF samples of BPM patients. Patients with BMP had a higher ratio of EGFR 19del than L858R mutation (55.6% vs 11.1.%), whereas NSCLC patients with LM had a higher ratio of EGFR L858R than 19del mutation (50.0% vs 25.0%). Most patients with positive plasma ctDNA results were male (p = 0.058) and in an unstable state (p = 0.003).

Conclusion

Our study indicated that the CSF ctDNA detected by NGS may reflect the molecular characteristics and heterogeneity of NSCLC-LM. Timely screening of patients with NSCLC for CSF ctDNA, especially for patients with positive plasma ctDNA, may facilitate the early detection of LM. Furthermore, patients with the EGFR 19del may have a higher risk of developing BPM.

A phase I dose-escalation study of pulsatile afatinib in patients with recurrent or progressive brain cancer

Background

Afatinib (BIBW2992; Gilotrif®) is a selective and irreversible inhibitor of the epidermal growth factor receptor (ErbB; EGFR) family. It inhibits EGFR, HER2, and HER4 phosphorylation, resulting in tumor growth inhibition and regression. This phase I dose-escalation trial of pulsatile afatinib examined the safety, drug penetration into the central nervous system, preliminary antitumor activity, and recommended phase II dose in patients with progressive or recurrent brain cancers.

Methods

Afatinib was taken orally once every 4 days or once every 7 days depending on dose cohort, until disease progression or unacceptable toxicity.

Results

A total of 24 patients received the investigational agent and were evaluable for safety analyses, and 21 patients were evaluable for efficacy. Dosing was administered at 80 mg every 4 days, 120 mg every 4 days, 180 mg every 4 days, or 280 mg every 7 days. A recommended phase II dose of pulsatile afatinib was established at 280 mg every 7 days as there were no dose-limiting toxicities in any of the dosing cohorts and all toxicities were deemed manageable. The most common drug-related toxicities were diarrhea, rash, nausea, vomiting, fatigue, stomatitis, pruritus, and limb edema. Out of the 21 patients evaluable for efficacy, 2 patients (9.5%) exhibited partial response based on Response Assessment in Neuro-Oncology criteria and disease stabilization was seen in 3 patients (14.3%).

Conclusions

Afatinib taken orally was safe and well-tolerated up to 280 mg every 7 days in brain cancer patients.

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.

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.

On-DNA Morita-Baylis-Hillman Reaction: Accessing Targeted Covalent Inhibitor Motifs in DNA-Encoded Libraries

We herein present the first application of the on-DNA Morita-Baylis-Hillman (MBH) reaction for the creation of pharmaceutically relevant targeted covalent inhibitors (TCIs) with an α-hydroxyl Michael acceptor motif. Adapting a DNA-compatible organocatalytic process, this MBH reaction for covalent selection-capable DNA encoded library (DEL) synthesis grants access to densely functionalized and versatile precursors to explore novel chemical space for molecule recognition in drug discovery. Most importantly, this methodology sheds light on potentially unexpected reaction outcomes of the MBH reaction.

Synthesis of New Derivatives of Benzylidinemalononitrile and Ethyl 2-Cyano-3-phenylacrylate: In Silico Anticancer Evaluation

In this study, microwave-assisted Knoevenagel condensation was used to produce two novel series of derivatives (1-6) from benzylidenemalononitrile and ethyl 2-cyano-3-phenylacrylate. The synthesized compounds were characterized using Fourier transform infrared (FT-IR) and ¹H NMR spectroscopies. The pharmacodynamics, toxicity profiles, and biological activities of the compounds were evaluated through an in silico study using prediction of activity spectra for substances (PASS) and Absorption, Distribution, Metabolism, Excretion, and Toxicity (ADMET) studies. According to the PASS prediction results, compounds 1-6 showed greater antineoplastic potency for breast cancer than other types of cancer. Molecular docking was employed to investigate the binding mode and interaction sites of the derivatives (1-6) with three human cancer targets (HER2, EGFR, and human FPPS), and the protein-ligand interactions of these derivatives were compared to those reference standards Tyrphostin 1 (AG9) and Tyrphostin 23 (A23). Compound 3 showed a stronger effect on two cell lines (HER2 and FPPS) than the reference drugs. A 20 ns molecular dynamics (MD) simulation was also conducted to examine the ligand's behavior at the active binding site of the modeled protein, utilizing the lowest docking energy obtained from the molecular docking study. Enthalpies (ΔH), Gibbs free energies (ΔG), entropies (ΔS), and frontier molecular orbital parameters (highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) gap, hardness, and softness) were calculated to confirm the thermodynamic stability of all derivatives. The consistent results obtained from the in silico studies suggest that compound 3 has potential as a new anticancer and antiparasitic drug. Further research is required to validate its efficacy.

Clinical Outcomes of Afatinib Versus Osimertinib in Patients With Non-Small Cell Lung Cancer With Uncommon EGFR Mutations: A Pooled Analysis

BACKGROUND

The purpose of this analysis was to investigate the effectiveness of afatinib compared to that of osimertinib in patients with non-small cell lung cancer (NSCLC) who harbored uncommon epidermal growth factor receptor (EGFR) mutations.

METHODS

A PubMed database-based literature review was conducted to retrieve related studies. Patients harboring EGFR mutations besides the deletion in exon 19 (19del) and point mutation of L858R were included in this analysis. The primary outcome events were the objective response rate (ORR) and progression-free survival (PFS). Propensity score matching (PSM) at a ratio of 1:1 was used between afatinib and osimertinib groups to control the confounding factors. Uncommon EGFR mutations were categorized into 4 groups: insertion in exon 20 (ex20ins), non-ex20ins single uncommon EGFR mutations, compound EGFR mutations that with 19del or L858R, and compound EGFR mutations without 19del or L858R.

RESULTS

After PSM, 71 patients in either the afatinib or osimertinib group were matched. The afatinib group had an ORR of 60.6%, slightly higher than the osimertinib group's (50.3%), the difference was not statistically significant (P = .610). However, the afatinib group showed a significantly superior PFS benefit than the osimertinib group (11.0 vs. 7.0 months, P = .044). In addition, patients harboring non-ex20ins single uncommon EGFR mutations yield the best ORR and PFS, following treatment of either afatinib (ORR: 76.7%, mPFS: 14.1 months) or osimertinib (ORR: 68.8%, mPFS: 15.1 months). Moreover, there was no significant difference in terms of ORR or PFS between the cohort of patients treated with afatinib or osimertinib, regardless of whether or not the patients had brain metastases.

CONCLUSIONS

Both afatinib and osimertinib displayed favorable clinical activities toward uncommon EGFR mutations. Afatinib showed a more profound and durable PFS benefit than osimertinib, although no efficacy advantage was observed.

Upfront Advanced Radiotherapy and New Drugs for NSCLC Patients with Synchronous Brain Metastases: Is the Juice Worth the Squeeze? A Real-World Analysis from Lombardy, Italy

AIM

Healthcare administrative databases represent a valuable source for real-life data analysis. The primary aim of this study is to compare effectiveness and cost profile in non-small-cell lung cancer (NSCLC) patients harboring synchronous brain metastases (BMs) who received non-chemo first-line systemic therapy with or without advanced radiotherapy (aRT).

METHODS

Diagnostic ICD-9-CM codes were used for identifying all patients with a new diagnosis of lung cancer between 2012 and 2019. Among these, patients who had started a first-line systemic treatment with either TKIs or pembrolizumab, alone or in combination with intensity-modulated or stereotactic RT, were selected. Clinical outcomes investigated included overall survival (OS), progression-free survival (PFS), and time-to-treatment failure (TTF). The cost outcome was defined as the average per capita cumulative healthcare direct costs of the treatment, including all inpatient and outpatient costs.

RESULTS

The final cohort included 177 patients, of whom 58 were treated with systemic treatment plus aRT (STRT) and 119 with systemic treatment alone. The addition of aRT to systemic treatment was associated with a significantly better OS (p = 0.020) and PFS (p = 0.041) than systemic therapy alone. The ICER (incremental cost-effectiveness ratio) value indicated an average cost of €3792 for each month of survival after STRT treatment and confirmed clinical effectiveness but higher healthcare costs.

CONCLUSIONS

This real-world study suggests that upfront aRT for NCLSC patients with synchronous BMs represents a valid treatment strategy, boosting the efficacy of novel and emerging drug classes with sustainable costs for the health service.

TRANSLATIONAL RELEVANCE

The present real-world study reports that the use of upfront advanced radiotherapyaRT and new-generation systemic agents, such as TKIs and pembrolizumab, may have higher oncological control and an improved cost-effectiveness profile than the use of new-generation systemic agents alone in NCLSC patients with synchronous brain metastases. Acquired evidence can also be used to inform policymakers that adding advanced radiotherapy results is a sustainable cost for the health service. Since approximately 50% of patients do not meet RCT inclusion criteria, a significant proportion of them is receiving treatment that is not evidence-informed; therefore, these results warrant further studies to identify the best radiotherapy timing and possible dose escalation approaches to improving treatment efficacy in patient subgroups not typically represented in randomized controlled trials.

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.

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.

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.

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 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.

Targeting Acquired and Intrinsic Resistance Mechanisms in Epidermal Growth Factor Receptor Mutant Non-Small-Cell Lung Cancer

Over the past 2 decades, rapid advances in molecular profiling and the development of targeted therapies have dramatically improved the clinical course of advanced non-small-cell lung cancer (NSCLC). Mutations in the epidermal growth factor receptor (EGFR) gene are found in about a third of patients with advanced NSCLC, and the approval of first-generation EGFR targeted kinase inhibitors significantly improved survival when compared with platinum-based doublet chemotherapy (PBC), the previous standard of care. Inevitably, selective pressure from first-generation EGFR inhibitors led to acquired resistance mechanisms, such as the T790M mutation. The advent of third-generation EGFR inhibitors (e.g., osimertinib) successfully overcame the T790M resistance mechanism, and osimertinib subsequently became the first-line therapy for EGFR mutant NSCLC. Currently, research in EGFR mutant NSCLC is primarily focused on targeting resistance mechanisms to osimertinib. Over the past several years, many important acquired and intrinsic mechanisms of resistance to osimertinib have been identified. Acquired resistance mechanisms include C797X, mesenchymal epithelial transition factor (MET) amplification, HER2/HER3 amplification, phosphoinositide 3-kinase (PI3K) pathway mutations, RAS/mitogen-activated protein kinase (MAPK) pathway mutations, cell-cycle gene alterations, oncogenic fusions, and histologic transformations. An important intrinsic resistance mechanism to osimertinib is the EGFR exon 20 insertion mutation, which is sensitive to the newly Food and Drug Administration (FDA)-approved tyrosine kinase inhibitor mobocertinib and the EGFR/MET bispecific antibody amivantamab. This review article aims to (1) summarize the advances in the treatment of EGFR mutant NSCLC, (2) delineate known resistance mechanisms to the current first-line therapy, osimertinib, and (3) describe the development of targeted drugs that aim to overcome these resistance mechanisms.

Epidermal growth factor receptor-targeted therapy for the treatment of non-small cell lung cancer: A review of phase II and III trials

INTRODUCTION

EGFR is one of the most common driver gene mutations in lung cancer. EGFR-TKI monotherapy and EGFR-TKI combined with chemotherapy or anti-angiogenesis drugs have significantly prolonged the survival of patients with EGFR-mutant NSCLC. However, disease progression caused by acquired resistance to EGFR-TKIs is inevitable. And patients with EGFR exon 20ins showed limited efficacy to EGFR-TKIs.

AREAS COVERED

In this review, we initially evaluated the efficacy of existing treatments for EGFR-mutant NSCLC. Second, we reviewed the ongoing phase II and III clinical trials, provide the latest results, discuss the scientific rationale of these trials and the potential development issues.

EXPERT OPINION

The application of EGFR-TKIs has greatly changed the therapeutic strategies for advanced and resected NSCLC with EGFR mutations, and the 5-year OS rate for advanced NSCLC was close to 40%. The current research direction for the treatment of patients with EGFR mutations focuses on the following three aspects: uncommon EGFR mutation subtypes NSCLC, brain metastases, and EGFR TKI-based combination therapy. Future studies on EGFR-mutant NSCLC therapy will focus on overcoming EGFR-TKI-related resistance, preventing drug resistance in advance, and developing bispecific antibody drugs. ADCs may be the promising strategy for patients with acquired resistance to EGFR-TKIs.

Systematic Analysis of Stress Granule Regulators-Associated Molecular Subtypes Predicts Drug Response, Immune Response, and Prognosis in Non-Small Cell Lung Cancer

Lung cancer has the world’s second highest cancer incidence and second highest cancer-related mortality rate. However, the mechanism underlying non-small cell lung cancer (NSCLC) remained to be unclear. Overall, this study for the first time revealed Stress Granule Regulators were mutated and dysregulated in NSCLC samples by analyzing TCGA database. Moreover, three subtypes of NSCLC were identified based on the expression levels of Stress Granule Regulators. Patients in cluster 2 showed a higher survival rate than those in clusters 1 and 3. Bioinformatics analysis indicated the cell cycle, mTOR signaling pathway, EGFR signaling, PI3K/Akt signaling and DNA damage repair signaling were significantly related to molecular subtypes. Moreover, we performed a prediction analysis of the response to the inhibitors against the aforementioned signaling. Our results showed patients in C2 NSCLC had the highest sensitivity to MK.2206 (AKT.inhibitor) and Rapamycin (mTOR inhibitor). Patients in C3 NSCLC had the highest sensitivity for Temsirolimus (PI3K/mTOR signaling), BIBW2992 (EGFR signaling), Erlotinib (EGFR signaling), PD.0332991 (CDK4/6 inhibitor), CGP.60474 (CDK inhibitor), and Gefitinib (EGFR signaling). Moreover, our results showed patients in C1 NSCLC had the highest sensitivity to AKT.inhibitor, AZD6482 (PI3K inhibitor). To evaluate the response to immune therapy of different subtypes, we analyzed the tumor immune inflation, immune regulators expression, and TIDE score in different SG related subtypes. These results showed that C2 and C3 may be more sensitive to immune therapy. To better predict the prognosis of NSCLC, we analyzed the correlation between stress granule regulator expression and overall survival time in NSCLC and constructed a Stress Granule Score including EIF2S1, CTSG, EIF4G1, IGF2BP1, PABPC1 to predict the prognosis of NSCLC. Overall, this study for the first time uncovers the effect of stress particles on drug response, immune response, and prognosis, laying a new theoretical foundation for the NSCLC prognosis and treatment.

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.

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.

Anti-PD1 Therapy Plus Whole-Brain Radiation Therapy May Prolong PFS in Selected Non-Small Cell Lung Cancer Patients with Brain Metastases: A Retrospective Study

Background

Whole-brain radiotherapy (WBRT) remains an essential modality of treatment for brain metastases (BMs) derived from non-small cell lung cancer (NSCLC) patients and anti-PD-1 therapy has demonstrated intracranial responses in these patients. We aimed to evaluate if the combination of the two treatments could yield additive efficacy.

Methods

A retrospective review of our institution’s database was carried out to identify NSCLC patients with BMs who had been treated with anti-PD1 therapy and/or WBRT between 2015 and 2020. Patient characteristics, main outcomes, including progression-free survival (PFS) and overall survival (OS), and factors affecting these outcomes were analyzed. SPSS 24 was used for statistical analysis. Appropriate statistical tests were employed according to the type of data.

Results

Overall, 21 NSCLC BM patients were identified that had received WBRT. Of these, ten had been additionally treated with anti-PD1 therapy within 30 days of WBRT initiation. Median PFS was 3 (95% CI 0.8–5.1) months with WBRT alone versus 11 (95% CI 6.3–15.6) months with combined treatment. Risk of disease progression was 71% lower with the combined approach (HR 0.29, 95% CI 0.11–0.80; p=0.016). A trend toward improved OS was also observed with the combined approach (HR 0.33, 95% CI 0.08–1.12; p=0.107). Concurrent treatment (p=0.028) and male sex (p=0.052) were associated with improved PFS, while OS was associated only with age (p=0.02).

Conclusion

Concurrent WBRT and anti-PD1 therapy may delay progression and improve survival in BM patients with confirmed EGFR- and ALK-negative NSCLC histology. Prospective studies are warranted to validate and elucidate on the additive effect of the two modalities.

Afatinib and radiotherapy, with or without temozolomide, in patients with newly diagnosed glioblastoma: results of a phase I trial

Background

Glioblastoma multiforme (GBM) is the most common primary malignant brain tumor in adults. Amplification or overexpression of the epidermal growth factor receptor gene, part of the ErbB family, occur in approximately 40% and 60% of patients with GBM, respectively. We present data from a dose-finding study of the ErbB inhibitor afatinib in combination with radiotherapy (RT), with or without temozolomide (TMZ), in patients with GBM.

Methods

This was a phase I, open-label, 3 + 3 dose-escalation trial in patients with newly-diagnosed, histologically-confirmed grade 4 malignant glioma and proven O⁶-methylguanine-DNA methyltransferase gene promoter methylation status. The primary endpoint was the maximum tolerated dose (MTD) of continuous daily afatinib when given in combination with RT, with (regimen M) or without (regimen U) concomitant TMZ treatment.

Results

Fifty-five patients were enrolled; 36 received ≥ 1 dose of trial medication (regimen M, n = 20, regimen U, n = 16). Afatinib was discontinued by all patients during the study. Reasons for afatinib discontinuation (regimen M/U) included disease progression (45%/50%), dose-limiting toxicity (10%/0%), and other adverse events (AEs; 35%/38%). The most frequently reported AEs with either regimen were diarrhea and rash, with no new safety signals identified. The MTD was determined as afatinib 30 mg in combination with daily TMZ and RT, and afatinib 40 mg in combination with RT alone.

Conclusions

This study identified the MTD for afatinib in combination with RT, with and without TMZ, in patients with GBM. Further studies of afatinib in patients with GBM are warranted and should be based on appropriate biomarker-based preselection.

Trial registration

NCT00977431 (first posted September 15, 2009).

Supplementary Information

The online version contains supplementary material available at 10.1007/s11060-021-03877-6.

Craniospinal irradiation in the treatment of chemotherapy refractory leptomeningeal metastasis from breast cancer: A case report

Background

Leptomeningeal carcinomatosis is a relatively uncommon complication of solid tumors that is associated with significant morbidity and mortality. Prognosis is typically weeks to months and the neurologic complications of this disease can significantly affect quality of life. The role of craniospinal irradiation is unclear as evidence exploring this treatment option is limited. Despite lack of evidence, its use has decreased due to its associated acute toxicities and newer intrathecal alternatives.

Case

Here we report the case of a 50‐year‐old patient who received craniospinal irradiation for chemotherapy‐refractory leptomeningeal disease, with survival well beyond the median and good quality of life for the majority of that time.

Conclusion

This patient's remarkable survival and performance after treatment suggests that craniospinal irradiation could be considered more frequently in the treatment of leptomeningeal metastases. To our knowledge, this is the first case with significant survival following craniospinal irradiation for chemotherapy refractory disease presented. Further study on the use of craniospinal irradiation to treat leptomeningeal metastasis is recommended.

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.

Sophoraflavanone G Resensitizes ABCG2-Overexpressing Multidrug-Resistant Non-Small-Cell Lung Cancer Cells to Chemotherapeutic Drugs

Elevated expression of the ATP-binding cassette (ABC) drug transporter ABCG2 in cancer cells contributes to the development of the multidrug resistance phenotype in patients with advanced non-small-cell lung cancer (NSCLC). Due to the lack of U.S. Food and Drug Administration (FDA)-approved synthetic inhibitors of ABCG2, significant efforts have been invested in discovering bioactive compounds of plant origin that are capable of reversing ABCG2-mediated multidrug resistance in cancer cells. Sophoraflavanone G (SFG), a phytoncide isolated from the plant species Sophora flavescens, is known to possess a wide spectrum of pharmacological activities, including antibacterial, anti-inflammatory, antimalarial, and antiproliferative effects. In the present study, the chemosensitizing effect of SFG in ABCG2-overexpressing NSCLC cells was investigated. Experimental results demonstrate that at subtoxic concentrations SFG significantly reversed ABCG2-mediated multidrug resistance in a concentration-dependent manner. Additional biochemical data and in silico docking analysis of SFG to the inward-open conformation of human ABCG2 indicate that SFG inhibited the drug transport function of ABCG2 by interacting with residues within the transmembrane substrate-binding pocket of ABCG2. Collectively, these findings provide evidence that SFG has the potential to be further tested as an effective inhibitor of ABCG2 to improve the efficacy of therapeutic drugs in patients with advanced NSCLC.

Association of EGFR Tyrosine Kinase Inhibitor Treatment With Progression-Free Survival Among Taiwanese Patients With Advanced Lung Adenocarcinoma and EGFR Mutation

Background: There is limited data on the relative survival rate of first-line therapy of gefitinib, erlotinib (first-generation epidermal growth factor receptor-tyrosine kinase inhibitor [EGFR-TKI]), and afatinib (second-generation EGFR-TKI) in patients with EGFR-mutated advanced lung adenocarcinoma in real-world data, especially in the Asian population. This study aimed to compare the relative survival rate of gefitinib, erlotinib, and afatinib in patients with EGFR-mutated advanced lung adenocarcinoma by real-world data in Taiwan. Methods: This retrospective cohort population-based study included untreated adult patients diagnosed with advanced lung adenocarcinoma who were identified in the Taiwan National Health Insurance Research Database between 2014 and 2017. The date of EGFR-mutated advanced lung adenocarcinoma diagnosis was referred as index date. This outcome evaluated overall survival (OS) and time to treatment failure (TTF) between gefitinib, erlotinib, and afatinib. Switching EGFR-TKIs or chemotherapy and new development of brain metastases were proxies of TTF. Estimated relative treatment effects on OS and TTF among EGFR-TKIs were adjusted by inverse probability of treatment weighting (IPTW) in Cox proportional hazards model. Propensity score (PS) matched pair analyses were performed as sensitivity analyses. Results: The study cohort included 3,695 patients initiated with gefitinib, 3,310 with erlotinib, and 3,041 with afatinib. The mean age among the three treatment groups was 70.4 (±11.6), 66.8 (±11.6), and 64.3 (±11.4) years, and the female percentage was 70.4, 58.6, and 57.7%, respectively. Afatinib showed longer median OS than gefitinib (23.9 vs. 21.3 months; adjusted hazard ratio (aHR), 0.87; p < 0.001) and erlotinib (23.9 vs. 21.8 months; aHR, 0.87; p = 0.001). Consistent results were observed with TTF outcomes. For patients with brain metastases at diagnosis, afatinib showed similar OS with erlotinib (p = 0.917) but superior to gefitinib (p = 0.028). PS matching had similar results with IPTW adjustment in the study population. Conclusion: Afatinib as first-line therapy had better survival outcomes for EGFR-mutated advanced lung adenocarcinoma than gefitinib and erlotinib in the Taiwan population. Both erlotinib and afatinib demonstrated superior treatment effect in patients with initial brain metastases than gefitinib.

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.

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.

Lipid polymeric nanoparticles modified with tight junction-modulating peptides promote afatinib delivery across a blood–brain barrier model

Background

Brain metastases from non-small cell lung cancer (NSCLC) remain one of the most challenging malignancies. Afatinib (Afa) is an orally administered irreversible ErbB family blocker approved for epidermal growth factor receptor (EGFR)-mutated NSCLC. However, the incidence of brain metastases in patients with NSCLC and EGFR mutation is high. One of the major obstacles in the treatment of brain metastases is to transport drugs across the blood–brain barrier (BBB). A lipid polymeric nanoparticle (LPN) modified with a tight junction-modulating peptide is a potential formulation to deliver therapeutics across the BBB. FD7 and CCD are short peptides that perturb the tight junctions (TJs) of the BBB. In this study, the use of LPN modified with FD7 or CCD as a delivery platform was explored to enhance Afa delivery across the BBB model of mouse brain-derived endothelial bEnd.3 cells.

Results

Our findings revealed that Afa/LPN-FD7 and Afa/LPN-CCD exhibited a homogeneous shape, a uniform nano-scaled particle size, and a sustained-release profile. FD7, CCD, Afa/LPN-FD7, and Afa/LPN-CCD did not cause a significant cytotoxic effect on bEnd.3 cells. Afa/LPN-FD7 and Afa/LPN-CCD across the bEnd.3 cells enhanced the cytotoxicity of Afa on human lung adenocarcinoma PC9 cells. FD7 and CCD-modulated TJ proteins, such as claudin 5 and ZO-1, reduced transendothelial electrical resistance, and increased the permeability of paracellular markers across the bEnd.3 cells. Afa/LPN-FD7 and Afa/LPN-CCD were also partially transported through clathrin- and caveolae-mediated transcytosis, revealing the effective activation of paracellular and transcellular pathways to facilitate Afa delivery across the BBB and cytotoxicity of Afa on PC9 cells.

Conclusion

TJ-modulating peptide-modified LPN could be a prospective platform for the delivery of chemotherapeutics across the BBB to the brain for the potential treatment of the BM of NSCLC.

Overcoming therapy resistance in EGFR-mutant lung cancer

Tyrosine kinase inhibitors (TKIs) have dramatically changed the clinical prospects of patients with non-small cell lung cancer harboring epidermal growth factor receptor (EGFR)-activating mutations. Despite prolonged disease control and high tumor response rates, all patients eventually progress on EGFR TKI treatment. Here, we review the mechanisms of acquired EGFR TKI resistance, the methods for monitoring its appearance, as well as current and future efforts to define treatment strategies to overcome resistance.

Treatment Options of First-Line Tyrosine Kinase Inhibitors and Subsequent Systemic Chemotherapy Agents for Advanced EGFR Mutant Lung Adenocarcinoma Patients: Implications From Taiwan Cancer Registry Cohort

Objectives

Large-scale, population-based real-world studies on the treatment outcomes of first-line tyrosine kinase inhibitors (TKIs) and subsequent systemic chemotherapy agents for lung adenocarcinoma (with activating epidermal growth factor receptor [EGFR] mutations) remain limited.

Materials and Methods

From March 2014 to December 2016, patients with advanced lung adenocarcinoma, identified from the Taiwan Cancer Registry were included in this study if they received any of the three TKIs as first-line treatment. The primary outcome was overall survival (OS). The secondary outcome was time-to-treatment discontinuation (TTD).

Results

A total of 4,889 patients (median age: 67 years and two-thirds with distant metastasis) were recruited (1,778 gefitinib, 1,599 erlotinib, and 1,512 afatinib users). A 1:1 propensity score (PS)-matched cohorts of 1,228 afatinib/erlotinib and 1054 afatinib/gefitinib was created. After PS matching, it was found that afatinib was not associated with better OS (afatinib vs. erlotinib, HR: 0.96, 95% CI: 0.86–1.07; afatinib vs. gefitinib, HR: 0.91, 95% CI: 0.81–1.02). In the subgroup analysis, afatinib demonstrated a survival benefit in patients with active smoking (afatinib vs. erlotinib, HR: 0.69, 95% CI: 0.51–0.93; afatinib vs. gefitinib, HR: 0.67, 95% CI: 0.48–0.94) and ECOG > 1 (afatinib vs. erlotinib, HR: 0.79, 95% CI: 0.63–0.99; afatinib vs. gefitinib, HR: 0.78, 95% CI: 0.62–0.98). A total of 41.1% (n = 1992) of first-line TKI users received subsequent chemotherapy. Among the three TKI groups, pemetrexed usage was associated with better OS compared with other chemotherapy agents, with the exception of gemcitabine in the afatinib and gefitinib groups. Pemetrexed and gemcitabine had the longest TTD of 3–4 months.

Conclusions

Among patients with EGFR mutant lung adenocarcinoma, afatinib use may not provide longer OS compared with first-generation TKIs. Afatinib may be preferably considered among patients with active smoking and should not be withheld among those with worse performance status. With 40% of patients receiving subsequent chemotherapy, pemetrexed may be the preferred agent, while gemcitabine can be a reasonable alternative.

A real-world study in advanced non-small cell lung cancer with de novo brain metastasis

Brain metastases are the major cause of life-expectancy shortened for patients with lung cancer. The prognostic value of EGFR mutation subtypes and survival benefit of EGFR-tyrosine kinase inhibitors (TKIs) in advanced non-small cell lung cancer (NSCLC) patients with de novo brain metastasis is still not clear. Here, we present a real-world study nation-wide focusing on the prognostic value of genomic and therapeutic factors in overall survival (OS) of those patients. We enrolled a total of 233 patients diagnosed with advanced NSCLC and de novo BM from multi-medical centers across China. The enrolled patients were divided into 4 groups, including EGFR 19del, EGFR L858R, EGFR wild-type, and EGFR unknown groups. The median OS of patients with EGFR mutations and all patients were 29.0 and 25.0 months, respectively. There was significant difference in OS of patients among EGFR 19del (n=76), EGFR L858R (n=94), EGFR wild-type (n=46) and EGFR unknown (n=17) groups (30.5 vs 27.5 vs 16.0 vs 25.0, P=0.025). Patients treated by icotinib showed better OS than gefitinib and erlotinib (31.0 vs 25.5 vs 26.5, P=0.02). There was a difference in OS of patients received the whole-brain radiotherapy (WBRT), stereotactic radiosurgery (SRS), or WBRT+SRS (20.0 vs 31.0 vs 30.0 months, P<0.001), respectively. In multivariate analysis, patients treated with icotinib had superior iPFS benefit than gefitinib and erlotinib (HR=0.86[95%CI (0.74-1.0)], P=0.04). Besides, the histology of non-adenocarcinomas, the number of BM (>3), and extracranial metastases status could have an independent negative impact on the OS of all patients (P<0.001). EGFR mutant NSCLC patients with de novo BM had a better OS than patients with EGFR wild type. Patients treated with icotinib had longer iPFS than gefitinib and erlotinib but not in OS. Non-adenocarcinomas, number of BM (>3) and extracranial metastases were independent negative prognostic factors in iPFS and OS of all patients. Prospective clinical trials are warranted to explore more effective multimodality in this population.

Development of EGFR TKIs and Options to Manage Resistance of Third-Generation EGFR TKI Osimertinib: Conventional Ways and Immune Checkpoint Inhibitors

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs) have been first-line therapy in the treatment of non-small cell lung cancer (NSCLC) harboring EGFR sensitive mutations. Progression inevitably happens after 10–14 months of first- or second-generation EGFR TKIs treatment for acquired resistance. Owing to the successful identification of EGFR T790M, third-generation EGFR TKIs such as osimertinib were developed to target such resistance mutation. Nowadays, osimertinib has shown its efficacy both in first-line and second-line after resistance to previous generations of TKI treatment of EGFR-mutant NSCLC. However, drug resistance also emerges on third-generation EGFR TKIs. Multiple mechanisms of acquired resistance have been identified, and some novel strategies were reported to overcome third-generation TKI resistance. Immune checkpoint inhibitors (ICIs) have dramatically changed the prognosis of selected patients. For patients with EGFR-addicted metastatic NSCLC, ICIs have also revealed a potential role. In this review, we will take stock of mechanisms of acquired resistance to third-generation TKIs and discuss current challenges and future perspectives in clinical practice.

Recent Advances on the Role of EGFR Tyrosine Kinase Inhibitors in the Management of NSCLC With Uncommon, Non Exon 20 Insertions, EGFR Mutations

The first-line treatment of choice for patients with EGFR mutation-positive NSCLC is an EGFR tyrosine kinase inhibitor (TKI), of which five as follows are predominantly available in practice: gefitinib, erlotinib, afatinib, dacomitinib, and osimertinib. Most prospective clinical trial data with these agents are limited to patients with the common activating and sensitizing EGFR mutations as follows: exon 19 deletions and exon 21 L858R point mutations. However, 10% to 20% of patients with NSCLC harbor uncommon EGFR mutations that have variable sensitivity to different EGFR TKIs. Owing to their molecular structures, afatinib, dacomitinib, and osimertinib have broader inhibitory profiles than the first-generation agents, gefitinib and erlotinib. Nevertheless, the paucity of prospective clinical data, the wide heterogeneity of uncommon mutations, and the existence of compound mutations in up to 25% of the cases complicate treatment decisions in this patient subgroup. Here, we collate the latest preclinical and clinical data regarding the activity of different TKIs against major uncommon EGFR mutations including compound mutations, but excluding exon 20 insertions which are generally insensitive to TKIs. On the basis of these data, we offer suggestions regarding treatment strategies for uncommon EGFR mutations. Moving forward, it will be important to include uncommon EGFR mutations in the first-line molecular analysis of all patients with adenocarcinoma of the lung, as this will help optimize patient outcomes according to their precise genotype.

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).

The new opportunities in medicinal chemistry of fourth-generation EGFR inhibitors to overcome C797S mutation

Epidermal growth factor receptor (EGFR) is a receptor for epithelial growth factor (EGF) cell proliferation and signaling, which is related to the inhibition of tumor cell proliferation, angiogenesis, tumor invasion, metastasis, and apoptosis. Thus, it has become an important target for the treatment of non-small cell lung cancer (NSCLC). The first to the third-generation EGFR inhibitors have demonstrated powerful efficacy and brought a prospect to patients. Unfortunately, after 9-15 months of treatment, they all developed resistance without exception. As for the resistance of third-generation inhibitors, no major breakthrough has been made in this field. In this review, we discussed the recent advances in medicinal chemistry of fourth-generation EGFR-TKIs, as well as further discussed the clinical challenges and future prospects of treating patients with EGFR mutations resistant to third-generation EGFR-TKIs.

Treating Choroidal Metastases and Improving Vision with Osimertinib in EGFR T790M-Mutated Lung Adenocarcinoma: A Case Report and Review of the Literature

A 41-year-old never-smoking female was diagnosed with epidermal growth factor receptor (EGFR)-mutated T2bN3M1b lung adenocarcinoma with axillary lymph nodes. She complained of blurred vision in the left eye (2/60) and was subsequently found to have a left choroidal metastasis. Treatment with tyrosine kinase inhibitor (TKI) erlotinib was started, and after 1 year of disease stability, she developed unsteadiness and worsening visual disturbance (1/60). Brain imaging showed 24 new brain metastases, which were treated with Gamma Knife stereotactic radiosurgery. An enlarging axillary lymph node was biopsied, which identified the T790M mutation, and she commenced the novel TKI osimertinib. Three weeks later, her choroidal lesion had regressed from 3.1 mm to 2.2 mm, and after 2 months of osimertinib, her visual acuity had improved to 6/9. At the last follow-up 8 months after initiation of osimertinib, her choroidal metastasis remains stable, and visual acuity has improved to 6/6. Evidence suggests that osimertinib's efficacy in treating cerebral metastases is superior to that of chemotherapy and other EGFR-TKIs (gefitinib and erlotinib); however, the literature is sparse with regards to the use of osimertinib for the treatment of intraocular disease. In this case, the need for intense daily radiation treatment with its associated toxicities was negated, and as such we propose that osimertinib may be a promising treatment for choroidal metastasis secondary to EGFR-mutated lung adenocarcinoma.

Effective Treatment With Afatinib of Lung Adenocarcinoma With Leptomeningeal Metastasis Harboring the Exon 18 p.G719A Mutation in the EGFR Gene Was Detected in Cerebrospinal Fluid: A Case Report

Background: In patients with lung adenocarcinoma and leptomeningeal metastases, it remains unknown whether non-classical mutations in the epidermal growth factor receptor (EGFR) gene can be detected in the cerebrospinal fluid (CSF) and how it may be used to design directed therapy.

Methods: On April 18, 2018, the Interventional Department of Tianjin Huanhu Hospital admitted a 34-years-old male patient with lung adenocarcinoma and leptomeningeal metastasis. An emergency lateral ventriculoperitoneal shunt was performed to relieve the clinical symptoms of intracranial hypertension. Next-generation sequencing (NGS) of the CFS specimens revealed a mutation in EGFR exon 18 p.G719A, and afatinib was administered. Follow-up showed significantly relieved headache, with significantly reduced soft leptomeningeal abnormal enhancement as revealed by enhanced magnetic resonance imaging and significantly smaller tumors in the left lung by chest computed tomography. Carcinoembryonic antigens (CEAs) in cerebrospinal fluid and peripheral blood were significantly reduced. The patient responded well to afatinib, with mild adverse complications. The patient died on October 27, 2019 from respiratory failure as a result of lung infection unrelated to cancer progression. The overall survival (OS) using afatinib was 530 days.

Conclusion: CSF can be used as a liquid biopsy for NGS gene detection in patients with lung adenocarcinoma and leptomeningeal metastases. Afatinib exhibits a beneficial effect in patients with lung adenocarcinoma and leptomeningeal metastases harboring the EGFR exon 18 p.G719A mutation.

Erlotinib for Non-Small Cell Lung Cancer with Leptomeningeal Metastases: A Phase II Study (LOGIK1101)

LESSONS LEARNED

This phase II trial evaluated the efficacy of erlotinib for patients with non-small cell lung cancer with leptomeningeal metastasis. The 17 cerebrospinal fluid specimens that were available for epidermal growth factor receptor mutation analysis were all negative for the resistance-conferring T790M mutation. The cytological objective clearance rate was 30.0% (95% confidence interval: 11.9%-54.3%). The median time to progression was 2.2 months. The rate of cerebrospinal fluid penetration among these patients was equivalent to those in previous reports regarding leptomeningeal metastasis.

BACKGROUND

Leptomeningeal metastases (LM) occur in approximately 5% of patients with non-small cell lung cancer (NSCLC) and are associated with a poor prognosis. However, no prospective study has identified an active chemotherapeutic drug in this setting.

METHODS

Patients were considered eligible to receive erlotinib if they had NSCLC with cytologically confirmed LM. The objective cytological clearance rate, time to LM progression (TTP), overall survival (OS), quality of life outcomes, and pharmacokinetics were analyzed. This study was closed because of slow accrual at 21 of the intended 32 patients (66%).

RESULTS

Between December 2011 and May 2015, 21 patients (17 with activating epidermal growth factor receptor [EGFR] mutations) were enrolled. The 17 cerebrospinal fluid specimens available were all negative for the T790M mutation, which confers erlotinib resistance. The clearance rate was 30.0% (95% confidence interval [CI]: 11.9%-54.3%), the median TTP was 2.2 months, and the median OS was 3.4 months. Significantly longer TTP and OS times were observed in patients with mutant EGFR (p = .0113 and p < .0054, respectively). The mean cerebrospinal fluid penetration rate was 3.31% ± 0.77%. There was a good correlation between plasma and cerebrospinal fluid (CSF) concentrations, although there was no clear correlation between pharmacokinetic parameters and clinical outcome.

CONCLUSION

Erlotinib was active for LM and may be a treatment option for patients with EGFR-mutated NSCLC and LM.

Osimertinib Improves Overall Survival in Patients With EGFR-Mutated NSCLC With Leptomeningeal Metastases Regardless of T790M Mutational Status

INTRODUCTION

Osimertinib, a third-generation EGFR tyrosine kinase inhibitor, efficiently penetrates the blood-brain barrier. This study explored whether treatment with osimertinib leads to improved overall survival (OS) for patients with EGFR-mutated NSCLC with leptomeningeal metastases (LM) compared with those not treated with osimertinib.

METHODS

From October 2008 to October 2019, patients with EGFR-mutated NSCLC and cytologically confirmed LM were retrospectively analyzed for OS according to osimertinib treatment and T790M mutational status. The OS was defined as the time from the diagnosis of LM to death.

RESULTS

For the 351 patients with LM included in the analysis, the median OS (mOS) was 8.1 months (95% confidence interval [CI]: 7.2-9.0). T790M mutation was detected in 88 of 197 patients tested, and a total of 110 patients were treated with osimertinib after LM. No difference in mOS according to T790M mutational status (10.1 mo [95% CI: 4.31-15.82] versus 9.0 [95% CI: 6.81-11.21], p = 0.936) was found. Nevertheless, patients treated with osimertinib had a superior OS of 17.0 months (95% CI: 15.13-18.94) compared with those not treated with osimertinib who had a mOS of 5.5 months (95% CI: 4.34-6.63), regardless of T790M mutational status (hazard ratio: 0.36 [95% CI: 0.28-0.47], p < 0.001). This was also considerably longer even than the mOS of 8.7 months (95% CI: 7.01-10.39) of those who were never treated with osimertinib but had first- or second-generation EGFR tyrosine kinase inhibitors.

CONCLUSIONS

Osimertinib is a promising treatment option for EGFR-mutated NSCLC with LM regardless of T790M mutational status.

Efficacy and safety of afatinib for non-small-cell lung cancer: state-of-the-art and future perspectives

INTRODUCTION

Afatinib is a second-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, acting as an irreversible and multitarget blocker of ErbB family members. Afatinib is currently approved for advanced non-small-cell lung cancer (NSCLC) harboring common and uncommon sensitizing EGFR mutations and for squamous NSCLC patients progressing after first-line platinum-based chemotherapy.

AREAS COVERED

This review summarizes the efficacy and safety profile of afatinib compared with chemotherapy and other EGFR TKIs, in order to evaluate its characteristics and potential role in the increasingly complex treatment landscape of EGFR-mutant lung cancer. Future perspectives and innovative drug combinations are also discussed.

EXPERT OPINION

Afatinib has been demonstrated to improve efficacy and quality of life compared with chemotherapy with a managed toxicity profile. However, in recent years, the increasing availability of different treatment options for advanced EGFR-mutant NSCLC has made the current treatment scenario more complicated, with an increasing need of new and deeper scientific data. In this light, the identification and validation of potential clinicopathological and/or molecular predictors of benefit, as well as the clarification of resistance mechanisms, may help to clarify the most appropriate treatment strategies and sequences for EGFR-mutant patients.

Tyrosine Kinase Inhibitor Therapy for Brain Metastases in Non-Small-Cell Lung Cancer: A Primer for Radiologists

Treatment options for patients who develop brain metastases secondary to non-small-cell lung cancer have rapidly expanded in recent years. As a key adjunct to surgical and radiation therapy options, systemic therapies are now a critical component of the oncologic management of metastatic CNS disease in many patients with non-small-cell lung cancer. The aim of this review article was to provide a guide for radiologists, outlining the role of systemic therapies in metastatic non-small-cell lung cancer, with a focus on tyrosine kinase inhibitors. The critical role of the blood-brain barrier in the development of systemic therapies will be described. The final sections of this review will provide an overview of current imaging-based guidelines for therapy response. The utility of the Response Assessment in Neuro-Oncology criteria will be discussed, with a focus on how to use the response criteria in the assessment of patients treated with systemic and traditional therapies.