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

Molecular Mechanisms and Targeted Therapies Including Immunotherapy for Non-Small Cell Lung Cancer

Lung cancer is the leading cause of cancer death worldwide. Molecular targeted therapy has greatly advanced the field of treatment for non-small cell lung cancer (NSCLC), which accounts for the majority of lung cancers. Indeed, gefitinib, which was the first molecular targeted therapeutic agent, has actually doubled the survival time of NSCLC patients. Vigorous efforts of clinicians and researchers have revealed that lung cancer develops through the activating mutations of many driver genes including the epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK), c-ros oncogene 1 (ROS1), v-Raf murine sarcoma viral oncogene homolog B (BRAF), and rearranged during transfection (RET) genes. Although ALK, ROS1, and RET are rare genetic abnormalities, corresponding tyrosine kinase inhibitors (TKIs) can exert dramatic therapeutic effects. In addition to anticancer drugs targeting driver genes, bevacizumab specifically binds to human vascular endothelial growth factor (VEGF) and blocks the VEGF signaling pathway. The VEGF signal blockade suppresses angiogenesis in tumor tissues and inhibits tumor growth. In this review, we also explore immunotherapy, which is a promising new NSCLC treatment approach. In general, antitumor immune responses are suppressed in cancer patients, and cancer cells escape from the immune surveillance mechanism. Immune checkpoint inhibitors (ICIs) are antibodies that target the primary escape mechanisms, immune checkpoints. Patients who respond to ICIs are reported to experience longlasting therapeutic effects. A wide range of clinical approaches, including combination therapy involving chemotherapy or radiation plus adjuvant therapy, are being developed.

[Management of Drug Therapy for Leptomeningeal Metastasis of Sensitive Driver Gene Positive Non-small Cell Lung Cancer]

Leptomeningeal metastasis (LM) is one of the serious complications of advanced non-small cell lung cancer (NSCLC), although the incidence is not high, the clinical symptoms are severe and the prognosis is poor. LM is prone to occur in patients with positive driver gene than negative. At present, the treatment of LM mainly includes molecular targeted therapy, systemic chemotherapy, whole brain radiotherapy, intrathecal chemotherapy and immunotherapy. Although there are many treatments, the efficacy of LM is still unsatisfactory. This article reviews the drug therapy of sensitive driver gene positive NSCLC LM.

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.

A phase II, multicenter, two cohort study of 160 mg osimertinib in EGFR T790M-positive non-small-cell lung cancer patients with brain metastases or leptomeningeal disease who progressed on prior EGFR TKI therapy

BACKGROUND

Up to 40% of patients with non-small-cell lung cancer (NSCLC) and epidermal growth factor receptor (EGFR) mutations treated with EGFR tyrosine kinase inhibitors (TKIs) present with disease progression in the central nervous system (CNS), either as brain metastases (BM) or leptomeningeal metastases (LM). Osimertinib (80 mg), a third-generation, irreversible, oral EGFR TKI, has shown efficacy in active CNS metastases. However, efficacy of osimertinib 160 mg in BM or LM is unclear.

PATIENTS AND METHODS

This prospective, single-arm, two cohort study evaluated the efficacy of osimertinib 160 mg in T790M-positive BM or LM NSCLC patients who progressed on prior EGFR TKI (NCT03257124) treatment. The primary end points were objective response rate (ORR) (H₁ = 30%) for the BM cohort and overall survival (OS) (H₁ = 5 months) for the LM cohort.

RESULTS

The median follow-up duration was 10.1 months and 9.6 months for the BM and LM cohorts, respectively. In the BM cohort, intracranial ORR and disease control rate were 55.0% and 77.5%, respectively. The median progression-free survival (PFS) was 7.6 months [95% confidence interval (CI) 5.0-16.6]; the median OS was 16.9 months [95% CI 7.9-not reached (NR)]. In the LM cohort, intracranial disease control rate was 92.5% and complete response rate was 12.5%. The median OS was 13.3 months (95% CI 9.1-NR); the median PFS was 8.0 months (95% CI 7.2-NR). Subgroup analyses based on previous exposure to T790M-targeting agents, including osimertinib 80 mg or other third-generation EGFR TKIs, showed no difference in PFS in both the BM (n = 18, P = 0.39) and LM (n = 17, P = 0.85) cohorts. Previous radiotherapy favored PFS in the BM cohort (hazard ratio 0.42, P = 0.04). The most common adverse events were decreased appetite, diarrhea, and skin rash; however, most were grade 1-2.

CONCLUSION

Thus, osimertinib 160 mg demonstrated promising ORR and survival benefit with a tolerable safety profile in EGFR T790M-positive NSCLC patients with CNS metastasis who progressed on prior EGFR TKIs.

Safety and CSF distribution of high-dose erlotinib and gefitinib in patients of non-small cell lung cancer (NSCLC) with brain metastases

PURPOSE

Patients of non-small cell lung cancer (NSCLC) with brain metastases have limited treatment options. High-dose erlotinib (HDE) and gefitinib (HDG) have been tried in the past. This study investigates the cerebrospinal fluid (CSF) disposition and safety of both, high-dose erlotinib and gefitinib regimens.

METHODS

Eleven and nine patients were treated with erlotinib and gefitinib, respectively. All patients received 1 week of standard dose of erlotinib (150 mg OD) or gefitinib (250 mg OD), followed by the high dose (1500 mg weekly for erlotinib and 1250 mg OD for gefitinib) from day 8. Blood and CSF samples were collected on days 7 and 15, 4 h after the morning dose and drug levels determined using LC-MS/MS. Adverse events were documented as per CTCAE 4.03 till day 15.

RESULTS

Pulsatile HDE and daily HDG resulted in 1.4- and 1.9-fold increase in CSF levels, respectively. A constant 2% CSF penetration rate was observed across both doses of erlotinib, while for gefitinib the penetration rate for high dose was half that of the standard dose suggesting a nonlinear disposition. Three patients on HDE treatment discontinued treatment after the first dose due to intolerable toxicities, whereas HDG was better tolerated with no treatment discontinuations. Since CSF disposition of gefitinib followed saturable kinetics, a lower dose of 750 mg was found to achieve CSF concentrations comparable to that of the 1250 mg dose.

CONCLUSIONS

HDG was better tolerated than HDE. CSF disposition of gefitinib was found to be saturable at a higher dose. Based on these findings, the dose of 750 mg OD should be considered for further evaluation in this setting.

Nationwide Real-world Cohort Study of First-line Tyrosine Kinase Inhibitor Treatment in Epidermal Growth Factor Receptor-mutated Non-small-cell Lung Cancer

BACKGROUND

Only a few randomized trials directly compared the relative efficacy of tyrosine kinase inhibitors (TKIs) in patients with advanced epidermal growth factor receptor (EGFR)-mutated non-small-cell lung cancer (NSCLC), and most trials comprised selected series from Asian populations. Therefore, the aim of this study was to assess the overall survival (OS) of advanced EGFR-mutated NSCLC in a large white population and to evaluate variation between different TKIs and identify predictors of survival.

PATIENTS AND METHODS

Information about clinical characteristics, treatment, and survival for 873 patients with stage IV EGFR + NSCLC, diagnosed from 2015 through 2017, was derived from the Netherlands Cancer Registry. OS was evaluated by actuarial analysis and multivariable Cox regression. Prognostic factors are reported as hazard ratios and 95% confidence intervals.

RESULTS

A total of 596 (68%) patients received first-line treatment with regular TKIs, providing a median survival of 20.2 months. Forty-five percent of patients were 70 years and older, and 54% of patients had distant metastasis in multiple organs. In the multivariate analysis, survival was significantly worse for men, and patients with higher age, poorer performance, and ≥ 3 organs with metastasis. Compared with erlotinib, OS was worse for gefitinib users (adjusted hazard ratio, 1.30; 95% confidence interval, 1.02-1.64), predominantly in patients with brain metastasis.

CONCLUSION

Dutch patients with EGFR-mutated NSCLC who received first-line treatment with regular TKIs have a median OS of 20.2 months in a nationwide real-world cohort. In patients with brain metastasis, erlotinib showed superior results compared with gefitinib and was similar to afatinib.

Systemic treatment of brain metastases in non-small cell lung cancer

Brain metastases (BrMs) are associated with significant morbidity and are found in up to 50% of patients with advanced non-small cell lung cancer (NSCLC). Most of the literature focuses on symptomatic BrMs, with a lack of baseline brain imaging in asymptomatic patients. Unfortunately, much of the data on local treatments with or without systemic treatment is retrospective. Clinical trials of systemic treatments largely exclude patients with BrMs. Chemotherapy is an active treatment for BrM with response rates in the brain similar to other sites of disease. Targeted systemic treatments in patients with driver mutations (EGFR and ALK-MET to date) have impressive central nervous system (CNS) penetrance and response rates. Unfortunately, no prospective data can currently guide the timings or modality of local therapies with systemic treatments in these patients who have a high incidence of CNS disease, but retrospective data suggest that early local therapies may give better intracranial progression-free survival (ICPFS). Recent immunotherapy trials have included patients with BrMs. These patients have largely been pre-treated with local therapies and are asymptomatic. Thus, the current standard is becoming, early local therapies before or in conjunction with immunotherapy agents. The approach seems to be safe. Prospective studies are needed in NSCLC BrMs patients to make sure any benefit from local therapies on the ICPFS and quality of life is not overlooked. Here we report what we think are reasonable conclusions from the available data and make suggestions for future clinical trials in the management of NSCLC BrMs.

Strategies to prevent brain metastasis

PURPOSE OF REVIEW

The current article reviews the state of art of prevention strategies for brain metastases from solid tumors and touches both old pivotal studies and new directions of personalized molecular approaches.

RECENT FINDINGS

Prophylactic cranial irradiation (PCI) has a definite role in the prevention of relapse into the brain for patients with small cell lung cancer (SCLC) responding to chemotherapy and radiotherapy as it prolongs overall survival (OS). However, the risk of late cognitive deficit following whole brain radiotherapy (WBRT) in this patient population is still not well known. Conversely, PCI significantly reduces the incidence of brain metastases and prolongs the disease-free interval in patients with non-SCLC (NSCLC), but does not improve OS thus far. Pharmacologic prevention is a new concept driven by the efficacy of targeted agents on macrometastases from specific molecular subgroups.

SUMMARY

The future challenges for prevention of brain metastases are represented by the identification of subgroups of patients at higher risk of relapse into the brain coupled with either new WBRT strategies to better preserve cognition or effective molecular agents to target micrometastases.

Impact of Use of Gastric-Acid Suppressants and Oral Anti-Cancer Agents on Survival Outcomes: A Systematic Review and Meta-Analysis

We performed a systematic review and meta-analysis to evaluate the role of gastric acid suppressant use on outcomes of tyrosine kinase inhibitors (TKIs) and oral chemotherapy. We identified all research evaluating the effect of GAS (gastric acid suppressants) use on patients receiving oral chemotherapy or TKIs for solid tumors. The pooled hazard ratios (HRs) and 95% confidence interval (95%CI) for overall survival (OS) and progression-free survival (PFS) were calculated with a fixed-effects or a random effects model. The study population included n = 16 retrospective studies and 372,418 patients. The series concerned gastrointestinal tract tumors (n = 5 studies), renal cell carcinomas (RCC, n = 3 studies), non-small cell lung cancers (NSCLC, n = 5 studies), and soft tissue sarcomas or mixed histologies solid tumors in n = 3 studies. The pooled HRs for OS and PFS were 1.31 (95%CI: 1.20-1.43; p < 0.01) and 1.3 (95%CI 1.07-1.57; p < 0.01) for GAS and no GAS users, respectively. Only studies of EGFR (epidermal growth factor receptor) mutated NSCLC patients receiving TKIs and those with colorectal cancer receiving oral chemotherapy showed a significant correlation between GAS and poor survival. Our study supports the evidence of a possible negative impact of concomitant GAS therapy on survival outcomes of patients receiving oral anti-cancer drugs.

Management of CNS metastases in patients with EGFR mutation-positive NSCLC

Central nervous system (CNS) metastases are a frequent and severe complication associated with epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC). The first- and second-generation EGFR tyrosine kinase inhibitors (TKIs) have shown considerable efficacy in EGFR-mutated NSCLC. However, their limited potential to cross the blood-brain barrier (BBB) renders them less effective in the management of CNS metastases in NSCLC. Osimertinib, a third-generation irreversible EGFR-TKI with good potential to cross the BBB, has shown significant clinical activity and acceptable safety profile in patients with EGFR-positive NSCLC brain and leptomeningeal metastases. The progression-free survival (PFS) of up to 15.2 months in CNS metastases patients in the FLAURA trial and the CNS objective response rates (ORRs) of 54% and 43% in the AURA/AURA2 and BLOOM trials, respectively, have established the role of osimertinib in patients with NSCLC with CNS metastases. The AURA3 trial also reported a PFS of 8.5 months and overall ORR of 71%. These data have supported osimertinib to be recognized as a "preferred" first-line treatment for EGFR-positive metastatic NSCLC by the National Comprehensive Cancer Network (NCCN). With limited treatment options available, upfront administration of osimertinib in patients with NSCLC irrespective of EGFR T790M and CNS metastases may improve the overall response rate and potentially reduce the adverse effects of radiotherapy. Our review focuses on the management of EGFR-mutated NSCLC CNS metastases in the context of recent NCCN guidelines.

Management of leptomeningeal metastases in non-small cell lung cancer

In leptomeningeal metastasis (LM), malignant lung cancer cells reach the sanctuary site of the leptomeningeal space through haematogenous or lymphatic route and thrive in the leptomeninges because of restricted access of chemotherapeutic agents across the blood brain barrier. The incidence of LM is 3%-5% in non-small cell lung cancer (NSCLC) patients; the incidence is higher in patients with anaplastic lymphoma kinase (ALK) gene rearrangement or epidermal growth factor receptor (EGFR) mutations. However, the real-world burden of undiagnosed cases may be higher. LM diagnosis is based on clinical, radiological, and cytological testing. Disease management remains a challenge because of low central nervous system penetration of drugs. The prognosis of NSCLC patients with LM is poor with an overall survival (OS) of 3 months with contemporary treatment and <11 months with novel therapies. Therapy goals in this patient population are to improve or stabilize neurologic status, improve quality of life, and prolong survival while limiting the toxicity of chemotherapeutic regimens. We reviewed therapeutic options for management of LM in NSCLC patients with or without genetic mutations. Radiotherapy, systemic, or intrathecal chemotherapy, and personalized molecularly targeted therapy prolong the OS in patients with LM. Newer third generation EGFR-tyrosine kinase inhibitors have considerable brain penetration property and have been vital in increasing the OS especially in patients with EGFR mutations. Sequential or combination therapy third generation EGFR agents with radiotherapy or chemotherapy might be effective in increasing the quality of life and overall survival.

Digital PCR-Based Detection of EGFR Mutations in Paired Plasma and CSF Samples of Lung Adenocarcinoma Patients with Central Nervous System Metastases

BACKGROUND

The presence of specific mutations in the EGFR gene informs the clinical pathway of therapy for patients with lung adenocarcinoma (LAC), including those with central nervous system (CNS) metastases. Plasma circulating cell-free DNA (cfDNA) has been demonstrated to carry the mutational information of LACs, which serves as a biomarker to guide treatment. However, whether the cerebrospinal fluid (CSF) enriches circulating tumor DNA (ctDNA) released from CNS metastatic lesions of LAC, and whether the CSF ctDNA can be used to characterize these lesions remains unknown.

OBJECTIVE

To explore the EGFR status in CNS metastases of LAC patients, and to guide the treatment of intra- and extracranial tumors in these patients.

PATIENTS AND METHODS

The EGFR mutational status in the cfDNA from paired CSF and plasma samples from LAC patients with CNS metastases, including 20 brain metastases (BM) and 15 leptomeningeal metastases (LM), was assessed by droplet digital polymerase chain reaction (ddPCR). The clinical outcomes of the EGFR status-based intervention were investigated.

RESULTS

EGFR mutations were detected in 23/35 LAC patients (65.7%). EGFR mutations in the plasma or CSF were detected in 6/11 (54.5%) and 5/10 (50%) BM patients, and in 4/11 (36.4%) and 9/12(75%) LM patients, respectively. The prevalence of the T790M mutation was significantly higher in plasma (9/23) than in CSF (3/23) samples. The sensitivity and specificity of the ddPCR-based EGFR mutation test in CSF or plasma samples versus the primary tumor samples were 56% and 89% versus 46% and 100%, respectively. Twelve patients received a first-generation EGFR TKI (tyrosine kinase inhibitor) after the detection of sensitive EGFR mutations in their CSF or plasma, and five patients were switched from a first-generation EGFR TKI to osimertinib after the detection of the T790M mutation.

CONCLUSIONS

The EGFR T790M mutation in plasma cfDNA is a sensitive marker for EGFR TKI resistance when CNS metastases progressed. CSF ctDNA increases the diagnostic validity for EGFR genotyping of lung cancer brain metastasis. ddPCR in CSF and plasma samples could provide less invasive and close monitoring of the EGFR status of LAC patients with CNS metastases.

Leptomeningeal metastasis from solid tumors

Central nervous system (CNS) metastasis from systemic cancers can involve the brain parenchyma, leptomeninges (pia, subarachnoid space and arachnoid mater), and dura. Leptomeningeal metastases (LM), also known by different terms including neoplastic meningitis and carcinomatous meningitis, occur in both solid tumors and hematologic malignancies. This review will focus exclusively on LM arising from solid tumors with a goal of providing the reader an understanding of the epidemiology, pathophysiology, clinical presentation, prognostication, current management and future directions.

Dual Targeting of the Epidermal Growth Factor Receptor Using Combination of Nimotuzumab and Erlotinib in Advanced Non-Small-Cell Lung Cancer with Leptomeningeal Metastases: A Report of Three Cases

Leptomeningeal metastases (LM) occur in 3-5% of patients with advanced non-small-cell lung cancer (NSCLC) and are associated with a dismal prognosis. We report three cases of NSCLC with LM who were treated with the combination of nimotuzumab and erlotinib. Magnetic Resonance Imaging (MRI) evaluation during follow-up showed significant improvement in cancer symptoms and decreased tumor size in all three patients. Grade 3 and 4 toxicities were rarely seen. Based on apparent efficacy of the regimen and fewer side effects, we suggest that nimotuzumab in combination with erlotinib may be a promising option for the treatment of NSCLC with LM.

Osimertinib Overcomes Alectinib Resistance Caused by Amphiregulin in a Leptomeningeal Carcinomatosis Model of ALK-Rearranged Lung Cancer

INTRODUCTION

Leptomeningeal carcinomatosis (LMC) occurs frequently in anaplastic lymphoma kinase (ALK)-rearranged NSCLC and develops acquired resistance to ALK tyrosine kinase inhibitors (ALK TKIs). This study aimed to clarify the resistance mechanism to alectinib, a second-generation ALK TKI, in LMC and test a novel therapeutic strategy.

METHODS

We induced alectinib resistance in an LMC mouse model with ALK-rearranged NSCLC cell line, A925LPE3, by continuous oral alectinib treatment, established A925L/AR cells. Resistance mechanisms were analyzed using several assays, including Western blot and receptor tyrosine kinase array. We also measured amphiregulin (AREG) concentrations in cerebrospinal fluid from patients with ALK-rearranged NSCLC with alectinib-refractory LMC by enzyme-linked immunosorbent assay.

RESULTS

A925L/AR cells were moderately resistant to various ALK TKIs, such as alectinib, crizotinib, ceritinib, and lorlatinib, compared with parental cells in vitro. A925L/AR cells acquired the resistance by EGFR activation resulting from AREG overexpression caused by decreased expression of microRNA-449a. EGFR TKIs and anti-EGFR antibody resensitized A925L/AR cells to alectinib in vitro. In the LMC model with A925L/AR cells, combined treatment with alectinib and EGFR TKIs, such as erlotinib and osimertinib, successfully controlled progression of LMC. Mass spectrometry imaging showed accumulation of the EGFR TKIs in the tumor lesions. Moreover, notably higher AREG levels were detected in cerebrospinal fluid of patients with alectinib-resistant ALK-rearranged NSCLC with LMC (n = 4), compared with patients with EGFR-mutated NSCLC with EGFR TKI-resistant LMC (n = 30), or patients without LMC (n = 24).

CONCLUSIONS

These findings indicate the potential of novel therapies targeting both ALK and EGFR for the treatment of ALK TKI-resistant LMC in ALK-rearranged NSCLC.

Impact of clinicopathologic features on leptomeningeal metastasis from lung adenocarcinoma and treatment efficacy with epidermal growth factor receptor tyrosine kinase inhibitor

Background

We investigated the risk factors for leptomeningeal carcinomatosis (LMC) and compared clinical efficacies of various treatment modalities including intrathecal (IT) chemotherapy in patients with lung adenocarcinoma harboring epidermal growth factor receptor (EGFR) mutations.

Methods

Using clinical research data from the Asan Medical Center, we retrospectively analyzed data of patients diagnosed with LMC, confirmed via cerebrospinal fluid (CSF) analysis from January 2008 to December 2017.

Results

We identified 1189 patients with lung adenocarcinoma harboring EGFR mutations. Among these, 9.8% had a median duration of 13.5 (interquartile range [IQR] 6.8–23.6) months from the initial lung cancer diagnosis to LMC occurrence. Younger age (hazard ratio [HR] 1.043, P < 0.001), initial metastatic disease (HR 3.768, P < 0.001), and metastasis to the brain (HR 8.682, P < 0.001) or lung (HR 2.317, P = 0.004) were risk factors associated with LMC. Median survival duration from LMC diagnosis was 3.8 (IQR 1.5–8.6) months. Eastern Cooperative Oncology Group performance status score ≤ 2 (HR 0.505, P = 0.007) and insertion of Ommaya reservoir (HR 0.445, P = 0.005) were associated with longer survival. EGFR‐tyrosine kinase inhibitor (TKI) conferred survival benefits compared to cytotoxic chemotherapy or best supportive care (HR 2.222, P = 0.018; HR 5.638, P < 0.001, respectively). Although IT chemotherapy showed no survival benefit, it was associated with improved neurologic symptoms and signs and CSF negative conversion.

Conclusions

Younger age, initial diagnosis of metastatic disease, and metastasis to the brain or different lobes were associated with LMC in patients with EGFR‐mutant lung adenocarcinoma. Therapeutic interventions including EGFR‐TKIs, cytotoxic chemotherapy, or Ommaya reservoir, and good performance status were related to favorable survival outcomes.

Key points

Age and disease status were associated with LMC in patients with EGFR‐mutant adenocarcinoma, and EGFR‐TKI, Ommaya reservoir, and good performance status were related to survival benefit.

Osimertinib for Patients With Leptomeningeal Metastases Associated With EGFR T790M-Positive Advanced NSCLC: The AURA Leptomeningeal Metastases Analysis

INTRODUCTION

Osimertinib has shown promising activity in patients with leptomeningeal metastases (LMs) of EGFR-positive NSCLC at 160 mg once daily (qd) (BLOOM; NCT02228369). We report LM activity with osimertinib (80 mg qd) in a retrospective analysis of studies across the AURA program (AURA extension, AURA2, AURA17, and AURA3).

METHODS

Patients with EGFR T790M-positive advanced NSCLC and progression after previous EGFR-tyrosine kinase inhibitor therapy received osimertinib (80 mg qd). Patients with central nervous system (CNS) metastases (including LMs) were eligible if the lesions were neurologically asymptomatic and stable. Patients with evidence of LMs at the study entry were retrospectively included for the analysis; brain scans were assessed for radiologic LM response by neuroradiologically blinded, independent central review per the modified Response Assessment in Neuro-Oncology LM criteria. LM objective response rate, duration of response, progression-free survival, and overall survival were assessed. A longitudinal analysis was performed to investigate the relationship between changes from the baseline in non-CNS tumor sizes and LM responses at each visit of patients in AURA LM and BLOOM studies.

RESULTS

For the 22 patients included in the analysis, LM objective response rate was 55% (95% confidence interval [CI]: 32-76). Median LM duration of response was not reached (95% CI: 2.8-not calculable [NC]). Median LM progression-free survival and overall survival were 11.1 months (95% CI: 4.6-NC) and 18.8 months (95% CI: 6.3-NC), respectively. The longitudinal analysis revealed similar non-CNS and LM responses between the patients in AURA LM and BLOOM programs.

CONCLUSIONS

Patients with EGFR T790M-positive NSCLC and radiologically detected LM obtained clinical benefit from osimertinib (80 mg qd).

The optional approach of oncogene-addicted non-small cell lung cancer with brain metastases in the new generation targeted therapies era

In recent years, the study of the molecular characteristics of non-small cell lung cancer (NSCLC) has highlighted a specific role of some genes that represent important therapeutic targets, including epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK), c-ros oncogene 1 (ROS-1) and v-Raf murine sarcoma viral oncogene homolog B1 (BRAF). Patients with oncogene-addicted cancer benefit more from therapy with tyrosine kinase inhibitors (TKIs) than from chemotherapy. The brain is a preferred site for tumor spread in these patients. In addition, given greater control of extracranial disease and prolonged survival, the brain is often the first site of progression. Therefore, there is great interest in therapeutic approaches that optimize the control of intracranial disease associated with systemic drugs that, by penetrating the blood-brain barrier (BBB), may improve local control. On the latter, radiotherapy provides excellent efficacy but following the results of clinical trials with new brain penetrant drugs, the question of how and especially when to perform brain radiotherapy in patients with oncogene-addicted NSCLC remains open. Prospective studies may indicate which patients are most likely to benefit from combined use or in what sequence they will undergo systemic and radiotherapy treatment. Due to the heterogeneity of patients and the introduction of new generation TKIs, a multidisciplinary assessment for the best management of therapies in NSCLC patients with molecular driver alterations and brain metastases (BM) is required.

Brain metastases in oncogene-driven non-small cell lung cancer

Molecular targeted therapies have significantly improved the treatment outcome of patients with non-small cell lung cancer (NSCLC) harboring driver gene mutations such as receptor (EGFR) or anaplastic lymphoma kinase (ALK). However, the brain is a frequent site of recurrence, and it significantly deteriorates the prognosis of these patients. Treatment strategies include surgical resection, whole-brain radiation therapy, stereotactic radiotherapy, and drug therapy depending on patient condition. First-generation EGFR/ALK tyrosine kinase inhibitors (TKI) demonstrates only limited efficacy for intracranial lesions probably because of low penetration through the blood-brain barrier (BBB). However, newly developed TKIs with improved penetration such as osimertinib for EGFR and alectinib, ceritinib, brigatinib, or lorlatinib for ALK have demonstrated significant intracranial activity that should contribute to improved overall survival. Whole-brain radiation therapy used to be a standard of care that confers alleviation of symptom and modest survival benefit. However, it potentially causes neurological and cognitive deficits as a chronic toxicity. With the prolonged survival owing to newer generation drugs, this toxicity is becoming more relevant. Stereotactic radiotherapy is considered when there are three or fewer lesions, and the lesions are <3 cm as local control of tumor is excellent, and neurotoxicity is less. In this review, we discuss the various aspects of brain metastases occurring in NSCLC patients with driver gene mutations. We also propose a treatment algorithm for these patients.

Clinical factors associated with treatment outcomes in EGFR mutant non-small cell lung cancer patients with brain metastases: a case-control observational study

Background

Non-small cell lung cancer (NSCLC) patients harboring epidermal growth factor receptor (EGFR) mutations often develop brain metastases. Treatment with EGFR-tyrosine kinase inhibitors (TKIs) has shown the effectiveness; however, knowledge of the clinical factors associated with outcomes in NSCLC patients with EGFR mutations remains limited.

Methods

Treatment-naive patients diagnosed with advanced non-squamous NSCLC with brain metastases harboring EGFR mutations and treated with an EGFR-TKI as first-line therapy were enrolled with analysis of their medical records.

Results

A total of 134 advanced NSCLC patients with brain metastases harboring EGFR mutations received an EGFR-TKI (gefitinib: 62, erlotinib: 49, and afatinib: 23) as the first-line therapy. Sixty-nine had exon 19 deletions (51.5%), and 56 (41.8%) had L858R mutations. There was no statistically significant difference in progression-free survival (PFS) and overall survival (OS) among the EGFR-TKIs. Significantly shorter OS was noted in patients with multiple brain metastases (hazard ratio [HR]: 2.43, p = 0.007), uncommon EGFR mutations (HR: 3.75, p = 0.009), and liver metastases. Thirty-eight patients (29.1%) received brain radiotherapy for brain metastases before disease progression, and had a significantly longer time until intracranial progression. However, the brain radiotherapy had no statistically significant impact on PFS or OS.

Conclusions

Patients with uncommon mutations, multiple brain metastases, and concomitant liver metastases tended to have shorter OS. Brain radiotherapy could delay the time to intracranial disease progression but had no impact on survival. The different first-line EGFR-TKIs achieved similar treatment responses in terms of PFS and OS in the EGFR-mutated NSCLC patients with brain metastases.

An orthotopic glioblastoma animal model suitable for high-throughput screenings

Background

Glioblastoma (GBM) is an aggressive form of brain cancer with poor prognosis. Although murine animal models have given valuable insights into the GBM disease biology, they cannot be used in high-throughput screens to identify and profile novel therapies. The only vertebrate model suitable for large-scale screens, the zebrafish, has proven to faithfully recapitulate biology and pathology of human malignancies, and clinically relevant orthotopic zebrafish models have been developed. However, currently available GBM orthotopic zebrafish models do not support high-throughput drug discovery screens.

Methods

We transplanted both GBM cell lines as well as patient-derived material into zebrafish blastulas. We followed the behavior of the transplants with time-lapse microscopy and real-time in vivo light-sheet microscopy.

Results

We found that GBM material transplanted into zebrafish blastomeres robustly migrated into the developing nervous system, establishing an orthotopic intracranial tumor already 24 hours after transplantation. Detailed analysis revealed that our model faithfully recapitulates the human disease.

Conclusion

We have developed a robust, fast, and automatable transplantation assay to establish orthotopic GBM tumors in zebrafish. In contrast to currently available orthotopic zebrafish models, our approach does not require technically challenging intracranial transplantation of single embryos. Our improved zebrafish model enables transplantation of thousands of embryos per hour, thus providing an orthotopic vertebrate GBM model for direct application in drug discovery screens.

Treatment Response To Osimertinib In EGFR-Mutated Leptomeningeal Metastases From Non-Small Cell Lung Cancer: A Case Series

Therapy for leptomeningeal metastases (LM) from non-small cell lung cancer (NSCLC) is challenging, and conventional treatments have little impact on the disease course. We report three cases that were definitively diagnosed as LM from NSCLC with a mutation of epidermal growth factor receptor (EGFR) L858R. The systemic therapies of chemotherapy, local radiotherapy, and early generation tyrosine kinase inhibitors (TKIs) were implemented but ineffective. Three patients were treated with the third-generation TKI osimertinib at 80 mg daily, despite their different detection levels of T790M in the cerebrospinal fluid (CSF) and plasma, and achieved symptomatic remission, a decline of carcinoembryonic antigen (CEA) levels, and stable lesions. After the progression of LM, osimertinib at 160 mg daily further lengthened the quality of life and survival time of patients without any notable side effects during treatment. Recent related studies and our cases indicate that osimertinib has a positive effect on LM from EGFR-mutant NSCLC, regardless of T790M status.

Concurrent proton-pump inhibitors increase risk of death for lung cancer patients receiving 1st-line gefitinib treatment - a nationwide population-based study

Purpose

Concurrent proton pump inhibitor (PPI) use might reduce the plasma concentration of epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs). Clinically, the adverse effect of PPIs on patients with non-small cell lung cancer (NSCLC) treated with first-line EGFR TKIs remains controversial. This study was conducted to evaluate whether the combined use of gefitinib with PPIs affected NSCLC outcomes.

Patients and methods

We performed a nationwide cohort study of patients newly diagnosed with NSCLC between 1997 and 2013 using the Taiwan Cancer Registry and Taiwan National Health Insurance databases. We identified patients who were treated with first-line EGFR TKIs and analyzed the association between use of PPIs and TKI treatment outcome. We defined the coverage ratio of PPIs as duration of PPI treatment in days divided by duration of TKIs in days. Patients who exhibited an overlap of >20% between PPI and TKI usage days were defined as having a high coverage ratio.

Results

A total of 1278 patients were treated with first-line gefitinib, 309 of which took PPIs at the same time and 145 had a high PPI coverage ratio. Patients had similar time to failure regardless of their PPI coverage ratio during gefitinib treatment. However, higher PPI coverage ratio significantly decreased overall survival (OS) compared with that of patients with a lower PPI coverage ratio or no PPI treatment in univariate analysis (median OS, 13.5, 16.7, and 21.8 months, respectively, p<0.01) and multivariate analyses (high coverage ratio HR: 1.67; low coverage ratio HR: 1.29). Exposure to PPIs during first line gefitinib treatment significantly decreased overall survival of patients with NSCLC.

Conclusion

Concurrent use of PPIs was associated with lower overall survival in patients with EGFR-mutant NSCLC under first-line gefitinib treatment.

Whole brain radiation therapy does not improve the overall survival of EGFR-mutant NSCLC patients with leptomeningeal metastasis

Background

Leptomeningeal metastasis (LM) is a devastating and terminal complication of advanced non-small-cell lung cancer (NSCLC), especially in patients harboring epidermal growth factor receptor (EGFR) mutations. The role of whole brain radiation therapy (WBRT) in the treatment of EGFR-mutant NSCLC patients with LM is not conclusive. Therefore, we conducted a retrospective study to evaluate the therapeutic effect of WBRT in this setting.

Methods

EGFR-mutant NSCLC patients with LM, who had previously received treatment at the Shandong Cancer Hospital and Institute from July 2014 to March 2018 were reviewed retrospectively. LM was diagnosed by positive CSF cytology and/or leptomeningeal-enhanced magnetic resonance imaging (MRI). Survival was estimated using the Kaplan-Meier method.

Results

In total, 51 EGFR-mutated NSCLC patients with LM were eligible for analysis, subdivided into 26 in the WBRT group and 25 in the non-WBRT group. No significant differences were observed in intracranial ORR (15.4% vs. 16%, p = 0.952) and DCR (34.7% vs. 28%, p = 0.611) between the two groups. The median iPFS_LM and OS_LM for the entire cohort were 3.3 months (95% CI: 2.77–3.83) and 12.6 months (95% CI: 9.66–15.54), respectively. No difference in iPFS_LM was observed between the WBRT and non-WBRT groups (median 3.9 vs. 2.8 months; HR = 0.506, p = 0.052). The median OS_LM was 13.6 months in the WBRT group, compared with 5.7 months in the non-WBRT group (HR = 0.454, p = 0.022). Multivariate analyses of OS_LM showed that KPS ≥ 80 at the time of LM diagnosis (HR = 0.428, 95% CI: 0.19–0.94; p = 0.034) and the administration of EGFR-TKIs (HR = 0.258, 95% CI: 0.11–0.58; p = 0.001) were independent predictors of survival, but WBRT (HR = 0.49, 95% CI: 0.24–1.01; p = 0.54) was not. Toxicities associated with WBRT or other treatment were rare.

Conclusion

For EGFR-mutated NSCLC patients with LM, WBRT did not improve intracranial treatment response and survival statistically.

Efficacy of EGFR-TKIs with or without upfront brain radiotherapy for EGFR-mutant NSCLC patients with central nervous system metastases

Background

Although the clinical efficacy of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR‐TKIs) in EGFR‐mutant non‐small cell lung cancer (NSCLC) patients has been demonstrated, their efficacy in EGFR‐mutant NSCLCs with central nervous system (CNS) metastases and the role of radiotherapy remain unclear. This study aimed to determine if it is preferable to add upfront cranial radiotherapy to EGFR‐TKIs in patients with EGFR‐mutant NSCLC with newly diagnosed brain metastases.

Methods

We retrospectively analyzed the data of EGFR‐mutant NSCLC patients with CNS metastases who received EGFR‐TKIs as a first‐line therapy.

Results

A total of 104 patients were enrolled and 39 patients received upfront brain radiotherapy, while 65 patients received first and second generation EGFR‐TKIs first. The median time to treatment failure (TTF) was 7.8 months (95% confidence interval [CI]: 6.3–9.4). The median survival time (MST) was 24.0 months (95% CI: 20.1–30.1). The overall response rate of the CNS was 37%. The median CNS progression‐free survival (PFS) was 13.2 months (95% CI: 10.0–16.2). Brain radiotherapy prior to EGFR‐TKI prolonged TTF (11.2 vs. 6.8 months, P = 0.038) and tended to prolong CNS‐PFS (15.6 vs. 11.1 months, P = 0.096) but was not significantly associated with overall survival (MST 26.1 vs. 24.0 months, P = 0.525). Univariate and multivariate analyses indicated that poor performance status and the presence of extracranial metastases were poor prognostic factors related to overall survival.

Conclusion

EGFR‐TKI showed a favorable effect for EGFR‐mutant NSCLC patients with CNS metastases. Prolonged TTF and CNS‐PFS were observed with upfront brain radiotherapy.

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

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

Brain MRI imaging characteristics predict treatment response and outcome in patients with de novo brain metastasis of EGFR-mutated NSCLC

Patients with non-small cell lung cancer (NSCLC) and de novo brain metastasis (BM) have poor prognosis. We aim to investigate the characteristic of brain magnetic resonance (MR) imaging and the association with the treatment response of epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) for lung cancer with BM.EGFR-mutated NSCLC patients with BM from October 2013 to December 2017 in a tertiary referral center were retrospectively analyzed. Patient's age, sex, cell type, EGFR mutation status, treatment, and characteristics of BM were collected. Survival analysis was performed using Kaplan-Meier method. The efficacy of different EGFR-TKIs were also analyzed.Among the 257 eligible patients, 144 patients with Exon 19 deletion or Exon 21 L858R were included for analysis. The erlotinib group had the best progression free survival (PFS) (median PFS 13 months, P = .04). The overall survival (OS) revealed no significant difference between three EGFR-TKI groups. Brain MR imaging features including tumor necrosis, rim enhancement and specific tumor locations (frontal lobe, putamen or cerebellum) were factors associated with poor prognosis. Patients with poor prognostic imaging features, the high-risk group, who received erlotinib had the best PFS (median PFS 12 months, P < .001). However, the OS revealed no significant difference between 3 EGFR-TKI groups. The low risk group patients had similar PFS and OS treated with three different EGFR-TKIs.In NSCLC patients with common EGFR mutation and de novo BM, those with poor prognostic brain MR characteristics, erlotinib provided better PFS than afatinib or gefitinib.

Major pitfalls of protein kinase inhibitors prescription: A review of their clinical pharmacology for daily use

Protein kinase inhibitors (PKI) are a growing class of anticancer agents. They are prescribed with flat doses, and their oral administration is associated with interindividual variability in exposure. Patients can be over- or underexposed, due to numerous factors. We reviewed key pharmacokinetic concepts and mechanisms by which PKIs prescription could be altered. Challenging situations that could lead to increased toxicity or to therapeutic failure are described and recommendation for clinicians are proposed. Finally, the interest of therapeutic drug monitoring and indications for its use in daily practice is discussed.

Multidisciplinary expert opinion on the treatment consensus for patients with EGFR mutated NSCLC with brain metastases

The presence of an epidermal growth factor receptor (EGFR) mutation is associated with higher incidence of brain metastases in patients with non-small cell lung cancer (NSCLC); however, patients with synchronous brain metastases at diagnosis have generally been excluded from clinical trials. As there is limited clinical evidence for managing this patient population, a multidisciplinary group of Spanish medical and radiation oncologists, and neuro-oncologist with expertise treating brain metastases in lung cancer patients met with the aim of reaching and developing an expert opinion consensus on the management of patients with EGFR mutated NSCLC with brain metastases. This consensus contains 26 recommendations and 20 conclusion statements across 21 questions in 7 areas, as well as a first-line treatment algorithm.

Cranial Irradiation for Patients with Epidermal Growth Factor Receptor (EGFR) Mutant Lung Cancer Who Have Brain Metastases in the Era of a New Generation of EGFR Inhibitors

BACKGROUND

Immediate whole brain radiation (WBRT) has been the standard for patients with lung cancer with brain metastases. The study aims to evaluate the effect of immediate cranial irradiation in patients with epidermal growth factor receptor (EGFR) mutant lung cancer in the era of a new generation of EGFR inhibitors.

MATERIALS AND METHODS

Medical records of 198 patients with EGFR mutant non-small cell lung cancer and brain metastases at initial metastatic diagnosis were reviewed. Patients were categorized into four groups: immediate WBRT, immediate cranial stereotactic radiosurgery (SRS), delayed radiation upon progression of cranial lesions (DRT), and never cranial irradiation (NRT). Overall survival (OS) and progression-free survival related to EGFR inhibitors were analyzed.

RESULTS

The SRS group had the fewest brain metastases and fewest extracranial lesions, and the DRT and NRT groups had the smallest brain metastases. Median survival were 18.5, 55.7, 21.1, and 18.2 months for the WBRT, SRS, DRT, and NRT groups, respectively. Patients who had received EGFR T790M inhibitors survived longer (41.1 vs. 19.8 months). In multivariate analysis, the OS of patients in the SRS group was longer than that in the NRT group (adjusted hazard ratio [aHR]: 0.315). Patients who had fewer extracranial lesions and who had received EGFR T790M inhibitor treatments also survived longer (aHR: 0.442 and 0.357, respectively).

CONCLUSION

Immediate stereotactic radiosurgery but not whole brain radiation was associated with longer survival. Because of patient heterogeneity and the introduction of EGFR T790M inhibitors, the timing and modality of cranial irradiation should be determined individually, and cranial irradiation may be omitted for selected patients.

IMPLICATIONS FOR PRACTICE

Immediate whole brain radiation has been the standard for patients with lung cancer with brain metastases. In this study, it was observed that, for patients with epidermal growth factor receptor (EGFR) mutant advanced lung cancer who had brain metastases, there was no difference in survival between patients who never received cranial irradiation and those who received whole brain radiation immediately. Patients who received immediate stereotactic radiosurgery or who had ever received EGFR T790M inhibitors survived longer. Patients who received immediate stereotactic radiosurgery have fewer brain metastases. These findings suggest that the timing and modality of cranial irradiation should be determined individually, and cranial irradiation may be omitted in selected patients.

Activity of EGFR Tyrosine Kinase Inhibitors in NSCLC With Refractory Leptomeningeal Metastases

INTRODUCTION

Leptomeningeal metastases (LMs) are associated with dismal prognosis in NSCLC. Optimal management remains unknown in patients with EGFR-mutated NSCLC after initial tyrosine kinase inhibitor (TKI) failure.

METHODS

We conducted a multicenter retrospective study including patients with EGFR-mutated NSCLC and LM. TKI failure was defined as diagnosis of LM on TKI, or progression of known LM on TKI.

RESULTS

Ninety-two patients were included, median age of 60 years, predominantly female (68%), never-smokers (74%). EGFR mutations included L858R (45%), exon 19 deletions (28%), or other mutations (14%). Median time to LM diagnosis was 18.5 months after initial diagnosis of advanced NSCLC. LM was diagnosed after a median of 2 (range: 0-9) systemic therapies. Median overall survival from LM diagnosis was 6.1 months (95% confidence interval [CI]: 4.2-7.6 months). Among 87 patients with TKI failure, patients rechallenged with TKI (n = 50) had a median LM overall survival of 7.6 months (95% CI: 5.7-10.9) compared to 4.2 months (95% CI: 1.6-6.7) in patients without further therapy. Overall, 60% of patients rechallenged with TKI experienced clinical benefit (clinical response or stable disease >2 months), and 23% were treatment failure-free at 6 months. Clinical benefit was reported in 11 of 20 (55%) patients treated with erlotinib after afatinib or gefitinib. Strategies based on increasing dose intensity (n = 17) yielded clinical benefit in 59% of patients. All four patients who received osimertinib after first- and second-generation TKI experienced clinical benefit.

CONCLUSIONS

TKI rechallenge strategies, including dosing intensification, may improve clinical outcomes of patients with LM from EGFR-mutated NSCLC after initial TKI failure.

Modern Management of Central Nervous System Metastases in the Era of Targeted Therapy and Immune Oncology

Metastases to the central nervous system (CNS) are associated with considerable morbidity and mortality in patients with cancer. Historically, very few systemic therapies have shown efficacy in this patient population. Emerging data are now demonstrating that whole-brain radiation therapy, previously considered the mainstay of treatment of brain metastases, is associated with high rates of neurotoxicity. In this new era of targeted therapy and immunotherapy, clinical outcomes are improving, and patients are living longer. Despite these improvements, there is an urgent need to design central nervous system-penetrant compounds that target the genetic mutations enriched in brain metastases and to bring these to clinical trials.

Liquid biopsy in central nervous system metastases: a RANO review and proposals for clinical applications

Liquid biopsies collect and analyze tumor components in body fluids, and there is an increasing interest in the investigation of liquid biopsies as a surrogate for tumor tissue in the management of both primary and secondary brain tumors. Herein we critically review available literature on spinal fluid and plasma circulating tumor cells (CTCs) and cell-free tumor (ctDNA) for diagnosis and monitoring of leptomeningeal and parenchymal brain metastases. We discuss technical issues and propose several potential applications of liquid biopsies in different clinical settings (ie, for initial diagnosis, for assessment during treatment, and for guidance of treatment decisions). Last, ongoing clinical studies on CNS metastases that include liquid biopsies are summarized, and recommendations for future clinical studies are provided.

Standard dose osimertinib for erlotinib refractory T790M-negative EGFR-mutant non-small cell lung cancer with leptomeningeal disease

Background

Leptomeningeal spread in non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutations who experience disease progression on TKIs portends a poor prognosis. Mutation profiling of tumour DNA in cerebrospinal fluid (CSF) samples can be used to determine the presence of the EGFR T790M resistance mutation, indicating that osimertinib, a CNS-penetrating 3^rd generation TKI may be efficacious.

Methods

Eight patients on EGFR TKIs who progressed with cytology-proven leptomeningeal disease at our institution were studied. EGFR mutations were profiled in CSF using droplet digital PCR (ddPCR) and compared to matched plasma samples. Clinical characteristics and survival outcomes on subsequent therapies tailored to ddPCR analysis were reported.

Results

None of the four patients who developed leptomeningeal disease while receiving 1st generation EGFR TKIs developed the EGFR T790M mutation in CSF. One patient who did not have extra-cranial disease and was EGFR T790M-negative in both plasma and CSF was nevertheless treated with standard-dose osimertinib, and achieved a rapid and durable response lasting 9 months to date. Three patients developed leptomeningeal disease on osimertinib, with one patient developing the EGFR C797S mutation in a cis-allelic conformation with the EGFR T790M mutation in plasma.

Conclusions

Standard-dose osimertinib resulted in a clinically meaningful response in a patient with EGFR T790M-negative 1st generation EGFR TKI refractory leptomeningeal disease. Next generation sequencing and ddPCR has a role at identifying the C797S mutation and its allelic conformation with the T790M mutation with clinical implications.

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

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

Rapid effect of osimertinib re-challenge on brain metastases developing during salvage cytotoxic chemotherapy after osimertinib treatment failure: A case report

We herein report a case of symptomatic brain metastases (BM) from lung adenocarcinoma in a 73-year-old female patient, which developed during salvage cytotoxic chemotherapy following failure of osimertinib treatment. The patient was proven to have a T790M mutation prior to osimertinib therapy, and achieved a clinical benefit from osimertinib for 3 years until the primary tumor progressed. Although active BM were not detected prior to initiating salvage cytotoxic chemotherapy, the patient developed numbness of the left hand, severe dizziness, and disturbance of behavior and thought after the 3-month course of the salvage cytotoxic chemotherapy. Brain magnetic resonance imaging revealed multiple BM with severe peritumoral brain edema. To avoid radiation-induced cognitive impairment, osimertinib re-challenge was undertaken. At 2 weeks after osimertinib initiation, the patient's neurological symptoms drastically improved. One month later, radiological evaluation revealed apparent shrinkage of the BM and subsiding brain edema, although the primary lung tumor remained stable. Therefore, osimertinib re-challenge may be a viable treatment option for BM developing during salvage cytotoxic chemotherapy.

Difference in central nerve system metastasis during gefitinib or erlotinib therapy in patients with EGFR-mutated non-small cell lung cancer: a retrospective study

Background

Central nervous system (CNS) metastasis is a poor prognostic factor in patients with advanced non-small cell lung cancer (NSCLC) harboring epidermal growth factor receptor (EGFR) mutation EGFR-mutant NSCLC and is associated with a deteriorated quality of life (QOL). Some clinical studies have suggested a possible difference in the incidence of CNS metastasis between EGFR-mutant NSCLC patients treated with gefitinib and erlotinib, both of which are classified as first-generation EGFR tyrosine kinase inhibitors (TKIs). However, the difference in the incidence of CNS metastasis between patients receiving these two drugs has not yet been sufficiently well investigated. We analyzed the frequency of occurrence/progression of CNS metastasis in EGFR-mutant NSCLC patients treated with erlotinib and gefitinib as the first-line treatment.

Methods

We analyzed the incidence of CNS metastasis, frequency of progression of CNS metastasis and the treatment outcomes in EGFR-mutant patients who received gefitinib or erlotinib as the first-line EGFR-TKI treatment. CNS progressive disease (PD) was defined as progression of CNS metastasis during EGFR-TKI treatment. We also evaluated the progression-free survival (PFS), CNS-PFS, and overall survival (OS) of the patients who received each of the two drugs.

Results

A total of 170 patients were enrolled in the study, of which 144 had received gefitinib, and 26 had received erlotinib. The frequency of CNS PD in the erlotinib group tended to be lower than that in the gefitinib group (11.5% vs. 29.9%, P=0.06). In patients with no existing CNS metastasis at the start of the EGFR-TKI treatments, the incidence of CNS PD was significantly lower in the erlotinib group than that in the gefitinib group (4.8% vs. 24.5%, P=0.04). A re-biopsy after failure of EGFR-TKI treatment was performed in 48 patients. The incidence of EGFR T790M tended to be higher among patients with CNS PD than in those without CNS PD, although the difference was not statistically significant (66.7% vs. 40.4%; P=0.23).

Conclusions

The incidence of progression of CNS metastasis during erlotinib treatment was lower than that during gefitinib treatment. In addition, the difference in the incidence in patients without existing CNS metastasis at the time of start of EGFR-TKI treatment was significantly lower in the patients treated with erlotinib than in those treated with gefitinib.

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

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

Osimertinib Regresses an EGFR-Mutant Cisplatinum- Resistant Lung Adenocarcinoma Growing in the Brain in Nude Mice

The goal of the present study was to determine the efficacy of osimertinib (AZD9291), a third-generation epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor for the treatment of aggressive EGFR-mutant non-small cell lung cancer (NSCLC), compared to cisplatinum (CDDP) + pemetrexed (PEM). The NSCLC cell line PC-9 expressing green fluorescence protein (PC-9-GFP) was implanted in the brain of nude mice and was treated with CDDP + PEM or AZD9291. Tumors were observed by non-invasive fluorescence imaging. AZD9291 treatment caused tumor regression in contrast to CDDP + PEM which had only a slight inhibitory effect. These results suggest that AZD9291 is a promising clinical option for NSCLC patients with brain metastasis.

Epidermal Growth Factor Receptor Mutation Status Confers Survival Benefit in Patients with Non-Small-Cell Lung Cancer Undergoing Surgical Resection of Brain Metastases: A Retrospective Cohort Study

BACKGROUND

Few prognostic markers are available for patients with non-small-cell lung cancer (NSCLC) undergoing neurosurgical resection of symptomatic brain metastases.

OBJECTIVE

We investigated whether tumor mutation status (EGFR, KRAS, ALK, ROS1, and BRAF) and treatment history were associated with survival after neurosurgery.

METHODS

We reviewed the electronic health records of 104 patients with NSCLC with genomic profiling who underwent neurosurgical resection for symptomatic brain metastases at an academic institution between January 2000 and January 2018. We used multivariate Cox proportional hazards regression models to evaluate the association between overall survival (OS) after neurosurgery and clinicopathologic factors, including mutation status.

RESULTS

Mean age of patients in this study was 61 (±12) years, and 44% were men. The median OS after neurosurgery was 24 months (95% confidence interval, 18-34 months). Our multivariate analysis showed that the presence of an EGFR mutation in the tumor was significantly associated with improved OS (hazard ratio [HR], 0.214; P = 0.029), independent of tyrosine kinase inhibitor use. Presence of KRAS, ALK, ROS1, and BRAF alterations was not associated with survival (all P > 0.05). Conversely, older age (HR, 1.039; P = 0.029), a history of multiple brain irradiation procedures (HR, 9.197; P < 0.001), and presence of extracranial metastasis (HR, 2.556; P = 0.016) resulted in increased risk of mortality.

CONCLUSIONS

Patients requiring surgical resection of an epidermal growth factor receptor-mutated NSCLC brain metastasis had an associated improved survival compared with patients without this mutation, independent of tyrosine kinase inhibitor use. Decreased survival was associated with older age, multiple previous brain radiation therapies, and extracranial metastasis.

Prognostic impact of pleural effusion in EGFR-mutant non-small cell lung cancer patients without brain metastasis

Background

In epidermal growth factor receptor (EGFR)‐mutant non‐small cell lung cancer (NSCLC), brain metastasis is known as a poor prognosis factor. However, prognostic factors in the patients without brain metastasis remain unclear. In this study, we aimed to clarify the differences between metastatic site and prognosis in common EGFR‐mutant NSCLC patients without brain metastasis.

Methods

Chemotherapy‐naïve, advanced EGFR‐mutant NSCLC patients without brain metastasis diagnosed between January 2010 and March 2016 were enrolled. We evaluated prognosis according to the presence or absence of bone metastases, liver metastasis, and pleural effusion.

Results

A total of 50 EGFR‐mutant NSCLC patients without brain metastasis were enrolled. The median progression‐free survival and overall survival were significantly shorter in patients with pleural effusion than in those patients without (progression‐free survival 7.0 months, 95% confidence interval [CI] 3.7–13.0 vs. 13.0 months, 95% CI 9.1–21.7, hazard ratio [HR] 2.29, 95% CI 1.11–4.73, P = 0.020; overall survival 19.5 months, 95% CI 5.7–28.8 vs. 55.3 months, 95% CI 24.0–not evaluable, HR 3.00, 95% CI 1.35–6.68, P = 0.005). Pleural effusion was an independent factor of poor prognosis for progression‐free survival (HR 3.44, 95% CI 1.50–7.88, P = 0.003) and overall survival (HR 2.34, 95% CI 1.00–5.44, P = 0.049).

Conclusion

Pleural effusion might be a poor prognosis factor for advanced EGFR‐mutant NSCLC patients without brain metastasis treated with first‐generation EGFR‐tyrosine kinase inhibitors. Further precision medicine according to the metastatic site is required.

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

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

Clinical outcomes and secondary epidermal growth factor receptor (EGFR) T790M mutation among first-line gefitinib, erlotinib and afatinib-treated non-small cell lung cancer patients with activating EGFR mutations

Gefitinib, erlotinib and afatinib are approved for first-line treatment of advanced non-small cell lung cancer (NSCLC) bearing an activating epidermal growth factor receptor (EGFR) mutation. However, the clinical outcomes among the three EGFR tyrosine kinase inhibitors (TKIs) are still controversial. We aimed to evaluate clinical outcomes and secondary EGFR T790M mutation among the three EGFR TKIs. From May 2014 to January 2016, a total of 301 patients received treatment with gefitinib, erlotinib or afatinib, for first-line treatment of advanced NSCLC with an activating EGFR mutation, based on their clinicians' choice. The median overall survival (OS) was 37.0 months. Although the baseline characteristics of patients were unequal, progression-free survival and OS did not differ among the 3 groups. Multivariate analysis found that gefitinib (adjusted odds ratio [aOR] 3.29, 95% confidence interval [CI], 1.15-9.46, p = 0.027), EGFR TKI treatment duration more than 13 months (aOR 3.16, 95% CI, 1.20-8.33, p = 0.020), male (aOR 3.25, 95% CI, 1.10-9.66, p = 0.034), initial liver metastasis (aOR 4.97, 95% CI 1.18-20.96, p = 0.029) and uncommon EGFR mutation (aOR 0.14, 95% CI, 0.02-0.97, compared to EGFR deletion 19, p = 0.047) were independent factors for secondary T790M mutation. In real-world practice, choosing first line EGFR TKI based on the patients' clinical characteristics yielded good clinical outcomes. First-line gefitinib, longer EGFR TKI treatment duration, male, initial liver metastasis and uncommon EGFR mutations may be independent factors for secondary EGFR T790M mutation.

An Acquired Epidermal Growth Factor Receptor T790M Mutation after the Addition of Bevacizumab to Preceding Erlotinib Monotherapy in a Lung Cancer Patient with Leptomeningeal Metastases

A 53-year-old man with advanced lung adenocarcinoma harboring epidermal growth factor receptor (EGFR) exon 19 deletion received erlotinib. After 12 months of disease control with erlotinib monotherapy, leptomeningeal metastases (LM) occurred. A cerebrospinal fluid examination demonstrated a pre-existing EGFR exon 19 deletion. Bevacizumab was combined with erlotinib, and the LM improved. After six months of combination therapy, however, the LM was exacerbated. A re-examination of the cerebrospinal fluid revealed a T790M mutation and exon 19 deletion. Osimertinib was administered, and the LM improved. The combination of bevacizumab and erlotinib was effective for erlotinib-resistant LM and resulted in the expression of a newly acquired T790M mutation, which enabled successful treatment with osimertinib.