Leptomeningeal metastasis after effective first-generation EGFR TKI treatment of advanced non-small cell lung cancer

Effects of EGFR-TKIs combined with intracranial radiotherapy in EGFR-mutant non-small cell lung cancer patients with brain metastases: a retrospective multi-institutional analysis

BACKGROUND

Patients with non-small cell lung cancer (NSCLC) are prone to developing brain metastases (BMs), particularly those with epidermal growth factor receptor (EGFR) mutations. In clinical practice, treatment-naïve EGFR-mutant NSCLC patients with asymptomatic BMs tend to choose EGFR-tyrosine kinase inhibitors (TKIs) as first-line therapy and defer intracranial radiotherapy (RT). However, the effectiveness of upfront intracranial RT remains unclear.

METHODS

This was a retrospective study including 217 patients from two institutions between January 2018 and December 2022. Clinical data of NSCLC patients with BMs who received EGFR-TKIs were collected. The patients were assigned to one of the three groups according to the therapeutic modality used: the upfront TKI + stereotactic radiosurgery (SRS) / fractionated stereotactic radiotherapy (fSRS) group (upfront TKI + SRS/fSRS ), the upfront TKI + whole-brain radiotherapy (WBRT) group (upfront TKI + WBRT) and the upfront TKI group.

RESULTS

As of March 8, 2023, the median follow-up duration was 37.3 months (95% CI, 32.5-42.1). The median overall survival (OS) for the upfront TKI + SRS/fSRS, upfront TKI + WBRT, and upfront TKI groups were 37.8, 20.7, and 24.1 months, respectively (p = 0.015). In subgroup analysis, the upfront TKI + SRS/fSRS group demonstrated longer OS compared to the upfront TKI + WBRT and upfront TKI groups in patients treated with first or second-generation EGFR-TKIs (p = 0.021) and patients with L858R mutation (p = 0.017), whereas no survival benefit was observed in three-generation EGFR-TKIs or 19del subgroup. In the multivariable analysis, metachronous BMs, EGFR L858R mutation and nonclassic EGFR mutation were identified as independent risk factors for OS, while a DS-GPA score of 2.0-4.0 was the only independent protective factor.

CONCLUSIONS

This study demonstrated that upfront addition of SRS/fSRS to EGFR-TKIs was associated with longer OS compared to upfront WBRT or upfront TKI alone in EGFR-mutant NSCLC patients with BMs. This improvement was more significant in patients with L858R mutation and those treated with first or second-generation EGFR-TKIs. Further research with a larger sample size is warranted.

Phase II Efficacy and Safety of 80 mg Osimertinib in Patients With Leptomeningeal Metastases Associated With Epidermal Growth Factor Receptor Mutation-Positive Non-Small Cell Lung Cancer (BLOSSOM)

PURPOSE

Leptomeningeal metastases (LMs) exhibit a high incidence in patients with epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC) post-treatment with first- or second-generation EGFR tyrosine kinase inhibitors (TKIs). This investigation evaluates the efficacy, safety, and pharmacokinetics of 80 mg once daily osimertinib in patients with LMs resistant to prior first- or second-generation EGFR TKIs.

MATERIALS AND METHODS

In this phase II multicenter, open-label, single-arm study, 80 mg osimertinib was administered to patients with EGFR-mutated NSCLC who had developed LMs subsequent to treatment with prior EGFR TKIs. The primary end point was overall survival (OS), assessed alongside objective response rate by the blinded independent central review (BICR) and a pharmacokinetic analysis of plasma and cerebrospinal fluid (CSF) on the first day of cycles 3 and 6.

RESULTS

A total of 73 patients diagnosed with LM were treated with osimertinib, including 64 patients evaluable for the LM efficacy set-T790M negative (n = 62) and T790M positive (n = 2). The median OS in the full-analysis set was 15.6 months (95% CI, 11.5 to 20.2). The objective response rate for LM was 51.6%, including a 15.6% complete response, and the disease control rate was 81.3% by BICR in the LM efficacy evaluable set. The median LM progression-free survival by BICR was 11.2 months (95% CI, 7.7 to 15.3), the duration of response was 12.6 months (95% CI, 7.6 to 17.7), and OS was 15.0 months (95% CI, 11.3 to 18.7). Pharmacokinetic analysis showed that the CSF to free plasma osimertinib ratio was 22%. Most safety profiles were grade 1 and 2.

CONCLUSION

The study demonstrates significant intracranial efficacy and survival benefits of 80 mg once daily osimertinib in NSCLC patients with LMs. The data support considering daily 80 mg of osimertinib as a treatment option for EGFR-mutated NSCLC patients with LMs, irrespective of T790M mutation status.

Double-dose osimertinib combined with intrathecal injection of pemetrexed improves the efficacy of EGFR-mutant non-small cell lung cancer and leptomeningeal metastasis: case report and literature review

Leptomeningeal metastasis (LM) is a complication of non-small cell lung cancer (NSCLC) characterized by poor prognosis and short survival. A variety of therapeutic approaches have been sought to improve the efficacy of LM. Here we present a clinical case and conduct a literature review to investigate the effectiveness and safety of double-dose osimertinib combined with a pemetrexed intrathecal injection. This is an older man who underwent thoracoscopic pneumonectomy and was diagnosed with stage IIA lung adenocarcinoma with EGFR21 L858R mutation. He experienced thoracic vertebral metastases 33 months postoperatively and received first-line treatment with gefitinib combined with radiotherapy for vertebral metastases. However, the patient developed a grade 3 rash with unacceptable toxicity and his CEA levels were significantly increased 22 months later, leading to a targeted treatment adjustment to 80 mg of osimertinib orally once daily. Four months later, the patient developed LM and osimertinib dosage was increased to 160 mg once daily; however, neurological symptoms did not improve, and cerebrospinal fluid (CSF) tumor cells remained detected. Accordingly, the patient received an intrathecal injection of pemetrexed (dose 30 mg) every 2-3 months, 2-3 times per course (4-6 days each time), and continued to receive a double dose of osimertinib. After three courses of intrathecal chemotherapy, CSF tumor cells were eliminated, and neurological symptoms significantly improved. During the treatment, he experienced a one-degree rash, leukopenia, thrombocytopenia, and fatigue. This patient has been alive and well with disease control for 28 months since the diagnosis of meningeal metastases. Combining double-dose osimertinib and an intrathecal injection of pemetrexed demonstrated therapeutic efficacy and manageable adverse effects in this patient with advanced NSCLC with EGFR-mutant and LM.

Increasing discrepancy of MR imaging and CSF study in patients with leptomeningeal seeding from lung adenocarcinoma after targeted therapy using a tyrosine kinase inhibitor

PURPOSE

To evaluate the correlation between contrast-enhanced (CE) MRI and cerebrospinal fluid (CSF) cytology for the evaluation of leptomeningeal metastasis (LM) on MRI after targeted therapy with tyrosine kinase inhibitors.

METHODS

We retrospectively reviewed the data of nonsmall cell lung cancer patients registered with NCT03257124 from May 2017 to December 2018, with progressive disease despite targeted therapy. Twenty-nine patients whose MRI scans exhibited LM at the time of registration were enrolled. During the targeted therapy with osimertinib, MRI scans, and subsequent CSF examinations were performed in every 2 months. In total, 113 MRI scans and CSF cytology data after treatment were collected. For each CE MRI scan, LM positivity was evaluated on 3D T1-weighted image (T1WI) and 2D FLAIR. The correlation between MRI and CSF cytology results and the diagnostic performance of MRI with CSF cytology as a reference standard were evaluated.

RESULTS

After treatment, MRI revealed positivity for LM in 81 and negativity in 32. CSF results were positive in 69 examinations and negative in 44. The diagnostic accuracy of CE 3D T1WI and 2D FLAIR was 0.52 and 0.46, respectively. After targeted therapy, discrepancy in the CSF and MRI results tended to increase over time. The proportions of concordant MRI and CSF cytology results after targeted therapy were 66%, 58%, 62%, and 47% at the first, second, third, and fourth follow-up, respectively.

CONCLUSION

The discrepancy of MRI in evaluation of LM and CSF cytology increases over time after targeted therapy with osimertinib. LM positivity on MRI could be a surrogate imaging marker in the pre- and immediate posttargeted-treatment with Osimertinib but not after sessions of osimertinib.

Genomic analysis and clinical correlations of non-small cell lung cancer brain metastasis

Up to 50% of patients with non-small cell lung cancer (NSCLC) develop brain metastasis (BM), yet the study of BM genomics has been limited by tissue access, incomplete clinical data, and a lack of comparison with paired extracranial specimens. Here we report a cohort of 233 patients with resected and sequenced (MSK-IMPACT) NSCLC BM and comprehensive clinical data. With matched samples (47 primary tumor, 42 extracranial metastatic), we show CDKN2A/B deletions and cell cycle pathway alterations to be enriched in the BM samples. Meaningful clinico-genomic correlations are noted, namely EGFR alterations in leptomeningeal disease (LMD) and MYC amplifications in multifocal regional brain progression. Patients who developed early LMD frequently have had uncommon, multiple, and persistently detectable EGFR driver mutations. The distinct mutational patterns identified in BM specimens compared to other tissue sites suggest specific biologic underpinnings of intracranial progression.

Leptomeningeal metastasis in patients with non-small cell lung cancer after stereotactic radiosurgery for brain metastasis

OBJECTIVE

Stereotactic radiosurgery (SRS) is an effective treatment for brain metastases (BMs) in patients with non-small cell lung cancer (NSCLC). However, factors associated with the development of post-SRS leptomeningeal metastasis (LM) remain unclear. The authors analyzed the incidence and risk factors of LM development in patients with NSCLC and BMs after SRS and examined the survival outcomes and prognostic factors after LM development.

METHODS

This retrospective study included patients with NSCLC treated with SRS for MRI-diagnosed BM from 2002 to 2021. The authors recorded various clinical and demographic data, including age, sex, tumor histology, molecular profile of tumors, extracranial disease status, previous craniotomy, Karnofsky Performance Status, systemic treatments, tumor volume, and number of BMs. The management and survival outcomes after LM diagnosis were also recorded.

RESULTS

LM developed in 13.7% of patients with NSCLC and BMs after SRS treatment. Large initial tumor volume and more than 5 BM lesions, but not EGFR mutation status and post-SRS treatment, were associated with LM development after SRS. Multivariate analysis revealed that chemotherapy and targeted therapy after LM were associated with better survival in patients with LM after SRS.

CONCLUSIONS

This study is the first to evaluate the risk factors for LM in a relatively large cohort of patients with NSCLC after SRS. In patients with BMs harboring risk factors for subsequent LM, such as initial tumor volume and number of metastatic lesions, aggressive therapies with high CNS penetrating ability should be considered.

Molecular characteristics and prognostic factors of leptomeningeal metastasis in non-small cell lung cancer

BACKGROUND

Non-small cell lung cancer with leptomeningeal metastasis (NSCLC-LM) is emerging as a new management challenge for oncologists and is associated with poor prognosis. This study aimed to investigate the molecular characteristics and prognostic factors of NSCLC-LM.

METHODS

This retrospective study included 97 patients with NSCLC-LM between January 2015 and October 2021. Progression-free survival (PFS) and overall survival (OS) were evaluated. Gene mutations were detected by next-generation sequencing (NGS).

RESULTS

The median PFS and OS were 8.4 (95 % confidence interval [CI]: 4.839-11.901) and 14.0 (95 % CI: 9.254-18.746) months, respectively. Sixty-seven patients harboured epidermal growth factor receptor-mutated (EGFRm): L858R (34), 19del (29), T790M (13), and G719C with L861Q (1). Other mutations included ALK (5), ROS1 (3), KRAS (1), TP53 (14), MET amplification (6). The detection rate and types of circulating tumour DNA (ctDNA) in the cerebrospinal fluid (CSF) samples were higher than the paired plasma samples. Patients with EGFR mutations had a longer median OS than those without mutations (19.0 vs. 13.0 months, P = 0.015). Patients with gene mutations had shorter median OS than those without mutations, such as ALK (11.8 vs. 19.9 months, P = 0.014), ROS1 (12.7 vs. 19.8 months, P = 0.014), KRAS (4.0 vs. 19.0 months, P = 0.005), TP53 (15.0 vs. 19.0 months, P = 0.014), and MET amplification (6.0 vs. 19.0 months, P = 0.003). Multivariate analysis indicated that MET amplification was an independent predictor of poor survival. Along with Eastern Cooperative Oncology Group Performance Status (ECOG PS) ≥ 3, LM accompanied with brain parenchymal metastasis (BPM), extracranial disease, and seizures were independent predictors of poor survival, whereas intrathecal chemotherapy, and third-generation EGFR-TKIs were independent predictors of favorable survival.

CONCLUSIONS

CSF ctDNA detected using NGS had a high sensitivity for NSCLC-LM, showing high potential in detecting driver and drug-resistant gene mutations. Genomic profiles, combined with clinically relevant prognostic factors, will guide individualised treatments and improve the outcomes of NSCLC-LM patients.

Brain parenchymal and leptomeningeal metastasis in non-small cell lung cancer

Patients with advanced non-small cell lung cancer (NSCLC) are prone to brain metastases (BM), which essentially include brain parenchymal metastases (PM) and leptomeningeal metastases (LM). We conducted a retrospective study to comprehensively assess the clinical characteristics and risk factors of patients with advanced NSCLC who develop PM and LM. Patients with advanced NSCLC were enrolled. These patients were then divided into three groups for analysis: patients without BM (No-BM), patients with PM and patients with LM. Data on clinical characteristics of each patient at the time of diagnosis advanced NSCLC were extracted and analyzed. In addition, prediction models were developed and evaluated for PM and LM. A total of 592 patients were enrolled in the study. BM was present in 287 patients (48.5%). Among them, 185 and 102 patients had PM or LM. Patients with LM had a higher proportion of EGFR exon 21point mutations (L858R) compared to patients with No-BM and PM (p < 0.0001). The median time to the onset of PM and LM from the diagnosis of advanced NSCLC was 0 months and 8.3 months, respectively. Patients with LM had a statistically shorter over survival (OS) compared to either No-BM or PM patients (p < 0.0001). Based on independent predictive variables, two nomogram models were constructed to predict the development of PM and LM in advanced NSCLC patients, and the C-indexes were 0.656 and 0.767, respectively. Although both considered as BM, PM and LM had different clinical characteristics. And the nomogram showed good performance in predicting LM development, but not PM.

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.

Influence of the Timing of Leptomeningeal Metastasis on the Outcome of EGFR-Mutant Lung Adenocarcinoma Patients and Predictors of Detectable EGFR Mutations in Cerebrospinal Fluid

Simple Summary

Leptomeningeal metastasis (LM) is a devastating complication of lung cancer, with a generally poor outcome. We conduct the present study to evaluate the association between clinical presentations, brain images, tumor cell counts of the cerebrospinal fluid (CSF), and the epidermal growth factor receptor (EGFR) mutation detection rate in CSF among EGFR-mutant lung adenocarcinoma patients with LM and accessed the influence of the timing of LM occurrence on patient outcomes. Tumor cell numbers were semi-quantified according to tumor cells per high power field of CSF cytological slides. Radiological burden was assessed using a four-point scoring system, which evaluated LM-involved areas on brain magnetic resonance imaging. Our results suggest the association between the radiological severity score of LM, CSF tumor cell counts, and EGFR mutation detection rate in CSF. Furthermore, LM prior to first-line EGFR-tyrosine kinase inhibitor treatment was associated with an independently worse outcome.

Abstract

Background: We aim to evaluate the influence of the timing of leptomeningeal metastasis (LM) occurrence on the outcome of EGFR-mutant lung adenocarcinoma and to explore the predictors of detectable EGFR mutation in the cerebrospinal fluid (CSF). Methods: EGFR-mutant lung adenocarcinoma patients with cytologically confirmed LM were included for analysis. EGFR mutation in CSF was detected by MALDI-TOF MS plus PNA. Results: A total of 43 patients was analyzed. Of them, 8 (18.6%) were diagnosed with LM prior to first-line EGFR-TKI treatment (early onset), while 35 patients (81.4%) developed LM after first-line EGFR-TKI treatment (late onset). Multivariate analysis suggested that both late-onset LM (aHR 0.31 (95% CI 0.10–0.94), p = 0.038) and a history of third-generation EGFR-TKI treatment (aHR 0.24 (95% CI 0.09–0.67), p = 0.006) independently predicted a favorable outcome. EGFR mutation detection sensitivity in CSF was 81.4%. The radiological burden of LM significantly correlated with CSF tumor cell counts (p = 0.013) with higher CSF tumor cell counts predicting a higher detection sensitivity of EGFR mutation (p = 0.042). Conclusions: Early onset LM was an independently poor prognostic factor. A higher radiological severity score of LM could predict higher tumor cell counts in CSF, which in turn were associated with a higher detection rate of EGFR mutation.

Survival Outcomes of Patients With Epidermal Growth Factor Receptor Mutations in Non-Small Cell Lung Cancer With Leptomeningeal Metastasis

Background

Leptomeningeal metastasis (LM) is a commonly observed complication in patients with epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC). This study aimed to investigate the gene mutations, treatment strategies, and clinical outcomes in patients with LM.

Methods

We retrospectively analyzed the clinical and survival outcomes of 53 patients with EGFR-mutated NSCLC with LM.

Results

The median overall survival after LM diagnosis was 13.0 months, ranging from 0.5 to 42.0 months (95% CI = 9.067–16.933), with 64.2% maturity. Patients who received osimertinib after developing LM (n = 35) had a significantly higher rate of LM disease control (p = 0.008) and significantly longer overall survival (15.0 versus 6.0 months; hazard ratio (HR), 2.4292; 95% CI, 1.234–4.779; p = 0.045) than those who received previous generations of EGFR tyrosine kinase inhibitors (TKIs) or other localized therapies (n = 6). Logistic regression analysis showed that LM disease control status was a positive predictive factor for overall survival after developing LM (p &lt; 0.001, odds ratio = 10.797, 95% CI = 4.102–28.419).

Conclusions

Our study provides real-world clinical evidence that patients with EGFR-mutated NSCLC diagnosed with LM who developed LM had better clinical outcomes with osimertinib therapy. Our findings also suggest that LM disease control is the most effective strategy to prolong the overall survival outcomes of these patients.

Evaluation of osimertinib for advanced non-small cell lung cancer with leptomeningeal metastases: a cost-effectiveness and budget impact analysis

Background Few regimens for non-small cell lung cancer (NSCLC) with leptomeningeal metastases (LM) patients exist up to date, most with low efficacy. A retrospective analysis showed that osimertinib significantly improved the overall survival of LM patients by 11.5 months (17.0 vs. 5.5) as compared to no osimertinib treatment. Until now, no pharmacoeconomic evaluation of osimertinib has been performed to determine its feasibility for widespread use in LM patients. Aim This study analyzed the cost-effectiveness of osimertinib in LM of NSCLC from the perspective of the Chinese health care system. Methods Based on a retrospective analysis from the Samsung Medical Center, a Markov model was constructed to estimate the lifetime benefits and costs for LM patients who were treated with osimertinib. The main outcomes were cost, quality-adjusted life years (QALYs), and incremental cost-effectiveness ratio (ICER). Sensitivity analyses were performed to verify the robustness of model. A budget impact analysis was conducted to estimate the annual incremental cost of osimertinib treatment. Results Compared with patients who were not treated with osimertinib, the survival time of patients treated with osimertinib was higher by 0.69 (1.24 vs. 0.55) QALYs. The incremental cost was $11,877 ($29,232 vs. $17,355) and the ICER was $17,214/QALY, which was below the willingness-to-pay threshold of $30,867/QALY. Osimertinib treatment will increase national cancer spending by $220 million in the first year and increase to $474 million in the fifth year. Conclusions Osimertinib treatment is deemed to be cost-effective for NSCLC with LM patients, however, its use would significantly increase annual cancer spending.

Afatinib treatment in a large real-world cohort of nonsmall cell lung cancer patients with common and uncommon epidermal growth factor receptor mutation

The epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) afatinib improves survival in nonsmall cell lung cancer (NSCLC) patients with EGFR mutation. We analysed the outcome between EGFR mutation subtypes in a large afatinib-treated cohort in which 516 EGFR-mutated NSCLC patients receiving afatinib as front-line treatment. EGFR uncommon mutations include exon 20 insertion, de novo T790M of high or low allele frequency (dT790M_HAF /dT790M_LAF ), non-T790M compound mutation and others, where EGFR exon 20 insertion and dT790M_HAF were defined as type-I and the rest as type-II uncommon mutation. Four hundred and sixty-one (89.3%) and 55 (10.7%) patients were common and uncommon mutation, respectively. Exon 20 insertion and dT790M_HAF patients demonstrated a significantly shortened progression-free survival (PFS) (2.6 and 4.1 months) compared to EGFR common mutation, dT790M_LAF and other uncommon mutation patients (15.1, 27.0 and 18.4 months; P = 3 × 10^-8 ). Type-I uncommon mutation was an independent predictor of PFS (HR 4.46 [95% CI, 2.60-7.64]; P < .001) and OS (HR 2.56 [95% CI, 1.37-4.75]; P = .003). EGFR L858R patients demonstrated a significantly higher CNS progression (cause-specific HR, 3.16; 95% CI 1.24-8.08; P = .016), and type-I uncommon mutation patients exhibited a significantly higher systemic progression (cause-specific HR, 4.95; 95% CI 2.30-10.60; P = 4.3 × 10^-5 ). Tendencies of higher CNS and lower systemic progression were observed in type-II uncommon mutation patients. A PFS ≥ 12 months (OR 2.38 [95% CI, 1.18-4.89]; P = .016) and uncommon EGFR mutation (OR 0.08 [95% CI, 0.01-0.48]; P = .021) were independent predictors of secondary T790M. Afatinib-treated NSCLC patients presented an EGFR genotype-specific pattern of disease progression and outcome.

Efficacy of osimertinib for preventing leptomeningeal metastasis derived from advanced EGFR-mutated non-small cell lung cancer: a propensity-matched retrospective study

Background

Leptomeningeal metastasis (LM) is a severe complication of advanced non-small cell lung cancer (NSCLC). This retrospective study aimed to investigate the potential use of osimertinib for preventing LM in patients with advanced epidermal growth factor receptor (EGFR)-mutated NSCLC.

Methods

Patients with advanced NSCLC harboring EGFR mutations who underwent tyrosine kinase inhibitors (TKIs) therapy for at least 8 weeks between September 2016 and September 2019 were eligible for this study. All included patients were divided into two groups based on whether they received osimertinib, the osimertinib group (patients treated with osimertinib) and the control group (patients not treated with osimertinib). Propensity score matching (PSM, ratio of 1:1) was used to account for differences in baseline characteristics. The cumulative incidence of LM and the overall survival (OS) were evaluated.

Results

A total of 304 patients were included in the study population. Among them, 116 patients received osimertinib, and 188 did not. A total of 112 patients remained in each group after PSM, and the baseline characteristics were not significantly different between the two cohorts. LM developed in 11 patients (9.82%) in the osimertinib group and 24 patients (21.42%) in the control group (hazard ratio [HR] 0.38, 95% confidence interval [CI] 0.19–0.79, p = 0.009). Multivariate analysis indicated that osimertinib was an independent, statistically significant predictor for determining the risk for LM, with an HR of 0.33 (p = 0.042). At present, the OS rate data are too immature for statistical analysis.

Conclusion

Real-world data demonstrate that osimertinib can significantly reduce the incidence of LM in patients with advanced NSCLC harboring common EGFR mutations. Given this result, osimertinib should be encouraged in clinical practice for specific patient populations.

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.

Characteristics of central nervous system progression in non-small cell lung cancer treated with crizotinib or alectinib

Background

Most patients treated with anaplastic lymphoma kinase (ALK)‐tyrosine kinase inhibitors for ALK‐positive non‐small cell lung cancer (NSCLC) develop resistance, leading to metastasis, with progression to the central nervous system (CNS) being a primary concern. Although alectinib has better CNS penetration than crizotinib, patients treated with alectinib also develop CNS progression. CNS metastases more likely occurs during crizotinib treatment due to less blood‐brain barrier (BBB) penetration capability than alectinib. CNS progression pattern may be different during crizotinib and alecitinib treatment. Understanding the characteristics of CNS progression is important for developing treatment strategies.

Aims

We compared the clinical‐radiographic characteristics of CNS metastases among patients undergoing crizotinib and alectinib treatment for ALK‐positive NSCLCs.

Methods and results

We retrospectively analyzed the radiographic and clinical characteristics of CNS progression in ALK‐positive NSCLC patients treated with crizotinib or alectinib at our hospital between July 2011 and May 2020. CNS and systemic tumor progression were evaluated using computed tomography or magnetic resonance imaging. Fifty‐three and 65 patients were treated with crizotinib and alectinib, respectively. Baseline CNS metastasis was observed in 18 and 27 patients in the crizotinib and alectinib groups, respectively. Among the patients in the crizotinib and alectinib groups who developed disease progression, 15/49 (30.6%) and 9/44 (20.5%) had CNS progression, respectively (P = .344). Intra‐CNS progression‐free survival was significantly longer in the alectinib group than in the crizotinib group (median: 14.0 vs 5.6 months, P = .042). The number of CNS metastases sized ≥3 cm, rate of peritumoral brain edema, and the second progression pattern after treatment continuation was not significantly different between the groups.

Conclusion

We observed no significant difference in the clinical‐radiographic characteristics of CNS progression between patients undergoing crizotinib and alectinib treatments. Local therapy, including stereotactic radiosurgery, for CNS progression may be suitable and important following alectinib and crizotinib treatment.

Imaging Pattern of Diffuse Intrapulmonary Metastases in Lung Cancer Was Associated with Poor Prognosis to Epidermal Growth Factor Receptor Inhibitors

Background

Epidermal growth factor receptor (EGFR) mutations are more frequently seen in miliary intrapulmonary metastases than EGFR wild-type non-small cell lung cancer (NSCLC). Also, small-scale retrospective studies showed that patients harboring EGFR mutation with miliary pulmonary metastases had a worse prognosis. This study aimed to explore the impact of imaging patterns on the outcomes of EGFR tyrosine kinase inhibitor (TKI) treatment.

Methods

A cohort of treatment-naive NSCLC patients harboring EGFR mutation with intrapulmonary metastases who were prescribed with TKI were enrolled. The demographic feature, clinical outcome, and CT imaging of each patient were reviewed and analyzed.

Results

A cohort of 174 patients were enrolled. Five intrapulmonary patterns of imaging were recognized: solid nodular, ground-glass nodular, miliary, multiple uniform nodular, and not otherwise specified. Among them, miliary and multiple uniform nodular patterns had similar poor prognosis, and, therefore, were combined as diffuse group. A worse PFS (9.0 mon, 95% CI: 8.0–10.0 mon) was observed compared with the rest (non-diffuse group, 13.3 mon, 95% CI: 10.2–16.4 mon, p<0.001, HR=0.49). The objective response rates (ORR) between the two groups were 76.8% and 84.1%, respectively, with no significant difference (p = 0.474). The OS of the diffuse and the non-diffuse group were 25.6 mon (95% CI 21.9–29.3 mon) and 35.0 mon (95% CI: 27.5–42.5, p = 0.01, HR= 0.59). Organs like bone (p=0.167), liver (p=0.513), and adrenal gland (p=0.375) were involved in similar frequencies in both groups. However, brain (p=0.070) and leptomeningeal (p=0.078) metastases were less common in the non-diffuse group with marginally statistical significance. The 2 groups contained similar missense mutations, and gene amplification was more common in the non-diffuse group.

Conclusion

Patients with diffuse intrapulmonary metastases had inferior outcomes after TKI treatment. More aggressive treatments might be warranted for these patients.

[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.

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.

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).

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.