Computational markers for personalized prediction of outcomes in non-small cell lung cancer patients with brain metastases

Intracranial progression after curative treatment of early-stage non-small cell lung cancer (NSCLC) occurs from 10 to 50% and is difficult to manage, given the heterogeneity of clinical presentations and the variability of treatments available. The objective of this study was to develop a mechanistic model of intracranial progression to predict survival following a first brain metastasis (BM) event occurring at a time [Formula: see text]. Data included early-stage NSCLC patients treated with a curative intent who had a BM as the first and single relapse site (N = 31). We propose a mechanistic mathematical model able to derive computational markers from primary tumor and BM data at [Formula: see text] and estimate the amount and sizes of (visible and invisible) BMs, as well as their future behavior. These two key computational markers are [Formula: see text], the proliferation rate of a single tumor cell; and [Formula: see text], the per day, per cell, probability to metastasize. The predictive value of these individual computational biomarkers was evaluated. The model was able to correctly describe the number and size of metastases at [Formula: see text] for 20 patients. Parameters [Formula: see text] and [Formula: see text] were significantly associated with overall survival (OS) (HR 1.65 (1.07-2.53) p = 0.0029 and HR 1.95 (1.31-2.91) p = 0.0109, respectively). Adding the computational markers to the clinical ones significantly improved the predictive value of OS (c-index increased from 0.585 (95% CI 0.569-0.602) to 0.713 (95% CI 0.700-0.726), p < 0.0001). We demonstrated that our model was applicable to brain oligoprogressive patients in NSCLC and that the resulting computational markers had predictive potential. This may help lung cancer physicians to guide and personalize the management of NSCLC patients with intracranial oligoprogression.

Treatments for brain metastases from EGFR/ALK-negative/unselected NSCLC: A network meta-analysis

More clinical evidence is needed regarding the relative priority of treatments for brain metastases (BMs) from EGFR/ALK-negative/unselected non-small cell lung cancer (NSCLC). PubMed, EMBASE, Web of Science, Cochrane Library, and ClinicalTrials.gov databases were searched. Overall survival (OS), central nervous system progression-free survival (CNS-PFS), and objective response rate (ORR) were selected for Bayesian network meta-analyses. We included 25 eligible randomized control trials (RCTs) involving 3,054 patients, investigating nine kinds of treatments for newly diagnosed BMs and seven kinds of treatments for previously treated BMs. For newly diagnosed BMs, adding chemotherapy, EGFR-TKIs, and other innovative systemic agents (temozolomide, nitroglycerin, endostar, enzastaurin, and veliparib) to radiotherapy did not significantly prolong OS than radiotherapy alone; whereas radiotherapy + nitroglycerin showed significantly better CNS-PFS and ORR. Surgery could significantly prolong OS (hazard ratios [HR]: 0.52, 95% credible intervals: 0.41-0.67) and CNS-PFS (HR: 0.32, 95% confidence interval: 0.18-0.59) compared with radiotherapy alone. For previously treated BMs, pembrolizumab + chemotherapy, nivolumab + ipilimumab, and cemiplimab significantly prolonged OS than chemotherapy alone. Pembrolizumab + chemotherapy also showed better CNS-PFS and ORR than chemotherapy. In summary, immune checkpoint inhibitor (ICI)-based therapies, especially ICI-combined therapies, showed promising efficacies for previously treated BMs from EGFR/ALK-negative/unselected NSCLC. The value of surgery should also be emphasized. The result should be further confirmed by RCTs.

The role of immune checkpoint inhibitors in patients with intracranial metastatic disease

Intracranial metastatic disease (IMD) complicates the course of nearly 2-4% of patients with systemic cancer. The prevalence of IMD has been increasing over the past few decades. Historically, definitive treatment for brain metastases (BM) has been limited to radiation therapy or surgical resection. Chemotherapies have not typically proven valuable in the treatment of IMD, with the exception of highly chemotherapy-sensitive lesions. Recent data have supported a role for systemic targeted therapies and immune checkpoint inhibitors (ICIs) in the treatment of select patients with IMD. There remains, however, a clear clinical need for further investigation to delineate the role of ICIs in patients with BM. In this review, we outline and describe recent and current efforts to identify the efficacy of ICI therapy in patients with IMD.

Genomic and immunogenomic analysis of three prognostic signature genes in LUAD

BACKGROUND

Searching for immunotherapy-related markers is an important research content to screen for target populations suitable for immunotherapy. Prognosis-related genes in early stage lung cancer may also affect the tumor immune microenvironment, which in turn affects immunotherapy.

RESULTS

We analyzed the differential genes affecting lung cancer patients receiving immunotherapy through the Cancer Treatment Response gene signature DataBase (CTR-DB), and set a threshold to obtain a total of 176 differential genes between response and non-response to immunotherapy. Functional enrichment analysis found that these differential genes were mainly involved in immune regulation-related pathways. The early-stage lung adenocarcinoma (LUAD) prognostic model was constructed through the cancer genome atlas (TCGA) database, and three target genes (MMP12, NFE2, HOXC8) were screened to calculate the risk score of early-stage LUAD. The receiver operating characteristic (ROC) curve indicated that the model had good prognostic value, and the validation set (GSE50081, GSE11969 and GSE42127) from the gene expression omnibus (GEO) analysis indicated that the model had good stability, and the risk score was correlated with immune infiltrations to varying degrees. Multi-type survival analysis and immune infiltration analysis revealed that the transcriptome, methylation and the copy number variation (CNV) levels of the three genes were correlated with patient prognosis and some tumor microenvironment (TME) components. Drug sensitivity analysis found that the three genes may affect some anti-tumor drugs. The mRNA expression of immune checkpoint-related genes showed significant differences between the high and low group of the three genes, and there may be a mutual regulatory network between immune checkpoint-related genes and target genes. Tumor immune dysfunction and exclusion (TIDE) analysis found that three genes were associated with immunotherapy response and maybe the potential predictors to immunotherapy, consistent with the CTR-DB database analysis.

CONCLUSIONS

From the perspective of data mining, this study suggests that MMP12, NFE2, and HOXC8 may be involved in tumor immune regulation and affect immunotherapy. They are expected to become markers of immunotherapy and are worthy of further experimental research.

Efficacy of immune checkpoint inhibitor therapy in EGFR mutation-positive patients with NSCLC and brain metastases who have failed EGFR-TKI therapy

Background

Few treatment options are available for brain metastases (BMs) in EGFR-mutant non-small cell lung cancer (NSCLC) that progress with prior EGFR tyrosine kinase inhibitor (EGFR-TKI) therapy. This study aimed to evaluate the efficacy of immune checkpoint inhibitor (ICI) therapy in these patients.

Methods

NSCLC patients with confirmed sensitive EGFR mutations and BMs were retrospectively reviewed. All patients experienced failure of EGFR-TKI therapy and were divided into two cohorts based on subsequent treatment. Cohort 1 included patients who received ICI therapy, while cohort 2 included patients treated with chemotherapy. Overall and intracranial objective response rates (ORRs) were used to evaluate the treatment response. Overall and intacranial progression-free survival (PFS) were calculated by Kaplan−Meier analysis and compared with the log-rank test. Univariate and multivariate Cox analyses were used to identify prognostic factors.

Results

A total of 53 patients treated with ICI therapy and 40 patients treated with chemotherapy were included in cohorts 1 and 2, respectively. In cohort 1, the overall ORR was 20.8%, with a median overall PFS of 4.2 months. The median intracranial PFS was 5.1 months. Of the 38 patients with measurable intracranial lesions, the intracranial ORR was 21.0%. Patients who received ICI combined with chemotherapy had the highest intracranial ORR of 37.5%. Compared to patients treated with chemotherapy in cohort 2, patients receiving ICI combined with chemotherapy had both longer intracranial PFS (6.4 vs. 5.1 months, p = 0.110) and overall PFS (6.2 vs. 4.6 months, p = 0.054), and these differences approached statistical significance. Univariate and multivariate Cox analyses demonstrated that high disease burden (p = 0.019), prior third-generation EGFR-TKI therapy (p = 0.019), and a poor lung immune prognostic index (LIPI) (p = 0.012) were independent negative predicators of overall PFS and that multiple BMs were negatively correlated with intracranial PFS among patients treated with ICI therapy.

Conclusions

Our results suggested that ICI combined with chemotherapy had potent intracranial efficacy and may be a promising treatment candidate in EGFR-mutant NSCLC patients with BMs for whom prior EGFR-TKI therapy failed.

Reshaping the systemic tumor immune environment (STIE) and tumor immune microenvironment (TIME) to enhance immunotherapy efficacy in solid tumors

The development of combination immunotherapy based on the mediation of regulatory mechanisms of the tumor immune microenvironment (TIME) is promising. However, a deep understanding of tumor immunology must involve the systemic tumor immune environment (STIE) which was merely illustrated previously. Here, we aim to review recent advances in single-cell transcriptomics and spatial transcriptomics for the studies of STIE, TIME, and their interactions, which may reveal heterogeneity in immunotherapy responses as well as the dynamic changes essential for the treatment effect. We review the evidence from preclinical and clinical studies related to TIME, STIE, and their significance on overall survival, through different immunomodulatory pathways, such as metabolic and neuro-immunological pathways. We also evaluate the significance of the STIE, TIME, and their interactions as well as changes after local radiotherapy and systemic immunotherapy or combined immunotherapy. We focus our review on the evidence of lung cancer, hepatocellular carcinoma, and nasopharyngeal carcinoma, aiming to reshape STIE and TIME to enhance immunotherapy efficacy.

The Strategies and Mechanisms of Immune Checkpoint Inhibitors for Brain Metastases in NSCLC

Brain metastases are more and more common among patients with non-small cell lung cancer (NSCLC). TKI therapy could provide ideal outcomes for patients harboring epidermal growth factor receptor or ALK mutations. For wild-type patients, however, survival is poor because there are few effective treatments other than radiotherapy. Immune checkpoint inhibitors (ICIs) have changed the management of advanced NSCLC. However, the exclusion of patients with active brain metastasis (BM) from most ICI trials precludes the generalization of results. Accordingly, a variety of appropriate real-world studies and clinical trials are being developed to evaluate tumor response. Increasingly encouraging results have suggested that ICIs could be active in the central nervous system (CNS) in select patients with high PD-L1 expression and low CNS disease burden. With the extensive use of ICIs in NSCLC patients with BM, many important questions have emerged concerning issues such as the clinical response to a single ICI, use of ICIs combined with chemotherapy or radiation, the biological mechanism and appropriate sequencing of local and systemic therapy combinations, and safety and toxicity. The present review summarizes the advances in systemic ICIs for the treatment of NSCLC patients with BM, discusses factors associated with efficacy and toxicity, and explores future directions.

The Long-Term and Short-Term Efficacy of Immunotherapy in Non-Small Cell Lung Cancer Patients With Brain Metastases: A Systematic Review and Meta-Analysis

Background

Although immunotherapy has been widely used, there is currently no research comparing immunotherapy for non-small cell lung cancer (NSCLC) patients with brain metastases (BMs). This meta-analysis addresses a gap in the comparison of immunotherapy efficacy, including immune checkpoint inhibitors (ICIs), chemotherapy (CT), radiotherapy (RT), and ICI combined CT or RT.

Methods

A search of Pubmed, Cochrane, EMBASE, and ClinicalTrial.gov was conducted to identify studies which enrolled NSCLC patients with BM treated with ICIs. The outcomes consisted of intracerebral overall response rate (iORR), intracerebral disease control rate (iDCR), extracranial overall response rate (EORR), distant brain failure (DBF), local control (LC), progression-free survival (PFS), and overall survival (OS).

Results

A total of 3160 participants from 46 trials were included in the final analysis. Patients treated with immunotherapy were associated with a longer PFS (0.48, 95%CI: 0.41-0.56), and a longer OS (0.64, 95%CI: 0.60-0.69) compared with immunotherapy-naive patients. In prospective studies, dual ICI combined CT and ICI combined CT achieved a better OS. The hazard ratio (HR) of dual ICI combined CT versus dual ICI was 0.61, and the HR of ICI combined CT versus ICI monotherapy was 0.58. Moreover, no statistical difference in PFS, OS, EORR, iORR, iDCR, and EDCR was found between patients with ICI monotherapy and ICI combined cranial radiotherapy. Concurrent ICI combined RT was shown to decrease the rate of DBF (OR = 0.15, 95% CI: 0.03-0.73) compared with RT after ICI. Patients treated with WBRT might have an inferior efficacy than those with SRS because the iORR of SRS was 0.75 (0.70, 0.80) and WBRT was 0. Furthermore, no obvious difference in PFS and OS was observed among the three different types of ICI, which targets PD-1, PD-L1, and CTLA-4, respectively.

Conclusions

Patients treated with ICI got superior efficacy to those without ICI. Furthermore, dual ICI combined CT and ICI combined CT seemed to be optimal for NSCLC patients with BM. In terms of response and survival, concurrent administration of SRS and ICI led to better outcomes for patients with BMs than non-concurrent or non-SRS.

Importance of the Study

In the new era of immunotherapy, our meta-analysis validated the importance of immunotherapy for non-small cell lung cancer (NSCLC) patients with brain metastases (BMs). By comparing the long-term and short-term impacts of various regimens, all immunotherapy treatments had superior efficacy to immunotherapy-naive. At the same time, through pairwise comparison in immunotherapy, our findings can help clinicians to make treatment decisions for NSCLC patients with BMs.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=269621, identifier CRD42021269621.

Efficacy of PD-1/PD-L1 inhibitors in patients with non-small cell lung cancer and brain metastases: A real-world retrospective study in China

BACKGROUND

There is only limited knowledge of the treatment responses and clinical outcomes of immune checkpoint inhibitors (ICIs) in driver gene-negative non-small cell lung cancer (NSCLC) patients with brain metastases (BM). This study aims to assess the efficacy of immunotherapy in these patients in a real world setting.

METHODS

NSCLC-BM patients without driver gene mutations who received ICIs were retrospectively identified between July 2017 and December 2019. The primary observation endpoint was intracranial objective response rate (iORR), and secondary objectives were objective response rate (ORR), intracranial and systemic progression-free survival (iPFS, PFS), and overall survival (OS).

RESULTS

We reviewed 1578 patients with lung cancer and BM. According to the exclusion criteria, 41 patients were finally enrolled. Among these 41 patients, iORR was 36.6% (95% confidence interval [CI] = 21.2%-52.0%), whereas iPFS was 6.8 (95% CI = 3.32-10.35) months. Additionally, ORR, PFS, and OS were 24.4% (95% CI = 10.7%-38.1%), 6.2 (95% CI = 4.57-7.83) months and 13.7 (95% CI = 11.20-16.26) months, respectively. ICIs combined with concurrent radiotherapy group exhibited preferred iORR (p = 0.030) compared with no radiotherapy group, and ICIs plus chemotherapy showed improved OS (p = 0.024) compared to ICI monotherapy. Moreover, the lines of ICI treatment ≥2 (p = 0.005) and derived neutrophil-to-lymphocyte ratio (dNLR) ≥3 (p = 0.010) were independently negative factors for OS.

CONCLUSION

In NSCLC-BMs patients lacking driver genes, ICIs exhibited an effective drug regime. A combination of ICIs with concurrent radiotherapy showed a better intracranial response, whereas ICIs plus chemotherapy were associated with superior OS.

Outcomes With Pembrolizumab Monotherapy in Patients With Programmed Death-Ligand 1-Positive NSCLC With Brain Metastases: Pooled Analysis of KEYNOTE-001, 010, 024, and 042

Introduction

We retrospectively evaluated outcomes in patients with programmed death-ligand 1 (PD-L1)–positive non–small-cell lung cancer (NSCLC) to determine whether baseline (i.e., at study enrollment) brain metastases were associated with the efficacy of pembrolizumab versus chemotherapy.

Methods

We pooled data for patients with previously treated or untreated PD-L1‒positive (tumor proportion score [TPS], ≥1%) advanced or metastatic NSCLC in KEYNOTE-001 (NCT01295827), KEYNOTE-010 (NCT01905657), KEYNOTE-024 (NCT02142738), and KEYNOTE-042 (NCT02220894). Patients received pembrolizumab (2 mg/kg, 10 mg/kg, or 200 mg every 3 wk or 10 mg/kg every 2 wk); chemotherapy was a comparator in all studies except KEYNOTE-001. All studies included patients with previously treated, stable brain metastases.

Results

A total of 3170 patients were included, 293 (9.2%) with and 2877 (90.8%) without baseline brain metastases; median (range) follow-up at data cutoff was 12.9 (0.1‒43.7) months. Pembrolizumab improved overall survival versus chemotherapy in patients with or without baseline brain metastases: benefit was seen in patients with PD-L1 TPS ≥50% (0.67 [95% confidence intervals (CI): 0.44‒1.02] and 0.66 [95% CI: 0.58‒0.76], respectively) and PD-L1 TPS ≥1% (0.83 [95% CI: 0.62‒1.10] and 0.78 [95% CI: 0.71‒0.85], respectively). Progression-free survival was improved, objective response rates were higher, and duration of response was longer with pembrolizumab versus chemotherapy regardless of brain metastasis status. The incidence of treatment-related adverse events with pembrolizumab versus chemotherapy was 66.3% versus 84.4% in patients with brain metastases and 67.2% versus 88.3% in those without.

Conclusions

Pembrolizumab monotherapy improved outcomes and was associated with fewer adverse events than chemotherapy in patients with treatment-naive and previously treated PD-L1‒positive advanced/metastatic NSCLC regardless of the presence of baseline treated, stable brain metastases.

Immunotherapy in Non-Small Cell Lung Cancer Patients with Brain Metastases: Clinical Challenges and Future Directions

Immune checkpoint inhibitors have revolutionized the treatment landscape for patients with non-small cell lung cancers. Existing treatment paradigms for brain metastases in lung cancer patients leave patients with adverse neurocognitive function, poor quality of life, and dismal prognosis, thus highlighting the need to develop more effective systemic therapies. Although data are limited, emerging knowledge suggests promising activity and safety of immune checkpoint inhibitors in brain metastases in non-small cell lung cancer patients. This review aims to summarize the current data, highlight the challenges of incorporating immune checkpoint inhibitors in treating these patients, and identify areas for future research.

Immune checkpoint inhibitors for brain metastases in non-small-cell lung cancer: from rationale to clinical application

Brain metastases (BM) is common in non-small-cell lung cancer (NSCLC) patients. Immune checkpoint inhibitors (ICIs) have gradually become a routine treatment for NSCLC BM patients. Currently, three PD-1 inhibitors (pembrolizumab, nivolumab and cemiplimab), one PD-L1 inhibitor (atezolizumab) and one CTLA-4 inhibitor (ipilimumab) have been approved for the first-line treatment of metastatic NSCLC. It is still controversial whether PD-L1, tumor infiltrating lymphocytes, and tumor mutation burden can be used as predictive biomarkers for immune checkpoint inhibitors in NSCLC patients with BM. In addition, clinical data on NSCLC BM were inadequate. Here, we review the theoretical basis and clinical data for the application of ICIs in the therapy of NSCLC BM.

Multidisciplinary Management of Brain Metastases from Non-Small Cell Lung Cancer in the Era of Immunotherapy

OPINION STATEMENT

Brain metastases from non-small cell lung cancer often cause neurologic symptoms which lead to initial diagnosis or identification of recurrence. In other patients, they are identified on surveillance imaging or when a patient undergoing treatment develops neurological symptoms. Patients with symptomatic lesions should be started on dexamethasone and evaluated by a neurosurgeon as soon as possible. If feasible, surgery should be offered to decrease intracranial pressure, alleviate symptoms, and prevent irreversible neurological damage. Postoperative stereotactic radiosurgery (SRS) to the resection cavity and any additional brain metastases should follow within 4 weeks of surgery, as early as 2 weeks post-op. Tissue from surgery is used to confirm the diagnosis and test for targetable oncogenic driver mutations. Treatment response and surveillance for development of additional lesions is assessed with MRI of the brain 1 month after SRS and every 3 months thereafter. Patients who are not surgical candidates or who have small, asymptomatic brain metastases should proceed with SRS, the preferred treatment, or sometimes whole-brain radiation therapy (WBRT) if multifocal disease requires more extensive treatment, such as for leptomeningeal spread of disease. The number of brain metastases that warrants use of WBRT over SRS is controversial and a topic of ongoing investigation, and is discussed in this review. When possible, SRS is preferred over WBRT due to reduce morbidity and cognitive side effects. When patients are already on systemic therapy at time of brain metastases diagnosis, systemic therapy should continue, with radiation therapy occurring between cycles. Regarding systemic therapy for new diagnosis at time of brain metastases presentation, molecular testing will guide treatment choice, when available. If there is no neurosurgical intervention, biopsy of another site of disease may provide tissue for molecular testing. If there are no targetable oncogenic driver mutations, concurrent immune checkpoint blockade (ICB) and chemotherapy is preferable for patients who can tolerate it. Single-agent ICB is an alternative option for patients who cannot tolerate chemotherapy. Systemic therapy should start as soon as possible. In some patients with poor performance status, best supportive care may be the most appropriate choice. Treatment decisions should always incorporate patients' goals of care and in many cases should be discussed in a multidisciplinary setting.

The Effect of Asymptomatic and/or Treated Brain Metastases on Efficacy of Immune Checkpoint Inhibitors in Metastatic Non-Small Cell Lung Cancer: A Meta-Analysis

BACKGROUND

To assess the effect of asymptomatic and/or treated brain metastases (BMs) on the efficacy of immune checkpoint inhibitors (ICIs) in metastatic non-small cell lung cancer (NSCLC).

PATIENTS AND METHODS

PubMed, Embase, Cochrane Library, Web of Science, and recent meetings were searched for randomized controlled trials (RCTs). The primary outcomes of interest were overall survival (OS) and progression-free survival (PFS).

RESULTS

Seventeen articles reporting 15 RCTs with 10,358 patients (1,199 with and 9,159 without BMs) were eligible. ICIs were associated with longer OS and PFS than those in chemotherapy either in patients with (hazard ratio [HR], 0.65; 95% confidence interval [CI], 0.51-0.82 and HR, 0.60; 95% CI, 0.45-0.79) or without BMs (HR, 0.74; 95% CI, 0.70-0.78 and HR, 0.70; 95% CI, 0.57-0.86); no significant difference in the pooled HRs for OS (Pinteraction = 0.29) and PFS (Pinteraction = 0.37) was observed between the two patient populations. Subgroup analyses revealed that either ICI monotherapy or combination therapy significantly improved OS and PFS compared with those in chemotherapy both for patients with and without BMs. Superior OS benefit from ICI combination therapy than that in monotherapy was observed in patients with BMs (HR, 0.49 vs. 0.81, Pinteraction = 0.005) but not in patients without BMs (HR, 0.71 vs. 0.76, Pinteraction = 0.27).

CONCLUSION

There was no compelling statistical evidence that the efficacy of ICIs in metastatic NSCLC was modified by the presence of asymptomatic and/or treated BMs. Patients with BMs were likely to obtain more OS benefit from ICI combination therapy than that from monotherapy.

Emerging principles of brain immunology and immune checkpoint blockade in brain metastases

Brain metastases are the most common type of brain tumours, harbouring an immune microenvironment that can in principle be targeted via immunotherapy. Elucidating some of the immunological intricacies of brain metastases has opened a therapeutic window to explore the potential of immune checkpoint inhibitors in this globally lethal disease. Multiple lines of evidence suggest that tumour cells hijack the immune regulatory mechanisms in the brain for the benefit of their own survival and progression. Nonetheless, the role of the immune checkpoint in the complex interplays between cancers cells and T cells and in conferring resistance to therapy remains under investigation. Meanwhile, early phase trials with immune checkpoint inhibitors have reported clinical benefit in patients with brain metastases from melanoma and non-small cell lung cancer. In this review, we explore the workings of the immune system in the brain, the immunology of brain metastases, and the current status of immune checkpoint inhibitors in the treatment of brain metastases.

Anti-PD-(L)1 immunotherapy for brain metastases in non-small cell lung cancer: Mechanisms, advances, and challenges

The brain is one of the most common metastatic sites in non-small cell lung cancer (NSCLC), which is associated with an extremely poor prognosis. Despite the availability of several therapeutic options, the treatment efficacy remains unsatisfactory for NSCLC brain metastases. Anti-programmed cell death-1 (PD-1) and its ligand (PD-L1) monoclonal antibodies have reshaped therapeutic strategies in advanced NSCLC. Preliminary evidence has shown that anti-PD-(L)1 monotherapy is also effective in NSCLC patients with brain metastases. However, the traditional view asserted that these therapeutic antibodies were incapable of crossing the blood-brain barrier (BBB) with large molecular size, thus most patients with brain metastases were excluded from most studies on anti-PD-(L)1 immunotherapy. Therefore, the efficacy and its mechanisms of action of anti-PD-(L)1 immunotherapy against brain metastases in NSCLC have not been clarified. In this review, we will survey the underlying mechanisms and current clinical advances of anti-PD-(L)1 immunotherapy in the treatment of brain metastases in NSCLC. The trafficking of activated cytotoxic T cells that are mainly derived from the primary tumor and deep cervical lymph nodes is critical for the intracranial response to anti-PD-(L)1 immunotherapy, which is driven by interferon-γ (IFN-γ). Additionally, promising combined strategies with the rationale in the treatment of brain metastases will be presented to provide future directions for clinical study design. Several significant challenges in the preclinical and clinical studies of brain metastases, as well as potential solutions, will also be discussed.

Management of brain metastases from lung cancer in the era of immunotherapy: a review of the literature

The brain is one of the most frequent sites of metastases in lung cancer patients, whose prognosis is related to the histological, biomolecular and clinical features of the disease. Over the years, the survival has improved significantly with the introduction of immune checkpoint inhibitors (ICIs), but there are limited data concerning their efficacy in patients with brain metastases. The aim of this review is to describe the biological mechanisms supporting the use of immunotherapy for brain metastases and the outcomes experienced by lung cancer patients with brain involvement enrolled in Phase III registration trials of ICIs. We also review retrospective data on ICIs alone or combined with brain radiotherapy, and indicate future directions for preclinical and clinical research.

Tyrosine Kinase Inhibitors as a Treatment of Symptomatic CNS Metastases in Oncogene-Driven NSCLC

Central nervous system (CNS) metastases occur frequently in oncogene-driven non-small cell lung cancer (NSCLC). Standard treatment approaches can potentially delay systemic treatment (surgical intervention) or result in neurocognitive impairment (radiotherapy). Recently, next-generation tyrosine kinase inhibitors (TKIs) have demonstrated remarkable intracranial activity. However, most clinical trials did not enroll patients suffering neurological symptoms. Our study aimed to assess the CNS activity of targeted therapies in this patient population. We present a case series of nine NSCLC patients with either EGFR mutation or ALK rearrangement and symptomatic CNS metastases that were treated with TKIs. Clinicopathological characteristics, treatment, and outcomes were analyzed. Most patients presented with symptomatic CNS metastases at time of metastatic disease presentation (6/9). Additionally, the majority of patients had leptomeningeal disease (6/9) and multiple parenchymal metastases. Patients presented with a variety of CNS symptoms with the most common being nausea, vomiting, headache, and confusion. Most patients (6/9) responded rapidly both clinically and radiographically to the targeted treatment, with a marked correlation between systemic and intracranial radiographic response. In conclusion, upfront use of next-generation TKIs in patients with oncogene-driven NSCLC with symptomatic CNS metastases is associated with reasonable intracranial activity and represents a valuable treatment option.

Immunotherapy in NSCLC patients with brain metastases. Understanding brain tumor microenvironment and dissecting outcomes from immune checkpoint blockade in the clinic

BACKGROUND

Brain metastases are frequent complications in patients with non-small-cell lung cancer (NSCLC) associated with significant morbidity and poor prognosis. Our goal is to give a global overlook on clinical efficacy from immune checkpoint inhibitors in this setting and to review the role of biomarkers and molecular interactions in brain metastases from patients with NSCLC.

METHODS

We reviewed clinical trials reporting clinical outcomes of patients with NSCLC with brain metastases as well as publications assessing the tumor microenvironment and the complex molecular interactions of tumor cells with immune and resident cells in brain metastases from NSCLC biopsies or preclinical models.

RESULTS

Although limited data are available on immunotherapy in patients with brain metastases, immune checkpoint inhibitors alone or in combination with chemotherapy have shown promising intracranial efficacy and safety results. The underlying mechanism of action of immune checkpoint inhibitors in the brain niche and their influence on tumor microenvironment are still not known. Lower PD-L1 expression and less T CD8⁺ infiltration were found in brain metastases compared with matched NSCLC primary tumors, suggesting an immunosuppressive microenvironment in the brain. Reactive astrocytes and tumor associated macrophages are paramount in NSCLC brain metastases and play a role in promoting tumor progression and immune evasion.

CONCLUSIONS

Discordances in the immune profile between primary tumours and brain metastases underscore differences in the tumour microenvironment and immune system interactions within the lung and brain niche. The characterization of immune phenotype of brain metastases and dissecting the interplay among immune cells and resident stromal cells along with cancer cells is crucial to unravel effective immunotherapeutic approaches in patients with NSCLC and brain metastases.

Combination treatments with immunotherapy in brain metastases patients

Immune checkpoint inhibitors (ICI) have revolutionized the treatment of many advanced cancers. However, in most pivotal trials, patients with brain metastases (BM) were either excluded, or only selected patients were allowed. Therefore, there are still some concerns about the safety/efficacy ratio of ICI in patients with BM. In this special report we will provide an overview on the biological rationale for using ICI in the treatment of BM, the reported BM-related outcomes of clinical trials with a focus on ICI plus chemotherapy and ICI plus ICI combinations. Last, we will provide future challenges with this strategy, as well as directions for future research.

EPSILoN: A Prognostic Score for Immunotherapy in Advanced Non-Small-Cell Lung Cancer: A Validation Cohort

BACKGROUND

Beyond programmed death ligand 1 (PD-L1), no other biomarkers for immunotherapy are used in daily practice. We previously created EPSILoN (Eastern Cooperative Oncology Group performance status (ECOG PS), smoking, liver metastases, lactate dehydrogenase (LDH), neutrophil-to-lymphocyte ratio (NLR)) score, a clinical/biochemical prognostic score, in 154 patients treated with second/further-line immunotherapy. This study's aim was to validate EPSILoN score in a different population group.

METHODS

193 patients were included at National Cancer Institute of Milan (second-line immunotherapy, 61%; further-line immunotherapy, 39%). Clinical/laboratory parameters such as neutrophil-to-lymphocyte ratio and lactate dehydrogenase levels were collected. Kaplan-Meier and Cox hazard methods were used for survival analysis.

RESULTS

Overall median progression-free survival and median overall survival were 2.3 and 7.6 months, respectively. Multivariate analyses for Progression-Free Survival (PFS) identified heavy smokers (hazard ratio (HR) 0.71, p = 0.036) and baseline LDH < 400 mg/dL (HR 0.66, p = 0.026) as independent positive factors and liver metastases (HR 1.48, p = 0.04) and NLR ≥ 4 (HR 1.49, p = 0.029) as negative prognostic factors. These five factors were included in the EPSILoN score which was able to stratify patients in three different prognostic groups, high, intermediate and low, with PFS of 6.0, 3.8 and 1.9 months, respectively (HR 1.94, p < 0.001); high, intermediate and low prognostic groups had overall survival (OS) of 24.5, 8.9 and 3.4 months, respectively (HR 2.40, p < 0.001).

CONCLUSIONS

EPSILoN, combining five baseline clinical/blood parameters (ECOG PS, smoking, liver metastases, LDH, NLR), may help to identify advanced non-small-cell lung cancer (aNSCLC) patients who most likely benefit from immune checkpoint inhibitors (ICIs).