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

Comparative efficacy of immune checkpoint inhibitors combined with chemotherapy in patients with advanced driver-gene negative non-small cell lung cancer: A systematic review and network meta-analysis

Objective

To evaluate the efficacy of different combinations of immune checkpoint inhibitors (ICIs) and chemotherapy (CT) in the treatment of advanced non-small cell lung cancer (NSCLC).

Methods

We obtained relevant randomized controlled trials (RCTs) from databases such as PubMed, Embase, Web of Science, and The Cochrane Library up to May 31, 2023. The analysis of clinical prognostic factors was performed using R 4.2.3 and STATA 15.0. The main outcomes measured were overall survival (OS) and progression-free survival (PFS), while secondary outcomes included the objective response rate (ORR), disease control rate (DCR), and treatment-related adverse events of grade 3-5 severity (Grade ≥3 TRAE).

Results

A total of 17 randomized controlled trials (RCTs) were conducted between 2012 and 2023, involving 7792 patients. These trials evaluated 11 different treatment methods. The results of these trials showed that in terms of overall survival (OS) and progression-free survival (PFS), the combination of tislelizumab with chemotherapy and the combination of camrelizumab with chemotherapy were particularly effective. Moreover, when compared with other combination therapies, pembrolizumab combined with chemotherapy showed superiority in terms of disease control rate (DCR) and objective response rate (ORR). Subgroup analyses further demonstrated that the addition of immune checkpoint inhibitors (ICIs) to chemotherapy significantly improved PFS and OS in patients without liver metastasis and in those with brain metastasis. Additionally, carboplatin-based combination therapy was found to confer favorable survival benefits in terms of PFS, while cisplatin-based combination therapy showed the most favorable outcomes in terms of OS. The results of subgroup analyses for overall survival (OS) showed that the combination of immunotherapy and chemotherapy yielded positive outcomes in specific subgroups. These subgroups were characterized by PD-L1 Tumor Proportion Score (TPS) of 50 % or higher, usage of anti-PD-1 medications, age below 65, male gender, smoking history, and non-squamous cell carcinoma histology. Superior effectiveness was demonstrated only in extending the progression-free survival (PFS) of female patients and patients with squamous carcinoma. Meanwhile, other patient cohorts did not show the same level of improvement.

Conclusions

Tislelizumab, camrelizumab or pembrolizumab combined with chemotherapy may be the optimal first-line treatment strategies for NSCLC.

A Review of Recent Advances in the Molecular Mechanisms Underlying Brain Metastasis in Lung Cancer

Brain metastasis from lung cancer is a prevalent mode of treatment failure associated with a poor prognosis. The incidence of brain metastasis has recently shown a dramatic increase. The early detection and risk stratification of lung cancer-related brain metastasis would be highly advantageous for patients. However, our current knowledge and comprehension of the underlying mechanisms driving brain metastasis in lung cancer pose significant challenges. This review summarizes the mechanisms underlying brain metastasis, focusing on the intricate interplay between lung cancer-derived tumor cells and the unique characteristics of the brain, recent advancements in the identification of driver genes, concomitant genes, epigenetic features, including miRNAs and long noncoding RNAs, as well as the molecular characterization of brain metastasis originating from other organs, which may further enhance risk stratification and facilitate precise treatment strategies.

PD-(L)1 inhibitors plus bevacizumab and chemotherapy as first-line therapy in PD-L1-negative metastatic lung adenocarcinoma: a real-world data

BACKGROUND

Chemotherapy combined with immune checkpoint inhibitors (IC), bevacizumab (BC), or both (IBC) is the preferred first-line therapy for PD-L1-negative and oncogenic-driver wild-type metastatic lung adenocarcinoma. However, the optimal strategy is still undetermined.

METHODS

This retrospective study enrolled PD-L1-negative metastatic lung adenocarcinoma patients from four cancer centers between January 1, 2018 and June 30, 2022. All the patients received IC, BC, or IBC as the first-line therapies. The efficacy and safety were evaluated.

RESULTS

A total of 205 patients were included, with 60, 83, and 62 patients in IC, BC, and IBC groups, respectively. The baseline characteristics among three groups were well balanced. Patients treated with IBC had the highest objective response rate (ORR) (43.5%) and disease control rate (DCR) (100%) relative to those treated with IC (40.4%, 84.2%) or BC (40.5%, 96.2%) (ORR: P = 0.919, DCR: P < 0.01). Compared with the IC (6.74 m) or BC (8.28 m), IBC treatment significantly improved median progression-free survival (mPFS) (9.53 m, P = 0.005). However, no difference in overall survival (OS) was observed. When stratified by different clinical and molecular information, we found that male gender, ever smoking, wild-type genes mutations, and adrenal metastasis predict superior PFS benefit when treated with IBC. In patients with liver metastasis, IBC or BC treatment displayed better PFS compared with IC. No additional adverse reactions were observed in IBC group compared with other two groups.

CONCLUSION

Combined IBC treatment achieved superior DCR and PFS compared with IC or BC in patients with PD-L1-negative metastatic lung adenocarcinoma, while did not increase the adverse events.

Exploring the Molecular Tumor Microenvironment and Translational Biomarkers in Brain Metastases of Non-Small-Cell Lung Cancer

Brain metastases represent a significant clinical challenge in the treatment of non-small-cell lung cancer (NSCLC), often leading to a severe decline in patient prognosis and survival. Recent advances in imaging and systemic treatments have increased the detection rates of brain metastases, yet clinical outcomes remain dismal due to the complexity of the metastatic tumor microenvironment (TME) and the lack of specific biomarkers for early detection and targeted therapy. The intricate interplay between NSCLC tumor cells and the surrounding TME in brain metastases is pivotal, influencing tumor progression, immune evasion, and response to therapy. This underscores the necessity for a deeper understanding of the molecular underpinnings of brain metastases, tumor microenvironment, and the identification of actionable biomarkers that can inform multimodal treatment approaches. The goal of this review is to synthesize current insights into the TME and elucidate molecular mechanisms in NSCLC brain metastases. Furthermore, we will explore the promising horizon of emerging biomarkers, both tissue- and liquid-based, that hold the potential to radically transform the treatment strategies and the enhancement of patient outcomes.

A retrospective real-world study: the efficacy of immune-related combination therapies in advanced non-small cell lung cancer after resistance to EGFR-TKIs

BACKGROUND

Whether patients with advanced non-small cell lung cancer (NSCLC) should choose an immune-combination therapy regimen after EGFR-tyrosine kinase inhibitors (EGFR-TKIs) resistance is currently unclear.

METHODS

We evaluated 118 NSCLC patients treated by immune checkpoint inhibitors (ICIs) + chemotherapy (I + C), ICIs + chemotherapy + antiangiogenic therapy (I + C + A), chemotherapy + antiangiogenic therapy (C + A) after inefficacy of EGFR-TKIs. We assessed the objective remission rate (ORR), disease control rate (DCR), and progression-free survival (PFS) of these treatments.

RESULTS

The ORR was 26.1% vs 38.2% vs 16.3% in the three groups (P = 0.093). The divergence in DCR was also statistically significant (65.2% vs 85.3% vs 74.4%, P = 0.209). The median PFS was no statistically significant difference in PFS (3.09 vs 6.31 vs 5.91 months, P = 0.809), but the Kaplan-Meier survival curve of 12-month-PFS indicated an apparent survival advantage in the I + C + A group (P = 0.001). In addition, the I + C/I + C + A group showed higher median PFS than the C + A group in patients with brain metastases (median PFS, 6.44 vs 4.21 months, P = 0.022). The divergence in ORR of patients in the brain group was also statistically significant (P = 0.045). The I + C + A group showed superior efficacy in patients with liver metastases (median PFS, 0.95 vs 6.44 vs 3.48 months, P < 0.0001). The Cox proportional hazard modeling analysis suggested that the age, brain metastases, and liver metastases were all connected with the prognosis.

CONCLUSIONS

This study suggests that advanced NSCLC patients after resistance to EGFR-TKIs may achieve better outcomes from triple therapy. Patients with brain metastases favor ICIs-related combination therapies and patients with liver metastases prefer I + C + A therapy.

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.

Immunotherapy resistance in non-small-cell lung cancer: From mechanism to clinical strategies

The high primary resistance incidence and unavoidable secondary resistance are the major clinical obstacle to lasting long-term benefits in Non-small-cell lung cancer (NSCLC) patients treated with immunotherapy. The mechanisms of immunotherapy resistance in NSCLC are complex, mainly involving tumor cells and tumor microenvironment (TME) infiltrating immune cells, including TAMs, B cells, NK cells, and T cells. The selection of clinical strategies for NSCLC progression after immunotherapy resistance should depend on the progressive mode. The progression pattern of NSCLC patients after immunotherapy resistance can be divided into oligo-progression and systemic/multiple progression, which should be considered for further treatment selection. In the future, it needs to explore how to optimize the combined therapy and explore strategies to reprogram infiltrating immune cells under various genetic backgrounds of tumor cells and timely reshape TME during antitumor treatments.

BTK inhibitor combined with anti-PD-1 monoclonal antibody for the treatment of CD20-negative primary central nervous system lymphoma: A case report

CD20-negative diffuse large B-cell lymphoma (DLBCL) is a rare type of lymphoproliferative disorder characterized by a high degree of aggressiveness, a tendency for extranodal invasion and chemotherapeutic resistance. CD20-negative DLBCL originating from the nervous system is rarer. In primary central nervous system lymphoma (PCNSL), >90% of cases are histologically classified as DLBCL. The present study reports the case of a 65-year-old female with CD20-negative PCNSL, whose primary clinical symptom was a persistent headache. Serum tests for human immunodeficiency virus, Epstein-Barr virus-DNA, human herpesvirus 8, hepatitis B and hepatitis C were negative. Cranial magnetic resonance imaging suggested multiple intracranial occupancies. The neoplastic cells were found to be positive for CD19, CD79α, Bcl-2 (~92%) and c-Myc (~50%), while showing negative results for CD20, CD138, programmed cell death protein 1 (PD-1) and programmed cell death receptor 1 ligand 1 (PD-L1). The Ki-67 proliferation index was >80%. In the tumor microenvironment, <10% of the tumor-associated macrophages expressed PD-L1. The number of PD-1-positive tumor-infiltrating lymphocytes was 30-40 cells according to high-power field microscopy. The patient's disease progressed during methotrexate-based treatment, leading to a change in the treatment regimen to the Bruton tyrosine kinase inhibitor, zanubrutinib, combined with the anti-PD-1 monoclonal antibody tislelizumab. After two courses of the combined treatment, the patient achieved complete remission (CR) and continued to receive consolidation treatment. In the 20 months of follow-up since CR was achieved, the patient's general condition was good and the disease was in continuous remission. The present case report and literature review show that a combination of drugs targeting different mechanisms may be used to treat PCNSL to prolong patient survival time. The mechanism of the enhanced efficacy of a combination of the two drugs may be related to the enhancement of antitumor T-cell immune responses and reversal of T-cell immune metabolic dysfunctions by the inhibition of glycolysis.

RT-based combination therapy for brain metastasis from NSCLC with non-EGFR mutation/ALK gene rearrangement: A network meta-analysis

Introduction

Radiotherapy (RT) is currently the main treatment for brain metastases (BMs) from non-small cell lung cancer (NSCLC). Due to the short survival time and obvious adverse reactions of RT, we urgently need more appropriate treatment. This network meta-analysis reviewed the efficacy and adverse effects of radiotherapy-based combination therapy for patients without targeted epidermal growth factor receptor (EGFR) mutations/anaplastic lymphoma kinase (ALK) gene rearrangement NSCLC BMs, to screen out the therapy with the best efficacy.

Methods

PubMed, Embase, Web of Science, and Cochrane Library were searched from the earliest publication date available to 1 April 2022. STATA15.0 was used to conduct heterogeneity analysis, sensitivity analysis, forest plot analysis, and publication bias analysis.

Results

A total of 28 studies, involving 3707 patients were included in the Bayesian network meta-analysis. In the limited paired meta-analysis for head-to-head comparative trials, compared with RT-based combination therapy, RT combined with Immune checkpoint inhibitors (ICIs) showed significant overall survival (OS) benefit (HR 0.65, 95%CI 0.47–0.9, p&lt;0.01), RT combined with ICIs showed a non-significant difference for intracranial progression-free survival (iPFS) (HR 0.76, 95%CI 0.27–2.27, p&lt;0.01) and progression-free survival (PFS) (HR 0.9, 95%CI 0.36–2.37, p&lt;0.01). In addition, according to the ranking results, compared with RT combined with chemotherapy(CT) or with targeted therapy(TT), RT combined with ICIs might be the best treatment mode for OS(ICIs+RT vs CT+RT vs TT+RT; 91.9% vs. 27.8% vs. 29.3%, iPFS (ICIs+RT vs CT+RT vs TT+RT, 46.9% vs 25.2% vs 25.6%) and PFS (ICIs+RT vs CT+RT vs TT+RT, 36.2% vs 31% vs 36.5%).

Conclusions

RT combined with ICIs might be the best treatment mode to prolong the OS for BMs from NSCLC with non-EGFR mutation/ALK gene rearrangement.

Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022350065, identifier (CRD42022350065)

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.

Radiotherapy combined with PD-1/PD-L1 inhibitors in NSCLC brain metastases treatment: The mechanisms, advances, opportunities, and challenges

At present, whole-brain radiation therapy/stereotactic radiosurgery is one of the main local treatments for brain metastasis of non-small-cell lung cancer (NSCLC). Currently, it has been proved that radiotherapy (RT) can regulate the immune response, and small-sample studies have shown that patients with NSCLC brain metastases (BMs) can benefit from RT combined with immunotherapy (IO). However, the efficacy and safety of the combination treatment have not been deeply elaborated. Notably, as a challenge that is still being explored, the timing of RT combined with IO is likely to be an important factor affecting efficacy and prognosis. This article reviews the current application and challenges of RT combined with IO from the perspectives of molecular mechanism, combination timing, safety, and efficacy. The purpose is to provide information on clinical evidence-based medicine of combination between RT with IO. For further investigation, we also discuss the major challenges and prospects of RT combined with IO in NSCLC BMs.

Sensitive electrochemical immunosensor for CYFRA21-1 detection based on AuNPs@MoS2@Ti3C2Tx composites

Cytokeratin fragment antigen 21-1 (CYFRA21-1) is a sensitive marker for detecting non-small cell lung cancer (NSCLC). Ti₃C₂T_x modified by gold nanoparticles (AuNPs) and molybdenum disulfide (MoS₂) were synthesized for the first time to obtain the AuNPs@MoS₂@Ti₃C₂T_x composites, which have large specific surface area and good electrocatalytic properties. A novel electrochemical immunoassay for sensitive detection of CYFRA21-1 was developed by loading a large quantity of secondary antibodies (Ab₂) and toluidine blue (TB) on the surface of the material as signal probe, and Nafion-AuNPs mixture as electrode material. When the electrochemical response value of CYFRA21-1 increased linearly within the concentration range of 0.5 pg mL^-1-50 ng mL^-1, the detection limit can reach as low as 0.03 pg mL^-1. In addition, the experimental results showed that the biosensor had the potential to rapidly detect CYFRA21-1 in the complex samples such as patient serum, and had a broad application prospect in the early diagnosis and monitoring of NSCLC.

Modulation of the blood-tumor barrier to enhance drug delivery and efficacy for brain metastases

The blood-brain barrier is the selectively permeable vasculature of the brain vital for maintaining homeostasis and neurological function. Low permeability is beneficial in the presence of toxins and pathogens in the blood. However, in the presence of metastatic brain tumors, it is a challenge for drug delivery. Although the blood-tumor barrier is slightly leaky, it still is not permissive enough to allow the accumulation of therapeutic drug concentrations in brain metastases. Herein, we discuss the differences between primary brain tumors and metastatic brain tumors vasculature, effects of therapeutics on the blood-tumor barrier, and characteristics to be manipulated for more effective drug delivery.

Future of PD-1/PD-L1 axis modulation for the treatment of triple-negative breast cancer

Triple-negative breast cancer (TNBC) has the worst prognosis among the subtypes of breast cancer, with no targeted therapy available. Immunotherapy targeting programmed cell death protein-1 (PD-1) and its ligand (PD-L1) has resulted in some promising outcomes in cancer patients. The common treatments are monoclonal antibodies (mAbs). Despite novel methodologies in developing mAbs, there are several drawbacks with these medications. Immunological reactions, expensive and time-consuming production and requiring refrigeration are some of the challenging characteristics of mAbs that are addressed with using aptamers. Aptamers are nucleotide-based structures with high selectivity and specificity for target. Their small size helps aptamers penetrate the tissue better. In this review, we have discussed the nature of PD-1/PD-L1 interaction and summarised the available mAbs and aptamers specific for these two targets. This review highlights the role of aptamers as a future pathway for PD-1/PD-L1 modulation.

Efficacy of PD-1/L1 inhibitors in brain metastases of non-small-cell lung cancer: pooled analysis from seven randomized controlled trials

Background: The efficacy of PD-1 or PD-L1 inhibitors in patients with brain metastases of non-small-cell lung cancer (BM-NSCLC) is inconclusive. Materials & methods: An electronic search was performed. Randomized controlled trials RCTs that compared the efficacy of PD-1- or PD-L1-inhibitor-based regimens with non-PD-1/L1 inhibitor regimens in patients with NSCLC and reported the data of subgroup patients with brain metastases were eligible for inclusion. The hazard ratios (HRs) for progression-free survival and overall survival were pooled in BM-NSCLC. Results: Seven RCTs with 472 BM-NSCLC cases are included. The pooled HRs indicated that PD-1 or PD-L1 inhibitor-based regimens reduced risk of disease progression by 44% and reduced risk of death of BM-NSCLC patients by 29% compared with non-PD-1/L1 inhibitor regimens. Conclusion: This meta-analysis indicates that PD-1 or PD-L1 inhibitors can reduce risk of both disease progression and death of patients with brain metastases of NSCLC, who have been pretreated with local therapies and/or are asymptomatic for the brain lesions.