Sequential Cytokine-Induced Killer Cell Immunotherapy Enhances the Efficacy of the Gemcitabine Plus Cisplatin Chemotherapy Regimen for Metastatic Nasopharyngeal Carcinoma

Immunotherapy for recurrent or metastatic nasopharyngeal carcinoma

Immunotherapy, particularly immune checkpoint inhibitors (ICIs), such as anti-programmed death 1/programmed death-ligand 1 (PD-1/PD-L1) therapy, has emerged as a pivotal treatment modality for solid tumors, including recurrent or metastatic nasopharyngeal carcinoma (R/M-NPC). Despite the advancements in the utilization of ICIs, there is still room for further improving patient outcomes. Another promising approach to immunotherapy for R/M-NPC involves adoptive cell therapy (ACT), which aims to stimulate systemic anti-tumor immunity. However, individual agent therapies targeting dendritic cells (DCs) appear to still be in the clinical trial phase. This current review underscores the potential of immunotherapy as a valuable adjunct to the treatment paradigm for R/M-NPC patients. Further research is warranted to enhance the efficacy of immunotherapy through the implementation of strategies such as combination therapies and overcoming immune suppression. Additionally, the development of a biomarker-based scoring system is essential for identifying suitable candidates for precision immunotherapy.

Efficacy and Safety of Cell-based Immunotherapy in The Treatment of Recurrent or Metastatic Nasopharyngeal Carcinoma - A Systematic Review and Meta-analysis

BACKGROUND

Recurrent/Metastatic Nasopharyngeal Carcinoma (RM-NPC) remains difficult to treat and contributes to considerable mortality. The first-line treatment for RM-NPC is Gemcitabine and Cisplatin and second-line treatment options differ. The endemic variant of NPC is associated with Epstein-Barr Virus (EBV). Therefore, Cell-based Immunotherapy (CBI) targeting EBV-specific RM-NPC may be effective.

METHODS

We systematically searched PubMed, Embase and the Cochrane Library for randomised or observational studies investigating the efficacy and safety of CBI in the treatment of RM-NPC. We performed all meta-analyses using the random-effects model. Studies were further stratified by endemicity, nature of disease and drug type to investigate for potential between-study heterogeneity and additional pre-specified tests were employed to assess for publication bias.

RESULTS

We screened 1,671 studies and included 13 studies with 403 participants in the systematic review, of which nine studies were eligible for meta-analysis. The use of CBI monotherapy as second or subsequent line treatment for EBV-positive RM-NPC revealed an ORR of 10 % (95 %CI = 3 %-29 %), median PFS of 2.37 months (95 %CI = 1.23-3.51) and median OS of 10.16 months (95 %CI = 0.67-19.65). For EBV-specific Cytotoxic T-Lymphocyte monotherapy, the pooled PD rate was 54 % (95 %CI = 9 %-93 %), SD rate was 22 % (95 %CI = 2 %-75 %) and incidence rate of any grade adverse events was 45 %. For Dendritic Cell monotherapy, a PD rate of 80 % (95 % CI = 29 %-98 %), SD rate of 11 % (95 % CI = 0 %-82 %) and incidence rate of any grade adverse events of 29 % was achieved.

CONCLUSION

CBI monotherapy demonstrates some activity in pre-treated RM-NPC. More trials are needed to better understand how to integrate CBI into RM-NPC care.

Safety of dendritic cell and cytokine-induced killer (DC-CIK) cell-based immunotherapy in patients with solid tumor: a retrospective study in China

Systematic assessment of adverse side effects of Adoptive T cell therapy, especially cytokine-induced killer cell and dendric cell treatment Dendritic cells-Cytokine-induced killer (DC-CIK) therapy, especially when combined with chemotherapy, has not been reported. Totally 1100 consecutive patients (2504 trail cycles) enrolled in DC-CIK treatment trials at Beijing Shijitian Hospital between August 2012 and August 2022 were retrospectively reviewed. The 370 patients (34%)/815 cycles enrolled in our trial combined with chemotherapy. In total, 548 (cases)/870 (cycles) patients experienced AEs. The AE class was mainly composed of Neurological 34 cycles (4%), Musculoskeletal 28 cycles (3%), Immunopathies 5 cycles (1%), Hematological 521 cycles (60%), 224 general disorders and administration site conditions cycles (26%), Gastrointestinal 209 cycles (24%), Skin 15 cycles (2%), and 119 Metabolism and Nutrition disorders cycles (14%). The AE class of gastrointestinal (vomiting, P=0.025), nutritional (anorexia, P=0.016), and hematological disorders (anemia P<0.0001, leukopenia P<0.0001) appeared in the DC-CIK treatment and were mainly correlated with chemotherapy. Multiple logistic regression analysis suggested that regardless of whether DC-CIK was combined with chemotherapy, multi-line treatment was more prone to nausea, anorexia, fatigue, anemia, and leukopenia than first-line treatment. However, correlation analysis verified that increasing the number of cycles of DC-CIK treatment alone could reduce the incidence rate of fatigue (P=0.001), anorexia (P<0.0001), and anxiety (P=0.01). Most of the adverse side effects that occurred during autologous DC-CIK treatment were associated with combined or previously applied chemotherapeutic treatment, which also indicated that autologous DC-CIK anti-tumor therapy was safe.

How can Cytokine-induced killer cells overcome CAR-T cell limits

The successful treatment of patients affected by B-cell malignancies with Chimeric Antigen Receptor (CAR)-T cells represented a breakthrough in the field of adoptive cell therapy (ACT). However, CAR-T therapy is not an option for every patient, and several needs remain unmet. In particular, the production of CAR-T cells is expensive, labor-intensive and logistically challenging; additionally, the toxicities deriving from CAR-T cells infusion, such as cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS), have been documented extensively. Alternative cellular therapy products such as Cytokine-induced killer (CIK) cells have the potential to overcome some of these obstacles. CIK cells are a heterogeneous population of polyclonal CD3+CD56+ T cells with phenotypic and functional properties of NK cells. CIK cell cytotoxicity is exerted in a major histocompatibility complex (MHC)-unrestricted manner through the engagement of natural killer group 2 member D (NKG2D) molecules, against a wide range of hematological and solid tumors without the need for prior antigen exposure or priming. The foremost potential of CIK cells lies in the very limited ability to induce graft-versus-host disease (GvHD) reactions in the allogeneic setting. CIK cells are produced with a simple and extremely efficient expansion protocol, which leads to a massive expansion of effector cells and requires a lower financial commitment compared to CAR-T cells. Indeed, CAR-T manufacturing involves the engineering with expensive GMP-grade viral vectors in centralized manufacturing facilities, whereas CIK cell production is successfully performed in local academic GMP facilities, and CIK cell treatment is now licensed in many countries. Moreover, the toxicities observed for CAR-T cells are not present in CIK cell-treated patients, thus further reducing the costs associated with hospitalization and post-infusion monitoring of patients, and ultimately encouraging the delivery of cell therapies in the outpatient setting. This review aims to give an overview of the limitations of CAR-T cell therapy and outline how the use of CIK cells could overcome such drawbacks thanks to their unique features. We highlight the undeniable advantages of using CIK cells as a therapeutic product, underlying the opportunity for further research on the topic.

Immunotherapy for nasopharyngeal carcinoma: Current status and prospects (Review)

Nasopharyngeal carcinoma (NPC) is an epithelial tumor located in the nasopharynx and is highly associated with Epstein‑Barr virus (EBV) infection. Although radiotherapy alone can cure ~90% of patients with early‑stage disease, >70% of patients with NPC have locoregionally advanced or metastatic disease at the first diagnosis due to the insidious and aggressive nature of NPC. After comprehensive radiochemotherapy, 20‑30% of patients with advanced NPC still fail treatment, mainly due to recurrence and/or metastasis (R/M). Conventional salvage treatments, such as radiotherapy, chemotherapy and surgery, are suboptimal and frequently accompanied by severe adverse effects and limited efficacy. In recent years, immunotherapy has emerged as a promising treatment modality for R/M NPC. An increasing number of clinical studies have investigated the safety and efficacy of immunotherapy for advanced NPC and have shown considerable progress. In the present review, the rationale for the use of immunotherapy to treat NPC was summarized and the current status, progress and challenges of NPC clinical research on different immunotherapeutic approaches were highlighted, including immune checkpoint inhibitors, vaccines, immunomodulators, adoptive cell transfer and EBV‑specific monoclonal antibodies. The comprehensive overview of immunotherapy in NPC may provide insight for clinical practice and future investigation.

Nasopharyngeal Carcinoma and Its Microenvironment: Past, Current, and Future Perspectives

Nasopharyngeal carcinoma (NPC) is an epithelial malignancy that raises public health concerns in endemic countries. Despite breakthroughs in therapeutic strategies, late diagnosis and drug resistance often lead to unsatisfactory clinical outcomes in NPC patients. The tumor microenvironment (TME) is a complex niche consisting of tumor-associated cells, such as fibroblasts, endothelial cells, leukocytes, that influences tumor initiation, progression, invasion, and metastasis. Cells in the TME communicate through various mechanisms, of note, exosomes, ligand-receptor interactions, cytokines and chemokines are active players in the construction of TME, characterized by an abundance of immune infiltrates with suppressed immune activities. The NPC microenvironment serves as a target-rich niche for the discovery of potential promising predictive or diagnostic biomarkers and the development of therapeutic strategies. Thus, huge efforts have been made to exploit the role of the NPC microenvironment. The whole picture of the NPC microenvironment remains to be portrayed to understand the mechanisms underlying tumor biology and implement research into clinical practice. The current review discusses the recent insights into the role of TME in the development and progression of NPC which results in different clinical outcomes of patients. Clinical interventions with the use of TME components as potential biomarkers or therapeutic targets, their challenges, and future perspectives will be introduced. This review anticipates to provide insights to the researchers for future preclinical, translational and clinical research on the NPC microenvironment.

Nasopharyngeal carcinoma: an evolving paradigm

The past three decades have borne witness to many advances in the understanding of the molecular biology and treatment of nasopharyngeal carcinoma (NPC), an Epstein-Barr virus (EBV)-associated cancer endemic to southern China, southeast Asia and north Africa. In this Review, we provide a comprehensive, interdisciplinary overview of key research findings regarding NPC pathogenesis, treatment, screening and biomarker development. We describe how technological advances have led to the advent of proton therapy and other contemporary radiotherapy approaches, and emphasize the relentless efforts to identify the optimal sequencing of chemotherapy with radiotherapy through decades of clinical trials. Basic research into the pathogenic role of EBV and the genomic, epigenomic and immune landscape of NPC has laid the foundations of translational research. The latter, in turn, has led to the development of new biomarkers and therapeutic targets and of improved approaches for individualizing immunotherapy and targeted therapies for patients with NPC. We provide historical context to illustrate the effect of these advances on treatment outcomes at present. We describe current preclinical and clinical challenges and controversies in the hope of providing insights for future investigation.

Immunotherapeutic approaches in nasopharyngeal carcinoma

Introduction: Nasopharyngeal carcinoma (NPC) is endemic in Southern China and Southeast Asia. Epstein-Barr virus (EBV) represents a unique etiological culprit in the poorly differentiated nonkeratinizing and undifferentiated subtypes. EBV antigens are expressed on tumor cells albeit in a restricted manner. Treatment options for recurrent or metastatic disease are limited. Nevertheless, emerging data from immunotherapy studies in NPC have shed light into their potential antitumor efficacy. Areas covered: This article reviews existing clinical evidence for different immunotherapeutic approaches for NPC, including adoptive cellular therapy, therapeutic cancer vaccines, and immune checkpoint inhibitors. Expert opinion: There is a growing understanding on EBV virology and the immune evasion mechanisms in NPC. Immunotherapeutic strategies leveraging these properties have shown encouraging efficacy and safety results in early-phase clinical studies. Moving forward, areas to be addressed include appropriate patient selection, optimal incorporation into standard treatment paradigms, biomarker identification, as well as the development of scalable and reproducible immune product generation processes.

Interferon β and Anti-PD-1/PD-L1 Checkpoint Blockade Cooperate in NK Cell-Mediated Killing of Nasopharyngeal Carcinoma Cells

Nasopharyngeal carcinoma (NPC) is a highly malignant epithelial cancer linked to EBV infection. Addition of interferon-β (IFNβ) to chemo- and radiochemotherapy has led to survival rates >90% in children and adolescents. As NPC cells are sensitive to apoptosis via tumor necrosis factor-related apoptosis inducing ligand (TRAIL), we explored the role of TRAIL and IFNβ in the killing of NPC cells by natural killer (NK) cells. NPC cells, including cells of a patient-derived xenograft were exposed to NK cells in the presence or absence of IFNβ. NK cells killed NPC- but not nasoepithelial cells and killing was predominately mediated via TRAIL. Incubation of NK cells with IFNβ increased cytotoxicity against NPC cells. Concomitant incubation of NK- and NPC cells with IFNβ before coculture reduced cytotoxicity and could be overcome by blocking the PD-1/PD-L1 axis leading to the release of intracellular TRAIL from NK cells. In conclusion, combination of IFNβ and anti-PD-1, augmenting cytotoxicity of NK cells against NPC cells, could be a strategy to improve NPC-directed therapy and warrants further evaluation in vivo.

Clinical Effect of Adjuvant Cytokine-Induced Killer Cells Immunotherapy in Patients with Stage II-IVB Nasopharyngeal Carcinoma after Chemoradiotherapy: A propensity score analysis

As an adjuvant immunotherapy, cytokine-induced killer cells (CIKs) infusion has been demonstrated to exert potent effectiveness in several types of cancer patients who received curative treatment. However, controversy exists regarding whether nasopharyngeal carcinoma (NPC) patients can benefit from additional treatment after radical radiotherapy or chemoradiotherapy to improve their distant control and survival. In this retrospective study, we aimed to evaluate the efficacy of adjuvant CIK cells therapy in NPC patients with stage II-IVB after curative treatment. From January 1, 2005 to December 31, 2012, 85 pairs of NPC patients matching by propensity score matching (PSM) method to balance prognostic factors were included in this study: 85 cases underwent radical treatment, 85 cases received radical treatment and sequential CIKs infusion. We found that disease-free survival (DFS) and overall survival (OS) were significantly better in the CIK group than that in the control group (P = 0.009, P < 0.001, respectively). Adjuvant CIK cells immunotherapy was showed to be an independent prognostic factor for survival of the patients in further multivariate analysis. In subgroup analyses, the DFS and OS of patients with T3/4, III and IV A-B TNM (tumor-node-metastasis) stages were significantly enhanced in CIK group compared to control group. Nevertheless, both NPC patients with high and low EBV DNA benefited from adjuvant CIK cells immunotherapy. In conclusion, CIKs infusion is an effective adjuvant immunotherapy for enhancing the prognosis of NPC patients who have received the standard treatment, particularly for those with more aggressive tumor (T3/4) or advanced TNM stage.

MicroRNA-153 affects nasopharyngeal cancer cell viability by targeting TGF-β2

The aim of the present study was to determine the function of microRNA-153 (miR-153) in the viability of nasopharyngeal cancer (NPC) cells and determine the underlying molecular mechanism. The expression of miR-153 in patients with NPC was markedly decreased compared with that in paracarcinoma tissue. miR-153 upregulation observably decreased cell viability, induced apoptosis, increased caspase-3 and -9 activity, and increased the B-cell lymphoma 2 (Bcl-2)-associated X protein/Bcl-2 protein expression ratio in 13-9B cells. miR-153 upregulation also suppressed transforming growth factor-β₂ (TGF-β₂) and Smad2 protein expression in 13-9B cells. TGF-β₂ inhibitor enhanced the effect of miR-153 upregulation on the inhibition of cell viability, induction of apoptosis, increase in caspase-3 and -9 activity, and increase in Bax/Bcl-2 protein expression ratio in 13-9B cells. The results of the present study indicate that miR-153 affects the progression of NPC by targeting the TGF-β₂/Smad2 signaling pathway.

Trial Watch: Adoptively transferred cells for anticancer immunotherapy

Immunotherapies aimed at strengthening immune effector responses against malignant cells are growing at exponential rates. Alongside, the impressive benefits obtained by patients with advanced melanoma who received adoptively transferred tumor-infiltrating lymphocytes (TILs) have encouraged the scientific community to pursue adoptive cell transfer (ACT)-based immunotherapy. ACT involves autologous or allogenic effector lymphocytes that are generally obtained from the peripheral blood or resected tumors, expanded and activated ex vivo, and administered to lymphodepleted patients. ACT may be optionally associated with chemo- and/or immunotherapeutics, with the overall aim of enhancing the proliferation, persistence and functionality of infused cells, as well as to ensure their evolution in an immunological permissive local and systemic microenvironment. In addition, isolated lymphocytes can be genetically engineered to endow them with the ability to target a specific tumor-associated antigen (TAA), to increase their lifespan, and/or to reduce their potential toxicity. The infusion of chimeric antigen receptor (CAR)-expressing cytotoxic T lymphocytes redirected against CD19 has shown promising clinical efficacy in patients with B-cell malignancies. Accordingly, the US Food and Drug Administration (FDA) has recently granted 'breakthrough therapy' designation to a CAR-based T-cell therapy (CTL019) for patients with B-cell malignancies. Considerable efforts are now being devoted to the development of efficient ACT-based immunotherapies for non-hematological neoplasms. In this Trial Watch, we summarize recent clinical advances on the use of ACT for oncological indications.

Cell-based immunotherapy with cytokine-induced killer (CIK) cells: From preparation and testing to clinical application

Cell-based immunotherapy holds promise in the quest for the treatment of cancer, having potential synergy with surgery, chemotherapy and radiotherapy. As a novel approach for adoptive cell-based immunotherapy, cytokine-induced killer (CIK) cells have moved from the 'bench to bedside'. CIK cells are a heterogeneous subset of ex-vitro expanded, polyclonal T-effector cells with both natural killer (NK) and T-cell properties, which present potent non-major histocompatibility complex-restricted cytotoxicity against a variety of tumor target cells. Initial clinical studies on CIK cell therapy have provided encouraging results and revealed synergistic antitumor effects when combined with standard therapeutic procedures. At the same time, issues such as inadequate quality control and quantity of CIK cells as well as exaggerated propaganda were continuously emerging. Thus, the Ministry of Health in China stopped CIK cell therapy in May 2016, which was a major setback for the innovation of CIK cell-based immunotherapy. Thus, it is very important to modify technical criteria to develop a standardized operation procedure (SOP) and standardized system for evaluating antitumor efficacy in a safe way.

KRAS mutation-induced upregulation of PD-L1 mediates immune escape in human lung adenocarcinoma

It was reported that PD-L1 expression was correlated with genetic alterations. Whether PD-L1 was regulated by mutant Kirsten rat sarcoma viral oncogene homolog (KRAS) in non-small-cell lung cancer (NSCLC) and the underlying molecular mechanism were largely unknown. In this study, we investigated the correlation between PD-L1 expression and KRAS mutation and the functional significance of PD-1/PD-L1 blockade in KRAS-mutant lung adenocarcinoma. We found that PD-L1 expression was associated with KRAS mutation both in the human lung adenocarcinoma cell lines and tissues. PD-L1 was up-regulated by KRAS mutation through p-ERK but not p-AKT signaling. We also found that KRAS-mediated up-regulation of PD-L1 induced the apoptosis of CD3-positive T cells which was reversed by anti-PD-1 antibody (Pembrolizumab) or ERK inhibitor. PD-1 blocker or ERK inhibitor could recover the anti-tumor immunity of T cells and decrease the survival rates of KRAS-mutant NSCLC cells in co-culture system in vitro. However, Pembrolizumab combined with ERK inhibitor did not show synergistic effect on killing tumor cells in co-culture system. Our study demonstrated that KRAS mutation could induce PD-L1 expression through p-ERK signaling in lung adenocarcinoma. Blockade of PD-1/PD-L1 pathway may be a promising therapeutic strategy for human KRAS-mutant lung adenocarcinoma.

Identifying pretreatment baseline factors predictive of distant metastasis in patients with nasopharyngeal carcinoma after radiotherapy

This retrospective study was performed to identify pretreatment baseline factors that could predict the development of distant metastasis (DM) in patients with nasopharyngeal carcinoma (NPC).A cohort of 119 NPC patients undergoing radiotherapy (RT) or chemoradiotherapy (CRT) were recruited into the study. Among them, 51 developed DM (DM group) within 3 years after treatment and 68 did not (DM-free group). Various clinicopathological factors were measured before the treatment and analyzed by univariate as well as multivariate analyses for the potential correlation with DM development.Univariate analysis revealed that increased peripheral lactate dehydrogenase (LDH) level, lower lymphocyte-monocyte ratio (LMR), higher neutrophil-lymphocyte ratio (NLR), advanced American Joint Committee on Cancer (AJCC) stage, advanced T stage, and advanced N stage were significantly correlated with the presence of DM. Multivariate analysis identified advanced AJCC stage and high LDH level were independent predictive factors for DM.Routinely measured pretreatment clinical factors, including AJCC state and serum LDH level, could independently predict DM. These factors will benefit the selection of appropriate treatment options and improve the overall survival of NPC patients.

Current update of adoptive immunotherapy using cytokine-induced killer cells to eliminate malignant gliomas

The therapeutic outcome for those with malignant glioma is poor, even though diverse therapeutic modalities have been developed. Immunotherapy has emerged as a therapeutic approach for malignant gliomas, making it possible to selectively treat tumors while sparing normal tissue. Here, we review clinical trials of adoptive immunotherapy approaches for malignant gliomas. We also describe a clinical trial that examined the efficacy and safety of autologous cytokine-induced killer (CIK) cells along with concomitant chemoradiotherapy for newly diagnosed glioblastoma. These CIK cells identify and kill autologous tumor cells. This review focuses on the use of adoptive immunotherapy for malignant gliomas and reviews the current literature on the concept of antitumor activity mediated by CIK cells.

Chemotherapy with or without autologous cytokine-induced killer cell transfusion as the first-line treatment for stage IV gastrointestinal cancer: a phase II clinical trial

OBJECTIVE

To investigate the efficacy of autologous cytokine-induced killer (CIK) cell therapy combined with chemotherapy versus chemotherapy alone for the treatment of stage IV gastrointestinal (GI) cancer in the first-line setting.

METHODS

Thirty-three patients diagnosed with stage IV GI cancer were divided into chemotherapy plus CIK group (chemo-CIK, n = 16) and chemotherapy-alone group (chemo-alone, n = 17). Autologous peripheral blood mononuclear cells were separated by flow cytometry, cultured in vitro to induce CIK cells, and transfused into patients on days 14 and 16 of the first and second chemotherapy cycles.

RESULTS

The median progression-free survival (PFS) was 5.6 months for patients in the chemo-CIK group and 3.83 months for those in the chemo-alone group. The difference was borderline significant (P = 0.06), indicating a potential advantage for combined CIK cell transfusion with chemotherapy in improving PFS. A favored objective response rate was also observed in the chemo-CIK group than in the chemo-alone group. This study also revealed that CIK cell transfusion restored the cellular immunity in these GI cancer patients. The percentage of natural killer T cells, NK cells, CD3(+) T cells, and T-cell subgroups CD4(+) proportion in the peripheral blood of cancer patients significantly increased after the CIK cell transfusion, while the change in T-cell subgroups CD8(+) and CD4(+)/CD8(+) did not differ significantly.

CONCLUSIONS

The study showed that the addition of CIK cell transfusion to traditional chemotherapy in the first-line setting was associated with a prolonged PFS and enhanced T-lymphocyte subset activity, supporting a potential treatment choice for advanced GI cancer patients.

Upregulation of PD-L1 by EML4-ALK fusion protein mediates the immune escape in ALK positive NSCLC: Implication for optional anti-PD-1/PD-L1 immune therapy for ALK-TKIs sensitive and resistant NSCLC patients

Driver mutations were reported to upregulate programmed death-ligand 1 (PD-L1) expression. However, how PD-L1 expression and immune function was affected by ALK-TKIs and anti-PD-1/PD-L1 treatment in ALK positive non-small-cell lung cancer (NSCLC) remains poorly understood. In the present study, western-blot, real-time PCR, flow cytometry and immunofluorescence were employed to explore how PD-L1 was regulated by ALK fusion protein. ALK-TKIs and relevant inhibitors were used to identify the downstream signaling pathways involved in PD-L1 regulation. Cell apoptosis, viability and Elisa test were used to study the immune suppression by ALK activation and immune reactivation by ALK-TKIs and/or PD-1 blocking in tumor cells and DC-CIK cells co-culture system. We found that PD-L1 expression was associated with EGFR mutations and ALK fusion genes in NSCLC cell lines. Over-expression of ALK fusion protein increased PD-L1 expression. PD-L1 mediated by ALK fusion protein increased the apoptosis of T cells in tumor cells and DC-CIK cells co-culture system. Inhibiting ALK by sensitive TKIs could enhance the production of IFNγ. Anti-PD-1 antibody was effective in both crizotinib sensitive and resistant NSCLC cells. Synergistic tumor killing effects were not observed with ALK-TKIs and anti-PD-1 antibody combination in co-culture system. ALK-TKIs not only directly inhibited tumor viability but also indirectly enhanced the antitumor immunity via the downregulation of PD-L1. Anti-PD-1/PD-L1 antibodies could be an optional therapy for crizotinib sensitive, especially crizotinib resistant NSCLC patients with ALK fusion gene. Combination of ALK-TKIs and anti-PD-1/PD-L1 antibodies treatment for ALK positive NSCLC warrants more data before moving into clinical practice.