Specific targeting of cancer stem cells by immunotherapy: A possible stratagem to restrain cancer recurrence and metastasis

Cancer stem cells (CSCs), the tumor-initiating cells playing a crucial role in cancer progression, recurrence, and metastasis, have the intrinsic property of self-renewal and therapy resistance. The tumorigenic properties of these cells include generation of cellular heterogeneity and immuno-suppressive tumor microenvironment (TME), conferring them the capability to resist a variety of anti-cancer therapeutics. Further, CSCs possess several unique immunological properties that help them escape recognition by the innate and adaptive immune system and shape a TME into a pro-tumorigenic and immunosuppressive landscape. In this context, immunotherapy is considered one of the best therapeutic options for eliminating CSCs to halt cancer recurrence and metastasis. In this review, we discuss the various immunomodulatory properties of CSCs and the interaction of CSCs with the immune system enabling immune evasion. In addition, we also highlight the present research update on immunotherapeutic targeting of CSCs and the possible further scope of research on this topic. We believe that a deeper understanding of CSCs' immunological properties and the crosstalk between CSCs and the immune system can develop better innovative immune-therapeutics and enhance the efficacy of current therapy-resistant cancer treatments.

First-Line ICI Monotherapies for Advanced Non-small-cell Lung Cancer Patients With PD-L1 of at Least 50%: A Cost-Effectiveness Analysis

Objective: Three immune checkpoint inhibitors (ICIs), pembrolizumab, atezolizumab and cemiplimab, have been successively approved as first-line treatments for advanced non-small-cell lung cancer (NSCLC) patients with programmed cell death ligand 1(PD-L1) expression of at least 50%. This study was designed to compare the cost-effectiveness of these three novel therapies in this patient population.

Material and Methods: Using Markov model and network meta-analysis, we conducted separate cost-effectiveness analyses for cemiplimab, pembrolizumab and atezolizumab among advanced NSCLC patients with PD-L1 of at least 50% from the United States health care sector perspective. Health states included progression-free survival, progressive disease, end-stage disease, and death. Clinical efficacy and safety data were derived from phase III clinical trials and health state utilities and costs data were collected from published resources. Two scenario analyses were conducted to assess the impact of varying subsequent anticancer therapies on the cost-effectiveness of these 3 ICIs and cost-effectiveness of pembrolizumab combined with chemotherapy versus these 3 first-line ICI monotherapies.

Results: In base case analysis, cemiplimab compared with pembrolizumab was associated with a gain of 0.44 quality-adjusted life-years (QALYs) and an increased cost of $23,084, resulting in an incremental cost-effectiveness ratio (ICER) of $52,998/QALY; cemiplimab compared with atezolizumab was associated with a gain of 0.13 QALYs and a decreased cost of $104,642, resulting in its dominance of atezolizumab. The first scenario analysis yielded similar results as our base case analysis. The second scenario analysis founded the ICERs for pembrolizumab plus chemotherapy were $393,359/QALY, $190,994/QALY and $33,230/QALY, respectively, compared with cemiplimab, pembrolizumab and atezolizumab.

Conclusion: For advanced NSCLC patients with PD-L1 of at least 50%, cemiplimab was a cost-effective option compared with pembrolizumab and a dominant alternative against atezolizumab. Our scenario analysis results supported the cemiplimab plus chemotherapy as a second-line therapy and suggested an extended QALY but overwhelming cost linking to pembrolizumab plus chemotherapy.

Current status and quality of radiomic studies for predicting immunotherapy response and outcome in patients with non-small cell lung cancer: a systematic review and meta-analysis

PURPOSE

Prediction of immunotherapy response and outcome in patients with non-small cell lung cancer (NSCLC) is challenging due to intratumoral heterogeneity and lack of robust biomarkers. The aim of this study was to systematically evaluate the methodological quality of radiomic studies for predicting immunotherapy response or outcome in patients with NSCLC.

METHODS

We systematically searched for eligible studies in the PubMed and Web of Science datasets up to April 1, 2021. The methodological quality of included studies was evaluated using the phase classification criteria for image mining studies and the radiomics quality scoring (RQS) tool. A meta-analysis of studies regarding the prediction of immunotherapy response and outcome in patients with NSCLC was performed.

RESULTS

Fifteen studies were identified with sample sizes ranging from 30 to 228. Seven studies were classified as phase II, and the remaining as discovery science (n = 2), phase 0 (n = 4), phase I (n = 1), and phase III (n = 1). The mean RQS score of all studies was 29.6%, varying from 0 to 68.1%. The pooled diagnostic odds ratio for predicting immunotherapy response in NSCLC using radiomics was 14.99 (95% confidence interval [CI] 8.66-25.95). In addition, radiomics could divide patients into high- and low-risk group with significantly different overall survival (pooled hazard ratio [HR]: 1.96, 95%CI 1.61-2.40, p < 0.001) and progression-free survival (pooled HR: 2.39, 95%CI 1.69-3.38, p < 0.001).

CONCLUSIONS

Radiomics has potential to noninvasively predict immunotherapy response and outcome in patients with NSCLC. However, it has not yet been implemented as a clinical decision-making tool. Further external validation and evaluation within clinical pathway can facilitate personalized treatment for patients with NSCLC.

The Immunostimulative Effect and Mechanisms of a Novel Mouse Anti-Human PD-1 Monoclonal Antibody on Jurkat Lymphocytic Cells Cocultured with Hepatoma Cells

Background

Monoclonal antibodies (mAbs) that target the programmed cell death-1 (PD-1)/programmed death-ligand 1 (PD-L1) immune checkpoint have demonstrated substantial clinical benefit for a variety of solid tumors. However, their applications in patients with hepatocellular carcinoma (HCC) are reported with unclear molecular mechanisms. Here, we report a novel mouse anti-human PD-1 mAb that can reverse the immunosuppressive effect of HePG2 cells on Jurkat cells.

Materials and Methods

HepG2 liver cancer cells, which were induced to overexpress PD-L1 by IFN-γ, were co-cultured with PHA-activated Jurkat lymphocytic cells to investigate the immunostimulative effect and mechanisms of the 14 newly generated PD-1 mAbs. Multiple cellular and molecular biology experiments were performed in this study, such as CCK-8, ELISA, flow cytometry, immunofluorescence and Western blot.

Results

We found that mAb B1C4 significantly enhanced the tumor-killing cytokine secretion level by Jurkat cells in the co-culture system and increased the killing ability of Jurkat cells on HepG2 cells. Co-culture with HePG2 cells led to Jurkat cell cycle delay in S phase, and B1C4 promoted cell cycle progression from S to G2/M. Co-culture with HePG2 cells also caused apoptosis in Jurkat cells, which was inhibited by B1C4. B1C4 reversed the immunosuppression of Jurkat cells resulted from co-cultured with HePG2 cells through inhibiting PTEN and activating PI3K/AKT/mTOR signaling pathways.

Conclusion

Our study demonstrated that anti-PD-1 mAb B1C4 could inhibit the apoptosis of Jurkat cells induced by HePG2 hepatoma cells and reverse the immunosuppressive effect of HePG2 cells on Jurkat cells. The study provides a vital basis for applying PD-1 monoclonal antibodies in the treatment of HCC and provides antibody selection for the development of novel PD-1 mAb with blocking activity.

Novel Prognostic Model Based on Immune Signature for Head and Neck Squamous Cell Carcinoma

Background

Deciphering the immune characteristics within tumors and identifying the immune signals related to the prognostic factor are helpful for the treatment and management of tumor patients. However, systematic analysis of immune signatures in head and neck squamous cell carcinoma (HNSCC) remains largely unstudied.

Methods

A total of 718 immune-related genes were extracted from RNA sequencing data from 519 HNSCC patients in the TCGA database, and survival analysis with integrated bioinformatics analyses was performed to build the final predictive prognosis model.

Results

The 178 survival-associated genes (P < 0.05) participated in important immune functions, including immune cell activation and migration. Multivariate regression analysis using 93 genes (P < 0.01), together with survival-associated clinicopathological parameters, identified 35 independent prognostic factors. The most significant 8 independent factors were CD3E, CD40LG, TNFRSF4, CD3G, CD5, ITGA2B, ABCB1, and TNFRSF13b. The final prognostic model achieved outstanding predictive efficiency with the highest AUC of 0.963.

Conclusion

Our prognostic model based on the immune signature could effectively predict the prognosis of HNSCC patients, providing novel predictive biomarkers and potential therapeutic targets for HNSCC patients.

Mogamulizumab in Combination with Durvalumab or Tremelimumab in Patients with Advanced Solid Tumors: A Phase I Study

PURPOSE

The study goal was to determine safety, antitumor activity, and pharmacodynamic profile of mogamulizumab, an anti-C-C chemokine receptor 4 (anti-CCR4) mAb targeting effector regulatory T cells (eTreg), in combination with mAb checkpoint inhibitors durvalumab or tremelimumab.

PATIENTS AND METHODS

This was a multicenter, phase I, dose escalation study, followed by disease-specific cohort expansion (NCT02301130). Mogamulizumab dose escalation proceeded with concurrent dose escalation of durvalumab or tremelimumab in patients with advanced solid tumors. Cohort expansion occurred with mogamulizumab 1 mg/kg plus durvalumab 10 mg/kg or tremelimumab 10 mg/kg in patients with advanced pancreatic cancer.

RESULTS

Forty patients were enrolled during dose escalation, followed by 24 patients during dose expansion. No dose-limiting toxicities occurred during dose escalation. No new or unexpected toxicities were seen. Tolerability, the primary endpoint, was acceptable utilizing mogamulizumab 1 mg/kg plus durvalumab or tremelimumab 10 mg/kg in the combined dose escalation and dose expansion cohorts (each n = 19). At these doses, the objective response rate was 5.3% (95% confidence interval, 0.1%-26.0%; one partial response) with each combination treatment. At all doses, mogamulizumab treatment led to almost complete depletion of peripheral eTregs, as well as reduction of intratumoral Tregs in the majority of patients. There was no clear correlation of clinical response with peripheral or intratumoral reduction in CCR4⁺ eTregs or with baseline degree of CCR4⁺ expression.

CONCLUSIONS

Mogamulizumab in combination with durvalumab or tremelimumab did not result in potent antitumor efficacy in patients with advanced solid tumors. Tolerability of mogamulizumab 1 mg/kg combined with durvalumab or tremelimumab 10 mg/kg was acceptable.

Pulmonary Administration: Strengthening the Value of Therapeutic Proximity

In recent years inhaled systems have shown momentum as patient-personalized therapies emerge. A significant improvement in terms of therapeutic efficacy and/or reduction adverse systemic effects is anticipated from their use owing these systems regional accumulation. Nevertheless, whatever safety and efficacy evidence required for inhaled formulations regulatory approval, it still poses an additional hurdle to gaining market access. In contrast with the formal intravenous medicines approval, the narrower adoption of pulmonary administration might rely on discrepancies in pre-clinical and clinical data provided by the marketing authorization holder to the regulatory authorities. Evidences of a diverse and inconsistent regulatory framework led to concerns over toxicity issues and respiratory safety. However, an overall trend to support general concepts of good practices exists. Current regulatory guidelines that supports PK/PD (pharmacokinetics/pharmacodynamic) assessment seeks attention threatening those inhaled formulations set to be approved in the coming years. A more complex scenario arises from the attempt of implementing nanomedicines for pulmonary administration. Cutting-edge image techniques could play a key role in supporting diverse stages of clinical development facilitating this pharmaceutics take off and speed to patients. The ongoing challenge in adapting conventional regulatory frameworks has proven to be tremendously difficult in an environment where market entry relies on multiple collections of evidence. This paper intention is to remind us that an acceptable pre-clinical toxicological program could emerge from, but not only, an accurate and robust data imaging collection. It is our conviction that if implemented, inhaled nanomedicines might have impact in multiple severe conditions, such as lung cancer, by fulfilling the opportunity for developing tailored treatments while solving dose-related toxicity issues; the most limiting threat in conventional lung cancer clinical management.

Radiomics predicts survival of patients with advanced non-small cell lung cancer undergoing PD-1 blockade using Nivolumab

Immune checkpoint blockade is an emerging anticancer strategy, and Nivolumab is a human mAb to PD-1 that is used in the treatment of a number of different malignancies, including non-small cell lung cancer (NSCLC), kidney cancer, urothelial carcinoma and melanoma. Although the use of Nivolumab prolongs survival in a number of patients, this treatment is hampered by high cost. Therefore, the identification of predictive markers of response to treatment in patients is required. In this context, PD-1/PDL1 blockade antitumor effects occur through the reactivation of a pre-existing immune response, and the efficacy of these effects is strictly associated with the presence of necrosis, hypoxia and inflammation at the tumour sites. It has been indicated that these events can be evaluated by specific assessments using a computed tomography (CT) texture analysis (TA) or radiomics. Therefore, a retrospective study was performed, which aimed to evaluate the potential use of this analysis in the identification of patients with NSCLC who may benefit from Nivolumab treatment. A retrospective analysis was performed of 59 patients with metastatic NSCLC who received Nivolumab treatment between January 2015 and July 2017 at Siena University Hospital (35 patients, training dataset), Catanzaro University Hospital and Reggio Calabria Grand Metropolitan Hospital, Italy (24 patients, validation dataset). Pre- and post-contrast CT sequences were used to contour the gross tumour volume (GTV) of the target lesions prior to Nivolumab treatment. The impact of variations on contouring was analysed using two delineations, which were performed on each patient, and the TA parameters were tested for reliability using the Intraclass Coefficient Correlation method (ICC). All analyses for the current study were performed using LifeX Software^©. Imaging, clinical and pathological parameters were correlated with progression free survival and overall survival (OS) using Kaplan Meier analysis. An external validation testing was performed for the TA Score using the validation dataset. A total of 59 patients were included in the analysis of the present study. The reliability ICC analysis of 14 TA parameters indicated a highly reproducibility (ICC >0.70, single measure) in 12 (85%) pre- contrast and 13 (93%) post-contrast exams. A specific cut-off was detected for each of the following parameters: volume (score 1 >36 ml), histogram entropy (score 1 > 1.30), compacity (score 1 <3), gray level co-occurrence matrix (GLCM)-entropy (score 1 >1.80), GLCM-Dissimilarity (score 1 >5) and GLCM-Correlation (score 1<0.54). The global texture score allowed the classification of two subgroups of Low (Score 0-1; 36 patients; 61%) and High Risk patients (Score >1; 23 patients; 39%) that respectively, showed a median OS of 26 (mean +/- SD: 18 +/- 1.98 months; 95% CI 14-21 months) and 5 months (mean +/- SD: 6 +/- 0.99 months; 95% CI: 4-8 months; P=0.002). The current study indicated that TA parameters can identify patients that will benefit from PD-1 blockage by defining the radiological settings that are potentially suggestive of an active immune response. These results require further confirmation in prospective trials.

PLAC8 overexpression correlates with PD-L1 upregulation and acquired resistance to chemotherapies in gallbladder carcinoma

Gallbladder carcinoma (GBC) is always diagnosed at an advanced stage, and patients often miss the opportunity for surgery. Gemcitabine (GEM) and platinum-based drugs, including oxaliplatin (OXA), are mainstays of chemotherapy. However, drug resistance causes treatment failure. Hence, salvage mechanisms are critical to improve outcomes. This study revealed the positive correlation between placenta-specific protein 8 (PLAC8) overexpression and PD-L1 overexpression in GBC. Given the roles of PLAC8 and PD-L1 in chemotherapy resistance, GEM-resistant and OXA-resistant cell lines (SGC966GR and SGC966OR, respectively) were established to test whether and how PLAC8 and PD-L1 function in chemotherapy resistance. Drug-insensitive SGC966GR and SGC966OR cells upregulated MRP and MDR1 and had high expression of PLAC8. PLAC8 blockade using siRNA reversed chemotherapy resistance and downregulated MRP and MDR1 in SGC966GR and SGC966OR cells, suggesting that PLAC8 mediates chemotherapy resistance in GBC. Consistent with the increased mRNA levels of PD-L1 after the acquisition of resistance, PLAC8 knockdown reduced PD-L1 mRNA expression in SGC966GR and SGC966OR cells. In conclusion, PLAC8 overexpression in GBC patients positively correlated with PD-L1 expression. PLAC8 conferred resistance to GEM and OXA by upregulating PD-L1 expression, and PLAC8 or PD-L1 blockade may have potential for overcoming chemotherapy resistance, providing therapeutic options for chemotherapy-refractory GBC patients.

Total HLA Class I Antigen Loss with the Downregulation of Antigen-Processing Machinery Components in Two Newly Established Sarcomatoid Hepatocellular Carcinoma Cell Lines

Limited information is currently available concerning HLA class I antigen abnormalities in sarcomatoid hepatocellular carcinoma (sHCC). Here, we have analyzed the growth characteristics and HLA class I antigen status of four sHCC cell lines (sHCC29, sHCC63, sHCC74, and SAR-HCV); the first three were newly established in this study. Among the four, sHCC29 showed the highest growth rate in vitro and tumorigenicity in NOD-SCID mice. Unlike sHCC74 and SAR-HCV, both sHCC29 and sHCC63 had no detectable surface HLA class I antigen expression, alongside undetected intracellular β₂-microglobulin (β₂m) and marked HLA class I heavy chain and selective antigen-processing machinery (APM) component downregulation. The loss of β₂m in sHCC29 and sHCC63 was caused by a >49 kb deletion across the B2M locus, while their downregulation of APM components was transcriptional, reversible by IFN-γ only in several components. β₂m was also undetected in the primary HCC lesions of the patients involved, indicating its in vivo relevance. We report for the first time HLA class I antigen loss with underlying B2M gene deficiency and APM defects in 50% (2 of 4) of the sHCC cell lines tested. These findings may have implications for a proper design of T cell immunotherapy for the treatment of sHCC patients.

Prognostic Impact of Tumor Cell Programmed Death Ligand 1 Expression and Immune Cell Infiltration in NSCLC

INTRODUCTION

Infiltration of T and B/plasma cells has been linked to NSCLC prognosis, but this has not been thoroughly investigated in relation to the expression of programmed death ligand 1 (PD-L1). Here, we determine the association of lymphocytes and PD-L1 with overall survival (OS) in two retrospective cohorts of operated NSCLC patients who were not treated with checkpoint inhibitors targeting the programmed death 1/PD-L1 axis. Moreover, we evaluate how PD-L1 positivity and clinicopathologic factors affect the prognostic association of lymphocytes.

METHODS

Cluster of differentiation (CD) 3 (CD3)-, CD8-, CD4-, forkhead box P3 (FOXP3)-, CD20-, CD79A-, and immunoglobulin kappa constant (IGKC)-positive immune cells, and tumor PD-L1 positivity, were determined by immunohistochemistry on tissue microarrays (n = 705). Affymetrix data was analyzed for a patient subset, and supplemented with publicly available transcriptomics data (N = 1724). Associations with OS were assessed by Kaplan-Meier plots and uni- and multivariate Cox regression.

RESULTS

Higher levels of T and B plasma cells were associated with longer OS (p = 0.004 and p < 0.001, for CD8 and IGKC, respectively). Highly proliferative tumors with few lymphocytes had the worst outcome. No association of PD-L1 positivity with OS was observed in a nonstratified patient population; however, a significant association with shorter OS was observed in never-smokers (p = 0.009 and p = 0.002, 5% and 50% cutoff). Lymphocyte infiltration was not associated with OS in PD-L1-positive tumors (50% cutoff). The prognostic association of lymphocyte infiltration also depended on the patients' smoking history and histologic subtype.

CONCLUSIONS

Proliferation, PD-L1 status, smoking history, and histology should be considered if lymphocyte infiltration is to be used as a prognostic biomarker.

[IoNESCO trial: Immune neoajuvant therapy in early stage non-small cell lung cancer]

BACKGROUND

Programmed cell death-ligand 1 (PD-L1) is a checkpoint receptor that facilitates immune evasion by tumor cells, through interaction with programmed cell death-1 (PD-1), a receptor expressed by T-cells. Durvalumab is an anti-PD-L1 monoclonal antibody that blocks PD-L1 interaction with PD-1 on T-cells, countering the tumor's immune-evading tactics. Phase I/II studies demonstrated durable responses and manageable tolerability in heavily pre-treated patients with non-small cell lung cancer (NSCLC).

METHODS

This phase II study is designed to administrate three durvalumab IV infusions (10mg/kg at day 1, 15, 29) before surgery, to patients with pathologically confirmed NSCLC, clinical stage IB (>4cm) or stage II, ≥18 years of age, WHO performans status 0-1, without selection on PD-L1 expression. Preoperative chemotherapy and radiation therapy are not permitted. The primary objective is feasibility of complete surgical resection. Major pathological response on surgical tissue, defined as 10% or less remaining tumor cells, will be a secondary objective. Additional secondary objectives include tolerance, adverse effects, delay between start of treatment and surgery, response rate (RECIST 1.1), metabolic response rate, postoperative adverse events, disease-free survival and overall survival. A rate of complete resection<85% (P0) is considered unacceptable. P1 hypothesis is of 95%, and with a study power of 90% and an alpha risk of 5% (two-steps Fleming's procedure), 81 patients are required.

EXPECTED RESULTS

To establish whether neoadjuvant immunotherapy is feasible and could improve the survival of patients with early-stage NSCLC.

Expression and clinical significance of PD‑1 in hepatocellular carcinoma tissues detected by a novel mouse anti-human PD‑1 monoclonal antibody

Hepatocellular carcinoma (HCC) is one of the most common malignancies and causes of death worldwide. Research investigating novel therapeutic strategies for the treatment of HCC is urgently required. Monoclonal antibodies (mAbs) that target the programmed cell death‑1 (PD‑1/PDCD1)/programmed death-ligand 1 (PD-L1) immune checkpoint have demonstrated substantial clinical benefit for a variety of solid tumors; however, these mAbs have not been well studied in HCC. In the present study, Sp2/0-Ag14 myeloma cells and spleen cells derived from BALB/c mice immunized with the recombinant human PD‑1/PDCD1 protein were fused for the production of novel antibodies. The 9E11 mAb, which exhibited the highest specificity for PD‑1 in HCC tissues in western blot and immunohistochemical staining analyses, was used to investigate the clinical significance of PD‑1 expression in HCC tissues from 77 cases, which were collected and examined histologically. Overexpression of PD‑1 was identified in peritumoral tissues, primarily in the liver portal region. Importantly, by analyzing the clinical data from 77 HCC patients, the expression of PD‑1 was observed to be significantly correlated with larger tumor size (>5 cm) and poorly differentiated tumors. In addition, PD‑1 expression was moderately correlated with venous thrombosis, but not correlated with patient sex or age, liver cirrhosis, hepatitis B, tumor, node and metastasis (TNM) stage or tumor location. The results of the present study suggest that high-level PD‑1 expression may be an important factor associated with the immune checkpoint pathway in HCC. The results suggest that PD‑1 serves an important role in tumor immune evasion and may be a valuable immunodiagnostic marker. In addition, PD‑1 may serve as a therapeutic target for patients presenting with poorly differentiated HCC, thus indicating the potential application of a PD‑1 inhibitor for the treatment of HCC patients.

Correlation of Neutrophil to Lymphocyte Ratio and Absolute Neutrophil Count With Outcomes With PD-1 Axis Inhibitors in Patients With Advanced Non-Small-Cell Lung Cancer

INTRODUCTION

Programmed death-1 (PD-1) axis inhibitors have become standard therapy in advanced non-small-cell lung cancer (NSCLC). Response might be delayed and pseudo-progression occasionally occurs in patients who eventually benefit from treatment. Additional markers beyond programmed death ligand 1 (PD-L1) expression are needed to assist in patient selection, response evaluation, and treatment decisions.

MATERIALS AND METHODS

The relationship between prospectively collected clinical outcomes (response, disease control rate [DCR], treatment duration, overall survival) and hematologic parameters (neutrophil to lymphocyte ratio [NLR], absolute neutrophil count [ANC], and platelet to lymphocyte ratio [PLR]) was explored retrospectively in advanced NSCLC patients treated with PD-1 axis inhibitors at a major cancer center from May 2013 to August 2016. Hematologic parameters at baseline and during treatment (week 2 or 3 and week 8) were included.

RESULTS

Of 88 patients treated with PD-1 axis inhibitors, 22 (25%) experienced partial response. Baseline NLR ≤4 was associated with superior DCR (74% vs. 50%; P = .025), treatment duration (P = .037), time to progression (P = .053), and overall survival (P = .019), with no differential association according to PD-L1 tumor expression. Lower NLR and ANC during treatment were also associated with response to treatment (P = .025 and P = .017, respectively), and treatment duration (P = .036 and P = .008). No association was found between baseline PLR and DCR, response, treatment duration, nor overall survival.

CONCLUSION

Baseline NLR ≤4 and lower NLR and ANC during treatment might correlate with disease control and treatment response and should be explored further as potential predictors of treatment benefit in larger studies.

Is there a room for immune checkpoint inhibitors in early stage non-small cell lung cancer?

Early non-small cell lung cancer (NSCLC) represents 16% of all new NSCLC at diagnosis with a 5-year survival rate of about 60%. Surgical intervention and adjuvant platinum-based chemotherapy represent the cornerstone treatments, but no significant advances have been achieved since several decades in term of relapse rate reduction or survival improvement. Immunotherapy represents an appealing strategy considering the acceptable toxicity profile but, despite the awesome changing recently introduced in the locally advanced and metastatic setting, its role in early NSCLC is not clear yet. In the past few years, two strategies have been investigated to improve the early NSCLC outcomes eliciting the anti-tumour immune response: tumour vaccines and adoptive cellular therapies. However, none of them provided convincing results. Preclinical and clinical data supported the prognostic role of immune checkpoints in resected NSCLC even if they did not show a clear predictive value for adjuvant treatment. However, some preliminary data about safety and efficacy of neo-adjuvant immune checkpoint inhibitors encourage further investigation of their potential role as monotherapy or as part of a multimodal strategy. Then, even if no significant progress has been done in early NSCLC treatment until today, checkpoint inhibitors can open the door to a new strategy in this setting.

Immunotherapy in the Asiatic population: any differences from Caucasian population?

As "Immunotherapy age" is coming, immune checkpoint inhibitors (CPI) therapies have shown favorable clinical benefits and low toxicity profiles in patients with advanced non-small cell lung cancer (NSCLC). While it is a pity that there is a little clear clinical trials evidence about immunotherapy among Asian population. Moreover, since there is an ethnic difference for targeted therapy, what about immunotherapy? Which factors may associate with ethnic differences from Caucasian population to Asiatic population? In this review, we supposed that the characteristics of the much higher proportion of EGFR mutation, hepatitis B virus infection and unexpected immune-related toxicity among Asian patients should be considered.

Addressing the elephant in the room, therapeutic resistance in non-small cell lung cancer, with epigenetic therapies

Like Chinese boxes nesting inside each other, the classification of non-small cell lung cancer (NSCLC) is subdivided into smaller and smaller subtypes on the basis of histological and molecular attributes. The latter characterizes NSCLC by its molecular alterations and the identification of inhibitors that target these cancer-specific "driver" mutations. Despite the initial promise of precision-guided therapies to inhibit a finer and finer array of molecular subcategories, despite even the curative potential of immunotherapeutic checkpoint blockade, in particular, casualties still abound and true clinical success stories are few and far between; the ever-present, if sometimes unmentioned, "elephant in the room", is the acquisition of resistance, which, sooner or later, rears its ugly head to undermine treatment success and shorten survival. Emerging data suggests that epigenetic therapies are able to reprogram the aberrant tumor-associated epigenome and 'tame the beast of resistance', thereby prolonging survival. This article reviews the role of epigenetic dysregulation in NSCLC, explores PFS2 as a possible surrogate endpoint, briefly mentions possible biomarkers and highlights combinatorial treatment epigenetic strategies to "prime" tumors and reverse resistance.

Anti-PD-1/PD-L1 antibodies versus docetaxel in patients with previously treated non-small-cell lung cancer

Anti-PD-1/PD-L1 antibodies have been proved one of the most promising treatments against non-small cell lung cancer (NSCLC); however, whether anti-PD-1/PD-L1 antibodies can provide added benefits for pretreated patients with advanced NSCLC and which patients are most likely to benefit from anti-PD-1/PD-L1 therapy remain controversial. This meta-analysis evaluated the efficacy and safety between anti-PD-1/PD-L1 antibodies and docetaxel in previously treated, advanced NSCLC. PubMed, EMBASE and Cochrane library databases were systematically searched for eligible studies. Five studies with a total of 3,025 patients were included. Our results showed that, for all patients, anti-PD-1/PD-L1 therapy prolonged overall survival (OS) (hazard ratio [HR] = 0.69; 95% CI, 0.63-0.75) and progression-free survival (PFS) (HR = 0.87; 95% CI, 0.80-0.94). For patients with PD-L1 expression ≥1%, anti-PD-1/PD-L1 therapy had higher objective response rates. In subgroup analysis according to the tumor PD-L1 expression level, anti-PD-1/PD-L1 therapy was associated with longer OS and PFS in patients with high PD-L1 expression (≥1%, ≥5%, ≥10% and ≥50%), but not in those with low expressions. In subgroup analysis of patients' characteristics, anti-PD-1/PD-L1 antibodies showed OS benefits across most prespecified subgroups, except for patients with EGFR mutation-positive and never smokers. For patients with EGFR mutation, anti-PD-1/PD-L1 therapy was an unfavorable factor of PFS. The grade 3 or 4 adverse events rates of anti-PD-1/PD-L1 treatment were significantly lower than that of docetaxel. Our results suggest that anti-PD-1/PD-L1 therapy significantly improves survival compared with docetaxel in patients with previously treated, PD-L1-positive, advanced NSCLC, and has a distinct safety profile from chemotherapy.

Anti-cancer activity of dose-fractioned mPE +/- bevacizumab regimen is paralleled by immune-modulation in advanced squamous NSLC patients

Background

Results from the BEVA2007 trial, suggest that the metronomic chemotherapy regimen with dose-fractioned cisplatin and oral etoposide (mPE) +/- bevacizumab, a monoclonal antibody to the vascular endothelial growth factor (VEGF), shows anti-angiogenic and immunological effects and is a safe and active treatment for metastatic non-small cell lung cancer (mNSCLC) patients. We carried out a retrospective analysis aimed to evaluate the antitumor effects of this treatment in a subset of patients with squamous histology.

Methods

Retrospective analysis was carried out in a subset of 31 patients with squamous histology enrolled in the study between September 2007 and September 2015. All of the patients received chemotherapy with cisplatin (30 mg/sqm, days 1-3q21) and oral etoposide (50 mg, days 1-15q21) (mPE) and 14 of them also received bevacizumab 5 mg/kg on the day 3q21 (mPEBev regimen).

Results

This treatment showed a disease control rate of 71% with a mean progression free survival (PFS) and overall survival (OS) of 13.6 and 17 months respectively. After 4 treatment courses, 6 patients showing a remarkable tumor shrinkage, underwent to radical surgery, attaining a significant advantage in term of survival (P=0.048). Kaplan-Meier and log-rank test identified the longest survival in patients presenting low baseline levels in neutrophil-to-lymphocyte ratio (NLR) (P=0.05), interleukin (IL) 17A (P=0.036), regulatory-T-cells (T_regs) (P=0.020), and activated CD83+ dendritic cells (DCs) (P=0.03).

Conclusions

These results suggest that the mPE +/- bevacizumab regimen is feasible and should be tested in comparative trials in advanced squamous-NSCLC (sqNSCLC). Moreover, its immune-biological effects strongly suggest the investigation in sequential combinations with immune check-point inhibitors.

Radiotherapy prolongs the survival of advanced non-small-cell lung cancer patients undergone to an immune-modulating treatment with dose-fractioned cisplatin and metronomic etoposide and bevacizumab (mPEBev)

Radiotherapy (RT), together with a direct cytolytic effect on tumor tissue, also elicits systemic immunological events, which sometimes result in the regression of distant metastases (abscopal effect). We have shown the safety and anti-tumor activity of a novel metronomic chemotherapy (mCH) regimen with dose-fractioned cisplatin, oral etoposide and bevacizumab, a mAb against the vasculo-endothelial-growth-factor (mPEBev regimen), in metastatic non-small-cell-lung cancer (mNSCLC). This regimen, designed on the results of translational studies, showed immune-modulating effects that could trigger and empower the immunological effects associated with tumor irradiation. In order to assess this, we carried out a retrospective analysis in a subset of 69 consecutive patients who received the mPEBev regimen within the BEVA2007 trial. Forty-five of these patients, also received palliative RT of one or more metastatic sites. Statistical analysis (a Log-rank test) revealed a much longer median survival in the group of patients who received RT [mCH vs mCH + RT: 12.1 +/-2.5 (95%CI 3.35-8.6) vs 22.12 +/-4.3 (95%CI 11.9-26.087) months; P=0.015] with no difference in progression-free survival. In particular, their survival correlated with the mPEBev regimen ability to induce the percentage of activated dendritic cells (DCs) (CD3-CD11b+CD15-CD83+CD80+) [Fold to baseline value (FBV) ≤1 vs >1: 4+/-5.389 (95%CI,0- 14.56) vs 56+/-23.05 (95%CI,10.8-101.2) months; P:0.049)] and central-memory- T-cells (CD3+CD8+CD45RA-CCR7+) [FBV ≤ 1 vs >1: 8+/-5.96 (95%CI,0-19.68) vs 31+/-12.3 (95%CI,6.94-55.1) months; P:0.045]. These results suggest that tumor irradiation may prolong the survival of NSCLC patients undergone mPEBev regimen presumably by eliciting an immune-mediated effect and provide the rationale for further perspective clinical studies.

An unbiased in vivo functional genomics screening approach in mice identifies novel tumor cell-based regulators of immune rejection

The clinical successes of immune checkpoint therapies for cancer make it important to identify mechanisms of resistance to anti-tumor immune responses. Numerous resistance mechanisms have been identified employing studies of single genes or pathways, thereby parsing the tumor microenvironment complexity into tractable pieces. However, this limits the potential for novel gene discovery to in vivo immune attack. To address this challenge, we developed an unbiased in vivo genome-wide RNAi screening platform that leverages host immune selection in strains of immune-competent and immunodeficient mice to select for tumor cell-based genes that regulate in vivo sensitivity to immune attack. Utilizing this approach in a syngeneic triple-negative breast cancer (TNBC) model, we identified 709 genes that selectively regulated adaptive anti-tumor immunity and focused on five genes (CD47, TGFβ1, Sgpl1, Tex9 and Pex14) with the greatest impact. We validated the mechanisms that underlie the immune-related effects of expression of these genes in different TNBC lines, as well as tandem synergistic interactions. Furthermore, we demonstrate the impact of different genes with previously unknown immune functions (Tex9 and Pex14) on anti-tumor immunity. Thus, this innovative approach has utility in identifying unknown tumor-specific regulators of immune recognition in multiple settings to reveal novel targets for future immunotherapies.

Understanding the checkpoint blockade in lung cancer immunotherapy

Immunotherapies have changed the treatment strategy of some types of tumor including melanoma and, more recently, non-small-cell lung cancer (NSCLC). Immune checkpoints are crucial for the maintenance of self-tolerance and it is known that some tumors use checkpoint systems to evade antitumor immune response. The treatment of advanced NSCLC by immune-checkpoint blockade targeting the programmed cell death protein-1 (PD1/PDL1) and cytotoxic T-lymphocyte antigen 4 (CTLA4) pathways has led to significant clinical benefit either as monotherapy or in combination therapy. Moreover, checkpoint receptors such as lymphocyte activation gene 3 protein (LAG3), T-cell immunoglobulin mucin domain 3 (TIM3) and killer immunoglobulin-like receptors (KIRs) are also being investigated as potential immunotherapeutic targets. This review focuses on the mechanisms of action of the main checkpoint inhibitors in lung cancer and presents the most relevant results from preclinical and clinical studies on immune-based treatments.

Role of the Immune Response in Disease Progression and Therapy in Multiple Myeloma

Multiple myeloma (MM) is a hematologic cancer derived from malignant plasma cells within the bone marrow. Unlike most solid tumors, which originate from epithelial cells, the myeloma tumor is a plasma cell derived from the lymphoid cell lineage originating from a post-germinal B-cell. As such, the MM plasma cell represents an integral component of the immune system in terms of both antibody production and antigen presentation, albeit not efficiently. This fundamental difference has significant implications when one considers the implications of immunotherapy. In the case of lymphoid malignancies such as myeloma, immune-based strategies must take into consideration this important difference, potentially necessitating immunotherapy targeted toward MM to be altered from that targeted at solid tumors. Typically, the immune system "surveys" cells within our body and is able to recognize and attack cancerous cells that may arise. However, some cancer cells are able to evade immune surveillance and continue to flourish, causing disease. The major mechanism leading to an effective tumor-specific response is one that enables effective antigen processing and presentation with subsequent T-cell activation, expansion, and effective trafficking to the tumor site. Plasma cells employ several mechanisms to escape immune surveillance which include altered interactions with T-cells, DCs, bone marrow stromal cells (BMSC's), and natural killer cells (NK Cells) that can be mediated by immunosuppressive cells such as and myeloid-derived suppressor cells (MDSC's) and cytokines such as IL-10, TGFβ, and IL-6 as well as down-regulation of the antigen processing machinery. Many therapies have been developed to reestablish a functional immune system in MM patients. These include adoptive T-cell therapies to deliver more tumor-specific T-cells, vaccines to increase the tumor-specific precursor frequency of the endogenous T-cell population, immunomodulatory agents (IMiDs) such as thalidomide and lenalidomide to enhance global endogenous immunity, immunostimulatory cytokines, and antibodies to specifically target tumor-specific cell-surface proteins or cytokines. This review will dissect these various approaches currently being explored in MM as well as highlight some future directions for myeloma-specific immune-based strategies.

Current studies of immunotherapy in head and neck cancer

BACKGROUND

Recently, enormous progress in cancer therapy has been achieved by the use of immune checkpoint inhibitors. Activating the body's own immune system has added a novel and powerful therapeutic option for the treatment of melanoma and lung cancer. Furthermore, the potential use of immunotherapy is being extensively explored also in other malignancies.

OBJECTIVE OF REVIEW

This review summarises current clinical studies using immune checkpoint modulators for the treatment of head and neck cancer (HNSCC).

TYPE OF REVIEW

Systematic review.

SEARCH STRATEGY

A PubMed search from 2010 onwards was performed for the use of immune checkpoint inhibitors in clinical trials of HNSCC. An equivalent search was performed at clinicaltrials.gov. Additionally, the abstracts from the annual meetings of the ASCO, ESMO and AACR were screened.

RESULTS

A total of 45 relevant studies using immune checkpoint inhibitors in HNSCC were identified. In the majority of these studies, antagonistic antibodies targeting the immune checkpoint receptors PD-1 are used either solely or combined, mostly with other immunomodulatory antibodies, such as inhibitors of CTLA-4. Most studies are still recruiting patients (26/45). In the primary setting, we identified 16 studies using checkpoint inhibition as neoadjuvant/adjuvant modality for treatment with curative intent. The response rate upon treatment with PD-1 antagonists in relation to the PD-L1 status is being investigated in 12 trials. Novel immune checkpoint modulators combined with the inhibition of the PD-1/PD-L1 axis or CTLA-4 have been set up in six trials. So far, only four studies that use immune checkpoint inhibition in HNSCC have presented results and all of these explored the inhibition of the PD-1/PD-L1 axis. The studies demonstrated overall response rates (ORR) in the range of 20%. These preliminary data suggest that a PD-L1 expression ≥1% is associated with a higher response rate compared to a PD-L1 expression ≤1%. The anti-PD-1-antibody pembrolizumab extended the duration of response in recurrent and/or metastatic (R/M) HNSCC (by approximately 53 weeks) in a phase Ib study. Therefore, pembrolizumab was granted accelerated approval for the treatment of platinum refractory R/M HNSCC by the FDA.

CONCLUSION

Numerous clinical trials are addressing the suitability and efficacy of immune checkpoint modulators in HNSCC with the predominant targets being the established immune checkpoint receptors PD-1/PD-L1 and CTLA-4. Recently, presented results have shown a survival benefit, a favourable safety profile and an extended duration of response in favour of using immune checkpoint modulation in R/M HNSCC.

Immune Checkpoint Inhibitors for Patients With Advanced Non-Small-Cell Lung Cancer: A Systematic Review

Second-line treatment options are limited for patients with advanced non-small-cell lung cancer (NSCLC). Standard therapy includes the cytotoxic agents docetaxel and pemetrexed, and the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors erlotinib and gefitinib. Immune checkpoint inhibitors are a new class of treatment that have shown durable overall radiologic response rates and have been well tolerated. The objective of this systematic review was to investigate the efficacy of immune checkpoint inhibitors compared with other chemotherapies in patients with advanced NSCLC. Medline, Embase, and PubMed were searched for randomized controlled trials comparing treatment with immune checkpoint inhibitors against treatment with chemotherapy in patients with stage IIIB or IV NSCLC. Nine randomized controlled trials with 15 publications were included. A significant overall survival benefit of second-line nivolumab (nonsquamous: hazard ratio [HR] = 0.72, 95% confidence interval [CI], 0.60-0.77; P < .001; squamous: HR = 0.59, 95% CI, 0.44-0.79; P < .001) or second-line atezolizumab (HR = 0.73, 95% CI, 0.62-0.87; P = .0003) or second-line pembrolizumab (in patients with programmed cell death ligand 1 [PD-L1]-positive tumors) (pembrolizumab 2 mg/kg HR = 0.71, 95% CI, 0.58-0.88; P = .0008; pembrolizumab 10 mg/kg HR = 0.61, 95% CI, 0.49-0.75; P < .0001) or first-line pembrolizumab (HR = 0.60, 95% CI, 0.41-0.89; P = .005) compared with chemotherapy was found. The adverse effects were mainly higher in the chemotherapy arms. For patients with advanced stage IIIB/IV NSCLC, the improvement in overall survival outweighed the harms and supported the use of first-line pembrolizumab (in patients with ≥ 50% PD-L1-positive tumors) or second-line nivolumab, atezolizumab, or pembrolizumab (in patients with PD-L1-positive tumors).

Neutrophils dominate the immune cell composition in non-small cell lung cancer

The response rate to immune checkpoint inhibitor therapy for non-small-cell lung cancer (NSCLC) is just 20%. To improve this figure, several early phase clinical trials combining novel immunotherapeutics with immune checkpoint blockade have been initiated. Unfortunately, these trials have been designed without a strong foundational knowledge of the immune landscape present in NSCLC. Here, we use a flow cytometry panel capable of measuring 51 immune cell populations to comprehensively identify the immune cell composition and function in NSCLC. The results show that the immune cell composition is fundamentally different in lung adenocarcinoma as compared with lung squamous cell carcinoma, and that neutrophils are the most prevalent immune cell type. Using T-cell receptor-β sequencing and tumour reactivity assays, we predict that tumour reactive T cells are frequently present in NSCLC. These results should help to guide the design of clinical trials and the direction of future research in this area.

Clonal Evolutionary Analysis during HER2 Blockade in HER2-Positive Inflammatory Breast Cancer: A Phase II Open-Label Clinical Trial of Afatinib +/- Vinorelbine

BACKGROUND

Inflammatory breast cancer (IBC) is a rare, aggressive form of breast cancer associated with HER2 amplification, with high risk of metastasis and an estimated median survival of 2.9 y. We performed an open-label, single-arm phase II clinical trial (ClinicalTrials.gov NCT01325428) to investigate the efficacy and safety of afatinib, an irreversible ErbB family inhibitor, alone and in combination with vinorelbine in patients with HER2-positive IBC. This trial included prospectively planned exome analysis before and after afatinib monotherapy.

METHODS AND FINDINGS

HER2-positive IBC patients received afatinib 40 mg daily until progression, and thereafter afatinib 40 mg daily and intravenous vinorelbine 25 mg/m2 weekly. The primary endpoint was clinical benefit; secondary endpoints were objective response (OR), duration of OR, and progression-free survival (PFS). Of 26 patients treated with afatinib monotherapy, clinical benefit was achieved in 9 patients (35%), 0 of 7 trastuzumab-treated patients and 9 of 19 trastuzumab-naïve patients. Following disease progression, 10 patients received afatinib plus vinorelbine, and clinical benefit was achieved in 2 of 4 trastuzumab-treated and 0 of 6 trastuzumab-naïve patients. All patients had treatment-related adverse events (AEs). Whole-exome sequencing of tumour biopsies taken before treatment and following disease progression on afatinib monotherapy was performed to assess the mutational landscape of IBC and evolutionary trajectories during therapy. Compared to a cohort of The Cancer Genome Atlas (TCGA) patients with HER2-positive non-IBC, HER2-positive IBC patients had significantly higher mutational and neoantigenic burden, more frequent gain-of-function TP53 mutations and a recurrent 11q13.5 amplification overlapping PAK1. Planned exploratory analysis revealed that trastuzumab-naïve patients with tumours harbouring somatic activation of PI3K/Akt signalling had significantly shorter PFS compared to those without (p = 0.03). High genomic concordance between biopsies taken before and following afatinib resistance was observed with stable clonal structures in non-responding tumours, and evidence of branched evolution in 8 of 9 tumours analysed. Recruitment to the trial was terminated early following the LUX-Breast 1 trial, which showed that afatinib combined with vinorelbine had similar PFS and OR rates to trastuzumab plus vinorelbine but shorter overall survival (OS), and was less tolerable. The main limitations of this study are that the results should be interpreted with caution given the relatively small patient cohort and the potential for tumour sampling bias between pre- and post-treatment tumour biopsies.

CONCLUSIONS

Afatinib, with or without vinorelbine, showed activity in trastuzumab-naïve HER2-positive IBC patients in a planned subgroup analysis. HER2-positive IBC is characterized by frequent TP53 gain-of-function mutations and a high mutational burden. The high mutational load associated with HER2-positive IBC suggests a potential role for checkpoint inhibitor therapy in this disease.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01325428.

Immune-modulating effects of bevacizumab in metastatic non-small-cell lung cancer patients

The mPEBev is an anticancer regimen which combines a chemotherapy doublet, based on cisplatin and oral etoposide (mPE), with bevacizumab (mPEBev), a mAb targeting the vasculo-endothelial growth factor (VEGF). In previous studies, this regimen showed powerful anti-angiogenetic effects and significant antitumor activity in metastatic non-small-cell lung cancer (mNSCLC) patients. We also recorded the best benefit in patients exhibiting low-systemic inflammatory profile at baseline. On these bases, we hypothesized that mPEBev antitumor activity could be partially related to bevacizumab-associated immunological effects. For this reason, we performed an immunological monitoring in 59 out of 120 stage IIIb-IV NSCLC patients enrolled in the BEVA2007 phase II trial, who received fractioned cisplatin (30 mg/sqm days 1-3q21) and oral etoposide (50 mg, days 1-15q21) (mPE doublet) ±bevacizumab. In this group of patients, 12 received the mPE doublet alone and 47 the doublet in combination with bevacizumab (5 mg/kg on the day 3q21; mPEBev regimen). Blood cell counts, serum analysis, multiplex cytokine assay and immunocytofluorimetric analysis, performed on baseline and post-treatment on blood samples from these patients, revealed that bevacizumab addition to the doublet decreased levels of pro-angiogenic (VEGF, Angiostatin-1 and Follistatin) and inflammatory cytokines (interferon (IFN)γ, IL4 and IL17), improved in vivo and in vitro cytotoxic T-lymphocytes (CTL) response and promoted dendritic cell activation. These results suggest that the mPEBev regimen improve the micro-environmental conditions for an efficient antigen-specific CTL response, making it a feasible candidate regimen to be assessed in combination with immune-checkpoint inhibitors in NSCLC patients.

Trends and advances in tumor immunology and lung cancer immunotherapy

Among several types of tumor, lung cancer is considered one of the most fatal and still the main cause of cancer-related deaths. Although chemotherapeutic agents can improve survival and quality of life compared with symptomatic treatment, cancers usually still progress after chemotherapy and are often aggravated by serious side effects. In the last few years there has been a growing interest in immunotherapy for lung cancer based on promising preliminary results in achieving meaningful and durable treatments responses with minimal manageable toxicity. This article is divided into two parts, the first part discusses the role of human immune system in controlling and eradicating cancer and the mechanisms of immune response evasion by tumor. The second part reviews the recent progress made in immunotherapy for lung cancer with results from trials evaluating therapeutic vaccines in addition to immune checkpoint blockade, specifically cytotoxic T lymphocyte associated protein 4, programmed death receptor 1 pathway, using monoclonal antibodies.

Small Molecular TRAIL Inducer ONC201 Induces Death in Lung Cancer Cells: A Preclinical Study

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) selectively targets cancer cells. The present preclinical study investigated the anti-cancer efficiency of ONC201, a first-in-class small molecule TRAIL inducer, in lung cancer cells. We showed that ONC201 was cytotoxic and anti-proliferative in both established (A549 and H460 lines) and primary human lung cancer cells. It was yet non-cytotoxic to normal lung epithelial cells. Further, ONC201 induced exogenous apoptosis activation in lung cancer cells, which was evidenced by TRAIL/death receptor-5 (DR5) induction and caspase-8 activation. The caspase-8 inhibitor or TRAIL/DR5 siRNA knockdown alleviated ONC201's cytotoxicity against lung cancer cells. Molecularly, ONC201 in-activated Akt-S6K1 and Erk signalings in lung cancer cells, causing Foxo3a nuclear translocation. For the in vivo studies, intraperitoneal injection of ONC201 at well-tolerated doses significantly inhibited xenografted A549 tumor growth in severe combined immunodeficient (SCID) mice. Further, ONC201 administration induced TRAIL/DR5 expression, yet inactivated Akt-S6K1 and Erk in tumor tissues. These results of the study demonstrates the potent anti-lung cancer activity by ONC201.

Multiparametric profiling of non-small-cell lung cancers reveals distinct immunophenotypes

BACKGROUND. Immune checkpoint blockade improves survival in a subset of patients with non-small-cell lung cancer (NSCLC), but robust biomarkers that predict response to PD-1 pathway inhibitors are lacking. Furthermore, our understanding of the diversity of the NSCLC tumor immune microenvironment remains limited. METHODS. We performed comprehensive flow cytometric immunoprofiling on both tumor and immune cells from 51 NSCLCs and integrated this analysis with clinical and histopathologic characteristics, next-generation sequencing, mRNA expression, and PD-L1 immunohistochemistry (IHC). RESULTS. Cytometric profiling identified an immunologically "hot" cluster with abundant CD8⁺ T cells expressing high levels of PD-1 and TIM-3 and an immunologically "cold" cluster with lower relative abundance of CD8⁺ T cells and expression of inhibitory markers. The "hot" cluster was highly enriched for expression of genes associated with T cell trafficking and cytotoxic function and high PD-L1 expression by IHC. There was no correlation between immunophenotype and KRAS or EGFR mutation, or patient smoking history, but we did observe an enrichment of squamous subtype and tumors with higher mutation burden in the "hot" cluster. Additionally, approximately 20% of cases had high B cell infiltrates with a subset producing IL-10. CONCLUSIONS. Our results support the use of immune-based metrics to study response and resistance to immunotherapy in lung cancer. FUNDING. The Robert A. and Renée E. Belfer Family Foundation, Expect Miracles Foundation, Starr Cancer Consortium, Stand Up to Cancer Foundation, Conquer Cancer Foundation, International Association for the Study of Lung Cancer, National Cancer Institute (R01 CA205150), and the Damon Runyon Cancer Research Foundation.

Trial Watch: Immunotherapy plus radiation therapy for oncological indications

Malignant cells succumbing to some forms of radiation therapy are particularly immunogenic and hence can initiate a therapeutically relevant adaptive immune response. This reflects the intrinsic antigenicity of malignant cells (which often synthesize a high number of potentially reactive neo-antigens) coupled with the ability of radiation therapy to boost the adjuvanticity of cell death as it stimulates the release of endogenous adjuvants from dying cells. Thus, radiation therapy has been intensively investigated for its capacity to improve the therapeutic profile of several anticancer immunotherapies, including (but not limited to) checkpoint blockers, anticancer vaccines, oncolytic viruses, Toll-like receptor (TLR) agonists, cytokines, and several small molecules with immunostimulatory effects. Here, we summarize recent preclinical and clinical advances in this field of investigation.

Macrophages, Inflammation, and Lung Cancer

Lung cancer is the leading cause of cancer mortality worldwide, and at only 18%, it has one of the lowest 5-year survival rates of all malignancies. With its highly complex mutational landscape, treatment strategies against lung cancer have proved largely ineffective. However with the recent success of immunotherapy trials in lung cancer, there is renewed enthusiasm in targeting the immune component of tumors. Macrophages make up the majority of the immune infiltrate in tumors and are a key cell type linking inflammation and cancer. Although the mechanisms through which inflammation promotes cancer are not fully understood, two connected hypotheses have emerged: an intrinsic pathway, driven by genetic alterations that lead to neoplasia and inflammation, and an extrinsic pathway, driven by inflammatory conditions that increase cancer risk. Here, we discuss the contribution of macrophages to these pathways and subsequently their roles in established tumors. We highlight studies investigating the association of macrophages with lung cancer prognosis and discuss emerging therapeutic strategies for targeting macrophages in the tumor microenvironment.

Non-Small-Cell Lung Cancer: Role of the Immune System and Potential for Immunotherapy

As the leading cause of cancer death worldwide, lung cancer continues to impose a major burden on healthcare systems and cause significant challenges for clinicians and patients. Most patients present with advanced disease at the time of diagnosis and have a poor prognosis, with the vast majority surviving less than 5 years. Although new therapies have been introduced in recent years that target molecular disease drivers present in a subset of patients, there is a significant need for treatments able to improve response and extend survival while minimizing effects on quality of life. Recent evidence of clinical efficacy for immunotherapeutic approaches for lung cancer suggests that they will become the next major therapeutic advance for this disease. Non-small-cell lung cancer, which accounts for approximately 85% of lung cancer cases, has historically been considered a nonimmunogenic disease; however, as with several other malignancies, recent data show that much of this lack of immune responsiveness is functional rather than structural (i.e., possible to overcome therapeutically). This review explores the key elements of the immune system involved in non-small-cell lung cancer and briefly examines immunotherapeutic strategies in development to shift the balance of immune activity away from a tumor-induced immune-suppressive state toward an active antitumor immune response.

Immune checkpoint therapy for non-small-cell lung cancer: an update

The role of immunotherapy in treatment of non-small-cell lung cancer (NSCLC) has been gaining interest over the past few years. This has been driven primarily by promising results from trials evaluating antagonist antibodies that target co-inhibitory immune checkpoints expressed on tumor cells and immune cells within the tumor microenvironment. Immune checkpoints exist to dampen or terminate immune activity to guard against autoimmunity and allow for self-tolerance. However, tumors can take advantage of these immune checkpoint pathways to evade destruction. Antibodies that block inhibitory checkpoints, such as anti-CTLA-4, anti-PD1 and anti-PD-L1 antibodies have demonstrated delayed tumor growth and increased survival. Novel therapies are now investigating combining checkpoint inhibitors with chemotherapy, targeted therapy, radiation and vaccines to produce synergistic antitumor activity.

Non–Small Cell Lung Cancer, PD-L1, and the Pathologist

Context

Although most primary cancers of the lung carry a heavy mutational load and will potentially present many “nonself” antigens to the immune system, there are a wide range of possible mechanisms for tumors to avoid so-called immune surveillance. One such mechanism is the adoption of immune checkpoints to inhibit the host immune response. Immune checkpoint inhibitors show great promise in the treatment of advanced non–small cell lung cancer.

Objective

—To discuss the possibility of biomarker selection of patients for these therapies. This is becoming a much debated issue, and the immunohistochemical detection of Programmed Death Ligand 1 (PD-L1), the ligand for the inhibitory Programmed Death receptor 1 (PD-1) checkpoint, is one possible biomarker. Data so far available show some conflicting results, but PD-L1 immunohistochemistry looks likely to be introduced into clinical use for selecting patients for treatment with anti–PD-1 or anti–PD-L1 therapies. Given that there are 4 such drugs rapidly approaching regulatory approval, each with its own independent PD-L1 immunohistochemistry biomarker test, both oncologists and pathologists face some significant challenges.

Data Sources

Peer-reviewed literature and meeting proceedings, especially during the last 12 months, were used.

Conclusions

—The biology of PD-1/PD-L1 is complex, the clinical data for these drugs show considerable variation, the selection performance of the PD-L1 biomarker test is not perfect, and the existence of 4 drug/test combinations adds significantly to the problems faced. This article addresses some of the background to this therapeutic problem and discusses some of the issues ahead.

Immune based therapy for melanoma

A few years ago therapeutic options in advanced melanoma were very limited and the prognosis was somber. Although recent progresses are far from providing a cure for advanced melanoma, yet these have kindled new hopes and searching for a cure does not seem unreasonable. Seven new medicines have been authorized in various regions of the world in the recent past in the therapy of advanced melanoma, over half of them acting by mechanisms involving the immune system of the host. The anti-CTLA-4 (cytotoxic T lymphocyte associated protein-4) ipilimumab has been followed by anti-PD1 (programmed death1) inhibitors, more effective and safer. Very recently, the first oncolytic immunotherapy, talimogene laherparepvec (T-VEC) has been authorized for placing on the market and a variety of combinations of the new therapies are currently being evaluated or considered. Besides, a plethora of other molecules and approaches, especially monoclonal antibodies, are in the preliminary phases of clinical investigation and are likely to bring new benefits for the treatment of this potentially fatal form of cancer.

Cancer stem cells and immunoresistance: clinical implications and solutions

Tumor cells can be contained, but not eliminated, by traditional cancer therapies. A cell minor subpopulation is able to evade attack from therapies and may have cancer stem cell (CSC) characteristics, including self-renewal, multiple differentiation and tumor initiation (tumor initiating cells, or TICs). Thus, CSCs/TICs, aided by the microenvironment, produce more differentiated, metastatic cancer cells which the immune system detects and interacts with. There are three phases to this process: elimination, equilibrium and escape. In the elimination phase the immune system recognizes and destroys most of the tumor cells. Then the latency phase begins, consisting of equilibrium between immunological elimination and tumor cell growth. Finally, a minor attack-resistant subpopulation escapes and forms a clinically detectable tumor mass. Herein we review current knowledge of immunological characterization of CSCs/TICs. Due to the correlation between CTCs/TICs and drug resistance and metastasis, we also comment on the crucial role of key molecules involved in controlling CSCs/TICs properties; such molecules are essential to detect and destroy CSCs/TICs. Monoclonal antibodies, antibody constructs and vaccines have been designed to act against CSCs/TICs, with demonstrated efficacy in human cancer xenografts and some antitumor activity in human clinical studies. Therefore, therapeutic strategies that selectively target CSCs/TICs warrant further investigation. Better understanding of the interaction between CSCs and tumor immunology may help to identify strategies to eradicate the minor subpopulation that escapes conventional therapy attack, thus providing a solution to the problem of drug resistance and metastasis.

Novel cancer antigens for personalized immunotherapies: latest evidence and clinical potential

The clinical success of monoclonal antibody immune checkpoint modulators such as ipilimumab, which targets cytotoxic T lymphocyte-associated antigen 4 (CTLA-4), and the recently approved agents nivolumab and pembrolizumab, which target programmed cell death receptor 1 (PD-1), has stimulated renewed enthusiasm for anticancer immunotherapy, which was heralded by Science as 'Breakthrough of the Year' in 2013. As the potential of cancer immunotherapy has been recognized since the 1890s when William Coley showed that bacterial products could be beneficial in cancer patients, leveraging the immune system in the treatment of cancer is certainly not a new concept; however, earlier attempts to develop effective therapeutic vaccines and antibodies against solid tumors, for example, melanoma, frequently met with failure due in part to self-tolerance and the development of an immunosuppressive tumor microenvironment. Increased knowledge of the mechanisms through which cancer evades the immune system and the identification of tumor-associated antigens (TAAs) and negative immune checkpoint regulators have led to the development of vaccines and monoclonal antibodies targeting specific tumor antigens and immune checkpoints such as CTLA-4 and PD-1. This review first discusses the established targets of currently approved cancer immunotherapies and then focuses on investigational cancer antigens and their clinical potential. Because of the highly heterogeneous nature of tumors, effective anticancer immunotherapy-based treatment regimens will likely require a personalized combination of therapeutic vaccines, antibodies and chemotherapy that fit the specific biology of a patient's disease.

The Microenvironment of Lung Cancer and Therapeutic Implications

The tumor microenvironment (TME) represents a milieu that enables tumor cells to acquire the hallmarks of cancer. The TME is heterogeneous in composition and consists of cellular components, growth factors, proteases, and extracellular matrix. Concerted interactions between genetically altered tumor cells and genetically stable intratumoral stromal cells result in an "activated/reprogramed" stroma that promotes carcinogenesis by contributing to inflammation, immune suppression, therapeutic resistance, and generating premetastatic niches that support the initiation and establishment of distant metastasis. The lungs present a unique milieu in which tumors progress in collusion with the TME, as evidenced by regions of aberrant angiogenesis, acidosis and hypoxia. Inflammation plays an important role in the pathogenesis of lung cancer, and pulmonary disorders in lung cancer patients such as chronic obstructive pulmonary disease (COPD) and emphysema, constitute comorbid conditions and are independent risk factors for lung cancer. The TME also contributes to immune suppression, induces epithelial-to-mesenchymal transition (EMT) and diminishes efficacy of chemotherapies. Thus, the TME has begun to emerge as the "Achilles heel" of the disease, and constitutes an attractive target for anti-cancer therapy. Drugs targeting the components of the TME are making their way into clinical trials. Here, we will focus on recent advances and emerging concepts regarding the intriguing role of the TME in lung cancer progression, and discuss future directions in the context of novel diagnostic and therapeutic opportunities.

Checkpoint inhibitors in Hodgkin's lymphoma

Hodgkin's lymphoma is unusual among cancers in that it consists of a small number of malignant Hodgkin/Reed-Sternberg cells in a sea of immune system cells, including T cells. Most of these T cells are reversibly inactivated in different ways and their reactivation may induce a very strong immune response to cancer cells. One way of reactivation of T cells is with antibodies blocking the CTLA-4 and especially with antibodies directed against PD-1 or the PD-L1 ligand thereby reversing the tumor-induced downregulation of T-cell function and augmenting antitumor immune activity at the priming (CTLA-4) or tissue effector (PD-1) phase. Immune checkpoint inhibitors have been evidenced as an additional treatment option with substantial effectiveness and acceptable toxicity in heavily pretreated patients with Hodgkin's lymphoma. Particularly, PD-1 blockade with nivolumab and pembrolizumab has demonstrated significant single-agent activity in this select population.

Control of PD-L1 Expression by Oncogenic Activation of the AKT-mTOR Pathway in Non-Small Cell Lung Cancer

Alterations in EGFR, KRAS, and ALK are oncogenic drivers in lung cancer, but how oncogenic signaling influences immunity in the tumor microenvironment is just beginning to be understood. Immunosuppression likely contributes to lung cancer, because drugs that inhibit immune checkpoints like PD-1 and PD-L1 have clinical benefit. Here, we show that activation of the AKT-mTOR pathway tightly regulates PD-L1 expression in vitro and in vivo. Both oncogenic and IFNγ-mediated induction of PD-L1 was dependent on mTOR. In human lung adenocarcinomas and squamous cell carcinomas, membranous expression of PD-L1 was significantly associated with mTOR activation. These data suggest that oncogenic activation of the AKT-mTOR pathway promotes immune escape by driving expression of PD-L1, which was confirmed in syngeneic and genetically engineered mouse models of lung cancer where an mTOR inhibitor combined with a PD-1 antibody decreased tumor growth, increased tumor-infiltrating T cells, and decreased regulatory T cells.

T Lymphocyte-Endothelial Interactions: Emerging Understanding of Trafficking and Antigen-Specific Immunity

Antigen-specific immunity requires regulated trafficking of T cells in and out of diverse tissues in order to orchestrate lymphocyte development, immune surveillance, responses, and memory. The endothelium serves as a unique barrier, as well as a sentinel, between the blood and the tissues, and as such it plays an essential locally tuned role in regulating T cell migration and information exchange. While it is well established that chemoattractants and adhesion molecules are major determinants of T cell trafficking, emerging studies have now enumerated a large number of molecular players as well as a range of discrete cellular remodeling activities (e.g., transmigratory cups and invadosome-like protrusions) that participate in directed migration and pathfinding by T cells. In addition to providing trafficking cues, intimate cell-cell interaction between lymphocytes and endothelial cells provide instruction to T cells that influence their activation and differentiation states. Perhaps the most intriguing and underappreciated of these "sentinel" roles is the ability of the endothelium to act as a non-hematopoietic "semiprofessional" antigen-presenting cell. Close contacts between circulating T cells and antigen-presenting endothelium may play unique non-redundant roles in shaping adaptive immune responses within the periphery. A better understanding of the mechanisms directing T cell trafficking and the antigen-presenting role of the endothelium may not only increase our knowledge of the adaptive immune response but also empower the utility of emerging immunomodulatory therapeutics.

Clinical significance of expanded Foxp3⁺ Helios⁻ regulatory T cells in patients with non-small cell lung cancer

The functions of different regulatory T cell (T_reg) types in cancer progression are unclear. Recently, expression of the transcription factor Helios was proposed as a marker for natural (non-induced) T_regs. The present study investigated the clinical significance of Helios expression in patients with non-small cell lung cancer (NSCLC). We enrolled 64 patients with NSCLC, of whom 45 were treated surgically and 19 received chemotherapy because of advanced/recurrent disease. Their peripheral blood mononuclear cells were examined by flow cytometry. From the 45 surgery patients, we matched 9 patients with recurrent disease with 9 stage-matched patients without recurrence (n=18), compared their specimens immunohistochemically for tumor infiltrating lymphocytes (TILs) and analyzed these data against clinicopathological factors. Helios expression in Foxp3⁺ T_regs was 47.5±13.3% in peripheral blood and 18.1±13.4% in tumor specimens. Percentage of Helios⁻ T_regs among CD4⁺ T cells were significantly higher in the cancer patients (2.4%), especially those with stage IA disease (2.6%) than in healthy donors (1.5%; P<0.001). Patients with low levels of Helios expression in T_regs among their TILs had significantly poorer survival (P=0.038). Helios⁻ T_regs may affect immune suppression, even in early stage NSCLC; they could also be a useful prognostic biomarker in patients with NSCLC, and possibly a novel cancer immunotherapy target.

Targeting immune checkpoints: New opportunity for mesothelioma treatment?

Malignant pleural mesothelioma is an aggressive cancer linked to asbestos exposure in most patients. Due to the long latency between exposure and presentation, incidence is expected to further increase in the next decade, despite the ban on asbestos import which occurred at the end of last century in industrialized countries. Platinum-based palliative chemotherapy is the only treatment with proven benefit on outcome, resulting in selected patients in a median overall survival of about 1 year. Therefore, there is room for therapeutic improvement using a new strategy to prolong survival. Dealing with cancer cell induced immunosuppression is a promising approach. Reactivating immune responses that are silenced by immune checkpoints recently gained a lot of interest. Checkpoint blockade has already shown promising preclinical and clinical results in several cancer types and is currently also being investigated in mesothelioma. Here, we discuss the expression patterns and mechanisms of action of CTLA-4 and PD-1 as the two most studied and of TIM-3 and LAG-3 as two interesting upcoming immune checkpoints. Furthermore, we review the clinical results of molecules blocking these immune checkpoints and point out their future opportunities with a special focus on mesothelioma.