Nivolumab and Pembrolizumab for Non–Small Cell Lung Cancer

Checkpoint Blockade in Lung Cancer and Mesothelioma

In the last decade, immunotherapy has emerged as a new treatment modality in cancer. The most success has been achieved with the class of checkpoint inhibitors (CPIs), antibodies that unleash the antitumor immune response. After the success in melanoma, numerous clinical trials are being conducted investigating CPIs in lung cancer and mesothelioma. The programmed death protein (PD) 1-PD ligand 1/2 pathway and cytotoxic T lymphocyte-associated protein 4 are currently the most studied immunotherapeutic targets in these malignancies. In non-small cell lung cancer, anti-PD-1 antibodies have become part of the approved treatment arsenal. In small cell lung cancer and mesothelioma, the efficacy of checkpoint inhibition has not yet been proven. In this Concise Clinical Review, an overview of the landmark clinical trials investigating checkpoint blockade in lung cancer and mesothelioma is provided. Because response rates are around 20% in the majority of clinical trials, there is much room for improvement. Predictive biomarkers are therefore essential to fully develop the potential of CPIs. To increase efficacy, multiple clinical trials investigating the combination of cytotoxic T lymphocyte-associated protein 4 inhibitors and PD-1/PD ligand 1 blockade in lung cancer and mesothelioma are being conducted. Given the potential benefit of immunotherapy, implementation of current and new knowledge in trial designs and interpretation of results is essential for moving forward.

Treatment of elderly patients or patients who are performance status 2 (PS2) with advanced Non-Small Cell Lung Cancer without epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) translocations - Still a daily challenge

Cytotoxic chemotherapy remains the core treatment strategy for patients with advanced non-small cell lung cancer (NSCLC) with tumours that do not have actionable molecular alterations, such as epidermal growth factor receptor (EGFR)-sensitising mutations, anaplastic lymphoma kinase (ALK) translocations or ROS1 translocations. Age and performance status (PS) are two pivotal factors to guide treatment decisions regarding the use of chemotherapy in lung cancer patients. Lung cancer is predominantly a disease of the elderly, with more than two-thirds of patients aged ≥65 years, the current definition of 'elderly'. The prevalence of poor PS, as estimated by patients themselves, can be as high as 50%. Both the elderly and PS2 patients are underrepresented in clinical trials. Therefore, optimising treatment strategy for the subgroup of elderly or PS2 patients with advanced NSCLC remains challenging as a result of a paucity of clinical trial data. The current review focusses on the elderly or PS2 patients without actionable oncogenic drivers and attempts to summarise current available data on recent treatments trials including angiogenesis inhibitors and immune-checkpoint inhibitors.

Radiation alters PD-L1/NKG2D ligand levels in lung cancer cells and leads to immune escape from NK cell cytotoxicity via IL-6-MEK/Erk signaling pathway

We investigated whether radiation influences the susceptibility of non-small cell lung cancer (NSCLC) cells to NK cell mediated cytotoxicity. We found radiation treatment increased expression of programmed cell death ligand 1 (PD-L1), but decreased NK group 2, member D (NKG2D) ligand expressions in A549 and H157 NSCLC cells. Both types of changes would have protected tumor cells from the cytotoxic action of NK cells. Consistently, we detected similar alteration in these molecules in radioresistant A549R26-1 and H157R24-1 subline cells. Higher PD-L1 level was also observed in tumors of A549R26-1 cell-derived xenografts than tumors of parental A549 (A549P) cell-derived xenografts. Accordingly, we found radioresistant cells were more resistant to the cytotoxic action of NK cells than parental cells, and such resistance was decreased when neutralizing antibody (Ab) of PD-L1 was added to the radioresistant cell/NK cell co-cultures. In mechanism studies, we found that IL-6-MEK/Erk signaling contributed most significantly to the up-regulation of PD-L1/down-regulation of NKG2D ligands in radioresistant cells. The addition of the MEK/Erk inhibitor increased the susceptibility of A549R26-1 and H157R24-1 cells to NK-cell cytotoxicity while no significant effect was observed in parental cells. Moreover, we detected enhanced NK-cell cytotoxicity to radioresistant cells when PD-L1 Ab and MEK/Erk inhibitor were added together to co-cultures of tumor/NK cells compared to when PD-L1 Ab was used alone. We suggest that combined use of PD-L1 Ab and MEK/Erk inhibitor may offer better therapeutic benefits than PD-L1 Ab alone to treat NSCLC patients who are receiving radiotherapy or who are at the radioresistant stage.

A Four-Factor Immunoscore System That Predicts Clinical Outcome for Stage II/III Gastric Cancer

The American Joint Committee on Cancer (AJCC) staging system is insufficiently prognostic for operable gastric cancer patients; therefore, complementary factors are under intense investigation. Although the focus is on immune markers, the prognostic impact of a single immune factor is minimal, due to complex antitumor immune responses. A more comprehensive evaluation may engender more accurate predictions. We analyzed immune factors by immunohistochemical staining in two independent cohorts. The association with patients' survival was analyzed by the Kaplan-Meier method. Our immunoscore system was constructed using Cox proportional hazard analysis. PD-L1⁺ immune cells (IC), PD-L1⁺ tumor cells (TC), PD-1^hi, and CD8^More were found among 33.33%, 31.37%, 33.33%, and 49%, respectively, of patients from the discovery cohort, and 41.74%, 17.4%, 38.26%, and 30.43% from the validation cohort. PD-L1⁺ ICs and PD-1^hi ICs correlated with poorer overall survival (OS), but PD-L1⁺ TCs correlated with better OS and clinical outcomes and infiltration of more CD8⁺ T cells. These four factors were independently prognostic after tumor/lymph nodes/metastasis (TNM) stage adjustment. An immunoscore system based on hazard ratios of the four factors further separated gastric cancer patients with similar TNM staging into low-, medium-, or high-risk groups, with significantly different survival. Our prognostic model yielded an area under the receiver operating characteristic curve (AUC) of 0.856 for prediction of mortality at 5 years, superior to that of TNM staging (AUC of 0.676). Thus, this more comprehensive immunoscore system can provide more accurate prognoses and is an essential complement to the AJCC staging system for operable gastric cancer patients. Cancer Immunol Res; 5(7); 524-34. ©2017 AACR.

Treatment advances in small cell lung cancer (SCLC)

Small cell lung cancer (SCLC) is an aggressive tumor characterized by rapid doubling time and high propensity for early development of disseminated disease. Although most patients respond to initial therapy with a platinum doublet, the majority of those with limited stage and virtually all patients with metastatic disease eventually develop tumor progression for which there are limited treatment options. There have been no recent changes in the treatment of SCLC, with platinum plus etoposide and topotecan as the standard first-line and second-line respectively, neither showing survival benefit over the combination of cyclophosphamide, doxorubicin and vincristine, which was developed in the 1970s. More recently, a new understanding of the biology of SCLC has led to the development of novel drugs, of which the most promising are the immune checkpoint inhibitors and the antibody drug conjugate rovalpituzumab tesirine.

Current status of research and treatment for non-small cell lung cancer in never-smoking females

Lung cancer is the leading cause of cancer-related deaths worldwide with over 1 million deaths each year. The overall prognosis of lung cancer patients remains unsatisfactory, with a 5-year overall survival rate of less than 15%. Although most lung cancers are a result of smoking, approximately 25% of lung cancer cases worldwide are not attributable to tobacco use. Notably, more than half of the lung cancer cases in women occur in non-smokers. Among non-small-cell lung cancer (NSCLC) cases, cigarette-smokers have a greater association with squamous cell carcinoma than adenocarcinoma, which is more common in non-smokers. These findings imply that specific molecular and pathological features may associate with lung adenocarcinoma arising in non-smoker female patients. Over the past decade, whole genome sequencing and other '-omics' technologies led to the discovery of pathogenic mutations that drive tumor cell formation. These technological developments may enable tailored patient treatments throughout the course of their disease, potentially leading to improved patient outcomes. Some clinical and laboratory studies have shown success outcomes using epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitors (TKI) in patients with EGFR mutations and ALK rearrangements, respectively. In fact, these 2 mutations are predominantly present in female non-smokers with adenocarcinoma. Immunotherapy has also recently emerged as a major therapeutic modality in NSCLC. In this review, we summarize the current understanding of NSCLC biology and new therapeutic molecular targets, focusing on the pathogenesis of non-smoker female NSCLC patients.