Background: Immune checkpoint inhibitors (ICIs) have significant clinical efficacy in the treatment of non‐small cell lung cancer (NSCLC); however, the incidence of immune‐related adverse events (irAEs) of up to 50% has prevented their widespread use. With the increase in the use of ICIs alone or as combination therapy, clinicians are required to have a better understanding of irAEs and be able to manage them systematically. In this study, we aimed to assess the incidence of irAEs associated with ICIs.Methods: We searched PubMed, Embase, and the Web of Science databases, and also included relevant literature references to widen our search. The relevant data with inclusion criteria were performed using RevMan 3.6.0 for meta‐analysis. We undertook a systematic literature search which included published data up to December 2019.Results: Overall, 147 articles and 23 761 cancer patients with 11 different ICI treatment‐related (grade 1–5 and 3–5) irAEs were included in the study. There were 46 articles on pembrolizumab (6598 patients), 27 on nivolumab (3576 patients), 13 on atezolizumab (2787 patients), 12 on avelumab (3213 patients), 10 on durvalumab (1780 patients), 22 on ipilimumab (4067 patients), eight on tremelimumab (1158 patients), three on JS001 (223 patients), four on camrelizumab (SHR‐1210) (178 patients), one on sintilimab (96 patients), and one on cemiplimab (85 patients). Grade 1–5 irAEs were: cytotoxic T lymphocyte antigen 4 (CTLA‐4) (82.87%), programmed cell death 1 (PD‐1) (71.89%), and programmed cell death ligand‐1 (PD‐L1) (58.95%). Subgroup analysis was: Avelumab (44.53%), durvalumab (66.63%), pembrolizumab (67.25%), atezolizumab (68.77%), nivolumab (76.25%), Ipilimumab (82.18%), and tremelimumab (86.78%). Grade 3–5 irAEs were: CTLA‐4 (27.22%), PD‐1(17.29%), and PD‐L1(17.29%). Subgroup analysis was: Avelumab (5.86%), durvalumab (13.43%), atezolizumab (14.45%), nivolumab (15.72%), pembrolizumab (16.58%), tremelimumab (22.04%), and ipilimumab (28.27%).Conclusions: This meta‐analysis confirmed that anti‐PD‐1 and anti‐PD‐L1 inhibitors had a lower incidence of irAEs compared with anti‐CTLA‐4 inhibitors.

Background: Many immune checkpoint inhibitors (ICIs) have been approved in China to treat non‐small cell lung cancer (NSCLC). However, in the long term, less than 20% of patients benefit from ICIs. To maximize the benefit for NSCLC patients, it is necessary to guide the choice of immunotherapy through biomarkers. Recent studies have shown that gut microbiota can affect tumor response to immunotherapy and might be a potential predictive biomarker. This study analyzed the relationship between intestinal flora structure and metabolomic characteristics in NSCLC and the efficacy of ICIs.Methods: Prospective analysis of samples from 63 patients with advanced NSCLC who attended the Department of Respiratory Medicine of the Peking Union Medical College Hospital from March 2018 to June 2019, and were prescribed programmed cell death 1 (PD‐1) inhibitors, was carried out. The follow‐up deadline was 31 December 2019. Stool samples were collected from all patients before the start of immunotherapy. DNA was extracted from all samples and libraries were constructed. This was followed by sequencing using the Illumina sequencing platform, and results were studied using a biological information data analysis process. We divided the data into two groups based on progression‐free survival (PFS) ≥ six months and PFS < six months.Results: The median PFS was 7.0 months, not reaching the median overall survival (OS). We obtained 373.5 G of original sequencing data. The phyla Bacteroidetes, Firmicutes, Proteobacteria, and Actinobacteria accounted for most of the bacterial communities in the stool samples studied. Compared with the PFS < six‐month group, the patients in the PFS ≥ six‐month group had significantly higher β‐diversity in the intestinal microbiome at the baseline level. There were also differences in composition between the two groups. Samples in the PFS ≥ six‐month group were rich in Parabacteroides and Methanobrevibacter, while those in the PFS < six‐month group were rich in Veillonella, Selenomonadales, and Negativicutes. The KO, COG, and CAZy databases were used to study functional group protein families, yielding 390 (KO), 264 (COG), and 859 (CAZy) functional group abundances, with significant differences between the two groups. Bacterial metabolites analysis suggested significant differences in the metabolic potential of methanol and methane between the two groups.Conclusions: We found a close correlation between intestinal microbiome β‐diversity and anti‐PD‐1 immunotherapy response in Chinese patients with advanced NSCLC. The intestinal flora composition, functional group protein family, and KEGG metabolism also differed between the two groups. Differences in pathways and flora metabolites were also noted.

IL‐6 is a cytokine that plays an important role in response to injury or infection and is a promising biomarker for predicting poor prognosis and therapeutic targets in non‐small cell lung cancer (NSCLC). This article reviews the biochemical mechanism, function and genotype of IL‐6, and summarizes the diagnostic and prognostic value of IL‐6 level. Anti‐IL‐6 therapy does not affect the effect of immunocheckpoint inhibitors (ICIs), but enhances its anticancer function, which may be the treatment option for immune‐related adverse events (irAEs) in the future. Therefore, IL‐6 may be a therapeutic target for the treatment of NSCLC.

Immune checkpoint inhibitors (ICIs) are able to reactivate the immune system, thereby enhancing the anti‐tumor effects. However, over‐activated T cells may induce immune‐related adverse events (irAEs). Hematological irAEs are rarely reported which mainly represent monolineage cytopenia or pancytopenia, including autoimmune hemolytic anemia (AIHA), immune thrombocytopenia (ITP), neutropenia and aplastic anemia, sometimes even life‐threatening diseases such as hemophagocytic lymphohistiocytosis. Here, the clinical manifestations of hematological irAEs are summarized and recommendations for diagnosis and treatment proposed.Key points: Significant findings of the study: • Hematological immune‐related adverse events (irAEs) caused by checkpoint inhibitors are rare and may sometimes be life‐threatening. This study summarizes the manifestations of hematological irAEs and proposes preliminary recommendations for diagnosis and treatment.What this study adds: • Much still remains unknown regarding hematological irAEs caused by checkpoint inhibitors. This study delineates the overview of hematological irAEs, and provides practical treatment suggestions, in particular addressing the issue of rechallenge.

To summarize the therapeutic effects of PD-1/PD-L1 inhibitors on patients with advanced non-small cell lung cancer (NSCLC) in a real-world setting, we attempted to identify potential molecular biomarkers or clinical factors that reflected the therapeutic effect. The medical records of patients with non-small cell lung cancer who were treated with PD-1/PD-L1 inhibitors were obtained from the outpatient department or inpatient department of Peking Union Medical College Hospital from August 1, 2015, to January 1, 2018. Our follow-up continued until May 1,2018. We chose overall survival (OS) as the primary observation endpoint and progression-free survival (PFS), objective response rate (ORR), disease control rate (DCR), and safety as the secondary observation endpoints. Efficacy was evaluated according to the Response Evaluation Criteria in Solid Tumors (RECIST) 1.1. The Kaplan-Meier method was used to generate survival curves, and we compared the influence of different factors on PFS and OS by the log-rank test. The median follow-up time was 11 months. At the end of the follow-up, 24 patients (61.5%) were still undergoing immunotherapy, and 7 patients (17.9%) had died. Twenty-six cases (66.7%) employed PD-1/PD-L1 inhibitors as first-line treatment, and 7 cases (17.9%) employed PD-1/PD-L1 inhibitors as second-line treatment. Only 6 cases (15.4%) employed PD-1/PD-L1 inhibitors as third-line treatment. Therapeutic effect evaluation: Complete response (CR): 1 case (2.6%). Partial response (PR): 10 cases (25.6%). Stable disease (SD): 16 cases (41.0%). Progressive disease (PD): 12 cases (30.8%). The ORR was 28.2%, and DCR was 69.2%. The median PFS was 25.5 months (95% CI 6.8–44.1 months), which failed to reach the median OS. PD-1/PD-L1 inhibitor treatment is more effective for advanced non-small cell lung cancer patients in a real-world setting than in clinical trials; PD-1/PD-L1 inhibitor treatment is more effective for people who are over 70 than for people who are under 70. Additionally, patients who are over 75 years old have a higher response rate, suggesting that elderly patients may receive more benefits from immunotherapy; Patients who have an epidermal growth factor receptor (EGFR) mutation (+) may benefit from immunotherapy after treatment with a tyrosine kinase inhibitor (TKI). It is essential to identify these potential patients from the entire patient pool; PD-1 may have a certain curative effect on brain metastases from NSCLC. Local radiotherapy may help to improve PD-1 intracranial efficacy.