Which is the optimal immunotherapy for advanced squamous non-small-cell lung cancer in combination with chemotherapy: anti-PD-1 or anti-PD-L1?

Chemotherapy-induced metastasis: molecular mechanisms and clinical therapies

Chemotherapy, the most widely accepted treatment for malignant tumors, is dependent on cell death induced by various drugs including antimetabolites, alkylating agents, mitotic spindle inhibitors, antitumor antibiotics, and hormonal anticancer drugs. In addition to causing side effects due to non-selective cytotoxicity, chemotherapeutic drugs can initiate and promote metastasis, which greatly reduces their clinical efficacy. The knowledge of how they induce metastasis is essential for developing strategies that improve the outcomes of chemotherapy. Herein, we summarize the recent findings on chemotherapy-induced metastasis and discuss the underlying mechanisms including tumor-initiating cell expansion, the epithelial-mesenchymal transition, extracellular vesicle involvement, and tumor microenvironment alterations. In addition, the use of combination treatments to overcome chemotherapy-induced metastasis is also elaborated.

Programmed Cell Death Protein 1 (PD-1) and Programmed Cell Death Ligand 1 (PD-L1) Immunotherapy: A Promising Breakthrough in Cancer Therapeutics

The advent of immune checkpoint inhibitors has revolutionized cancer therapy by leveraging the body's immune system to combat malignancies effectively. Among these groundbreaking agents, programmed cell death protein 1 (PD-1) and programmed cell death ligand 1 (PD-L1) inhibitors have emerged as pivotal therapeutic approaches. PD-L1, a key protein expressed on the surface of various cells, including cancer cells, plays a central role in immune regulation by interacting with the programmed cell death protein 1 (PD-1) receptor on T-cells leading to immune suppression. The substantial increase in PD-L1 expression on cancer cell surfaces has driven the exploration of PD-1/PD-L1 inhibitors as potential immunotherapeutic agents. These inhibitors are monoclonal antibodies designed to impede the PD-L1 and PD-1 interaction and disrupt the immunosuppressive signal, thereby reinvigorating the anti-tumor immune response mediated by activated T-cells. Clinical trials investigating PD-1/PD-L1 inhibitors have demonstrated remarkable efficacy in the treatment of diverse advanced or metastatic cancers, including leukemia, non-small cell lung (NSCLC), hepatocellular, melanoma, gastric, colorectal, and breast cancers, among others. Regulatory approvals have been granted for both monotherapy and combination therapy with other cancer treatments, encompassing chemotherapy and additional immune checkpoint inhibitors. While PD-1/PD-L1 inhibitors have exhibited significant success, they are not devoid of challenges. The emergence of intrinsic or acquired resistance, as well as immune-related adverse events, warrants thorough investigation and management. Consequently, researchers have embarked on combination trials to augment the therapeutic potential of PD-1/PD-L1 inhibitors and surmount resistance mechanisms.

Navigating through the PD-1/PDL-1 Landscape: A Systematic Review and Meta-Analysis of Clinical Outcomes in Hepatocellular Carcinoma and Their Influence on Immunotherapy and Tumor Microenvironment

This systematic review aimed to assess the prognostic significance of programmed cell death-ligand 1 (PDL-1) and programmed cell death protein 1 (PD-1) in hepatocellular carcinoma (HCC). Medline, EMBASE, and Cochrane Library database searches were conducted, revealing nine relevant cohort studies (seven PDL-1 and three PD-1). Our meta-analysis showed that PD-1/PDL-1 was a marker of poor survival, regardless of the assessment method (PD-1 overall survival (OS): hazard ratio (HR) 2.40; 95% confidence interval (CI), 1.30–4.42; disease-free survival (DFS): HR 2.12; 95% CI, 1.45–3.10; PDL-1: OS: HR 3.61; 95% CI, 2.75–4.75; and DFS: HR 2.74; 95% CI, 2.09–3.59). Additionally, high level of PD-1/PDL-1 expression was associated with aging, multiple tumors, high alpha-fetoprotein levels, and advanced Barcelona Clinic Liver Cancer stage. This high level significantly predicted a poor prognosis for HCC, suggesting that anti-PD-1 therapy is plausible for patients with HCC. Furthermore, HIF-1 induces PD-1 expression, and PD1lowSOCS3high is associated with a better prognosis. Taken together, combination therapy may be the key to effective immunotherapy. Thus, exploring other markers, such as HIF-1 and SOCS3, along with PD-1/PDL-1 immunotherapy, may lead to improved outcomes.

Pharmacological tumor PDL1 depletion with chlorambucil treats ovarian cancer and melanoma: improves antitumor immunity and renders anti-PDL1-resistant tumors anti-PDL1-sensitive through NK cell effects

BACKGROUND

Tumor intracellular programmed cell death ligand-1 (PDL1) mediates pathologic signals that regulate clinical treatment responses distinctly from surface-expressed PDL1 targeted by αPDL1 immune checkpoint blockade antibodies.

METHODS

We performed a drug screen for tumor cell PDL1 depleting drugs that identified Food and Drug Administration (FDA)-approved chlorambucil and also 9-[2-(phosphonomethoxy)ethyl] guanine. We used in vitro and in vivo assays to evaluate treatment and signaling effects of pharmacological tumor PDL1 depletion focused on chlorambucil as FDA approved, alone or plus αPDL1.

RESULTS

PDL1-expressing mouse and human ovarian cancer lines and mouse melanoma were more sensitive to chlorambucil-mediated proliferation inhibition in vitro versus corresponding genetically PDL1-depleted lines. Orthotopic peritoneal PDL1-expressing ID8agg ovarian cancer and subcutaneous B16 melanoma tumors were more chlorambucil-sensitive in vivo versus corresponding genetically PDL1-depleted tumors. Chlorambucil enhanced αPDL1 efficacy in tumors otherwise αPDL1-refractory, and improved antitumor immunity and treatment efficacy in a natural killer cell-dependent manner alone and plus αPDL1. Chlorambucil-mediated PDL1 depletion was relatively tumor-cell selective in vivo, and treatment efficacy was preserved in PDL1KO hosts, demonstrating tumor PDL1-specific treatment effects. Chlorambucil induced PDL1-dependent immunogenic tumor cell death which could help explain immune contributions. Chlorambucil-mediated PDL1 reduction mechanisms were tumor cell-type-specific and involved transcriptional or post-translational mechanisms, including promoting PDL1 ubiquitination through the GSK3β/β-TRCP pathway. Chlorambucil-mediated tumor cell PDL1 depletion also phenocopied genetic PDL1 depletion in reducing tumor cell mTORC1 activation and tumor initiating cell content, and in augmenting autophagy, suggesting additional treatment potential.

CONCLUSIONS

Pharmacological tumor PDL1 depletion with chlorambucil targets tumor-intrinsic PDL1 signaling that mediates treatment resistance, especially in αPDL1-resistant tumors, generates PDL1-dependent tumor immunogenicity and inhibits tumor growth in immune-dependent and independent manners. It could improve treatment efficacy of selected agents in otherwise treatment-refractory, including αPDL1-refractory cancers, and is rapidly clinically translatable.

Efficacy and safety of pembrolizumab versus sintilimab treatment in patients with advanced squamous lung cancer: A real-world study in China

Importance

Both pembrolizumab and sintilimab have been approved by the Chinese State Drug Administration (NMPA) for the first-line treatment of patients with advanced squamous lung cancer. The differences of the two drugs in efficacy and safety are unclear.

Objectives

To compare the real-world efficacy and safety of first-line treatments in patients with advanced squamous lung cancer.

Materials and methods

This was a retrospective review of patients with advanced squamous carcinoma who received sintilimab or pembrolizumab in combination with chemotherapy as first-line therapy between June 2018 and April 2022 in the Chinese PLA Hospital. The primary objective was to compare the objective response rate (ORR), progression-free survival (PFS), and overall survival (OS) between the two groups. Secondary objectives were to compare the disease control rate (DCR) and to analyze adverse events (AEs) between the two groups.

Results

A total of 164 patients were enrolled, including 63 patients (38.4%) in the sintilimab-combined chemotherapy group and 101 patients (61.6%) in the pembrolizumab-combined chemotherapy group. The ORR was 65.10% in the sintilimab group and 61.40% in the pembrolizumab group (P=0.634). The DCR was 92.10% and 92.10% in the sintilimab and pembrolizumab groups, respectively (P=0.991). The median PFS was 22.2 months for patients treated with sintilimab group compared with 16.5 months for patients treated with pembrolizumab group[hazard ratio (HR) = 0.743; 95% confidence interval (CI): 0.479-1.152; P = 0.599]. Patients treated with pembrolizumab did not achieve a median OS, and patients treated with sintilimab had a median OS of 30.7 months. In the sintilimab group, the incidence of all treatment-related adverse events (TRAEs) was 92.1% (58/63), and the incidence of grade 3-4 TRAEs of 42.9% (27/63). In the pembrolizumab group, the incidence of all TRAEs was 90.1% (91/101), and the incidence of grade 3-4 TRAEs was 37.6% (38/101).

Conclusion

In the clinical treatment of Chinese patients with advanced squamous lung cancer, first-line treatment with sintilimab in combination with chemotherapy provided similar efficacy to pembrolizumab in combination with chemotherapy, and the treatment-related adverse effect profiles were comparable between the two groups, including similar rates of grade 3-4 and all adverse events.

Efficacy and safety of PD-1/PD-L1 immune checkpoint inhibitors in treating non-Hodgkin lymphoma: A systematic review and meta-analysis of clinical trials

BACKGROUND

Immunotherapy with programmed cell death protein-1 (PD-1)/programmed cell death ligand-1 (PD-L1) inhibitors has been widely used in the treatment of solid tumors and Hodgkin lymphoma, demonstrating powerful efficacy and good safety. However, there is no systematic review and meta-analysis to fully investigate the efficacy and safety of PD-1/PD-L1 inhibitors in treating non-Hodgkin lymphoma (NHL).

METHODS

We searched PubMed, EMBASE, The Cochrane Library, China National Knowledge Infrastructure, Wanfang database, and abstracts of conference proceedings of annual meetings up to January 23, 2022, to identify eligible clinical trials. To evaluate the efficacy of PD-1/PD-L1 inhibitors, objective response rate (ORR), complete response rate (CRR), 1-year overall survival rate, and 1-year progression-free survival rate were analyzed. For safety analysis, we calculated rates of any grade and grade ≥3 treatment-related adverse events.

RESULTS

Overall 22 studies and 1150 participants were enrolled in this meta-analysis. The pooled ORR, CRR, 1-year overall survival, and 1-year progression-free survival rates were 0.43 (95% confidence interval [CI], 0.33-0.54), 0.21 (95% CI, 0.13-0.31), 0.72 (95% CI, 0.58-0.89), and 0.42 (95% CI, 0.29-0.62), respectively. The ORR and CRR in the combination immunochemotherapy subgroup (0.65 and 0.41) were higher than those in the monotherapy (0.27 and 0.09) and combination chemotherapy (0.39 and 0.19) subgroups. This study was registered with PROSPERO (#CRD 42022316805).

CONCLUSION

Given that there were limited clinical trials and relatively few relevant studies, we conducted this meta-analysis to fully elucidate the efficacy and safety of PD-1/PD-L1 inhibitors in NHL. Our results suggested that PD-1/PD-L1 inhibitors improved outcomes of responses as well as survival rates in NHL patients with tolerable adverse events. More well-designed randomized clinical trials are still needed to further confirm our findings.

Anlotinib Hydrochloride and PD-1 Blockade as a Salvage Second-Line Treatment in Patients with Progress of Local Advanced Non-Small Cell Lung Cancer in Half a Year After Standard Treatment

Purpose

As for local advanced non-small cell lung cancer (NSCLC), synchronous radiotherapy and chemotherapy is the standard treatment mode. But for patients with progress in half a year, which means the second-line chemotherapy effect is not ideal for them. We observed the efficacy and safety of anlotinib hydrochloride combined with PD-1 blockade as the second-line treatment for those patients in this trial.

Patients and Methods

From January 2018 to December 2019, 57 patients with the progress of local advanced NSCLC treated with anlotinib plus PD-1 blockade until disease progression or intolerance as a result of adverse events. Patients have been assessed using computed tomography prior to treatment and during follow-up every 2 months until disease progression or death. The primary endpoint was objective response rate (ORR). The secondary endpoints included overall survival (OS), progression-free survival (PFS) and safety. Survival curves were created using the Kaplan-Meier method.

Results

57 patients were enrolled. The median age was 64 years, and 61.4% of the patients were men. The ORR was 50.9% with a median OS time of 14 months and the 1-year OS rates and PFS rates were 81.8% and 33.3%, respectively. The patients with squamous cell carcinoma, no brain or liver metastases had longer PFS than patients with liver metastasis. When the PFS was calculated from the time of second treatment, the median PFS was 9 months. Most adverse events (AEs) were grade 1-3, one drug-related death was noted.

Conclusion

The expected outcome of this study is that anlotinib combined with PD-1 blockade has tolerable toxicity and better ORR, OS than second-line chemotherapy. The results may indicate additional treatment options for patients with progress of local advance NSCLC in half a year after standard treatment.

The role of PD-1/PD-L1 and application of immune-checkpoint inhibitors in human cancers

Programmed cell death protein-1 (PD-1) is a checkpoint receptor expressed on the surface of various immune cells. PD-L1, the natural receptor for PD-1, is mainly expressed in tumor cells. Studies have indicated that PD-1 and PD-L1 are closely associated with the progression of human cancers and are promising biomarkers for cancer therapy. Moreover, the interaction of PD-1 and PD-L1 is one of the important mechanism by which human tumors generate immune escape. This article provides a review on the role of PD-L1/PD-1, mechanisms of immune response and resistance, as well as immune-related adverse events in the treatment of anti-PD-1/PD-L1 immunotherapy in human cancers. Moreover, we summarized a large number of clinical trials to successfully reveal that PD-1/PD-L1 Immune-checkpoint inhibitors have manifested promising therapeutic effects, which have been evaluated from different perspectives, including overall survival, objective effective rate and medium progression-free survival. Finally, we pointed out the current problems faced by PD-1/PD-L1 Immune-checkpoint inhibitors and its future prospects. Although PD-1/PD-L1 immune checkpoint inhibitors have been widely used in the treatment of human cancers, tough challenges still remain. Combination therapy and predictive models based on integrated biomarker determination theory may be the future directions for the application of PD-1/PD-L1 Immune-checkpoint inhibitors in treating human cancers.

The Effect of PD-1 Inhibitor Combined with Chemotherapy on the Level of Peripheral Blood T Lymphocytes among Patients with Non-Small-Cell Lung Cancer and Its Relationship with Prognosis

Objective

To explore the effect of combined treatment of PD-1 inhibitor and chemotherapy on the level of peripheral blood T lymphocytes in non-small-cell lung cancer (NSCLC) patients and its relationship with prognosis.

Methods

Retrospective analysis was conducted on 150 NSCLC patients treated in Guangxi Medical University Affiliated Tumor Hospital from June 2018 to September 2020, including 77 patients treated with PD-1 inhibitor combined with chemotherapy as the observation group (OG) and 73 patients with chemotherapy alone as the control group (CG). Therapeutic efficacy, immune function indexes, serum tumor markers, incidence of adverse reactions during hospitalization, 1-year survival rate, and life quality after 6 months of treatment were observed and compared between two groups.

Results

Compared to the CG, the therapeutic effect of OG was evidently better. Six months after treatment, levels of CD4⁺/CD8⁺, NK cells, and CD4 ⁺ in two groups were elevated markedly, and indexes of OG were notably and comparatively higher than those in the other group. After treatment, OG was observed with a marked decline regarding levels of CYFRA21-1, CEA, and CA125 compared to those in the CG; and there was no notable difference in terms of adverse reaction occurrence between two groups, but the 1-year survival rate and 6-month life quality in OG over ranked those in CG.

Conclusion

For NSCLC patients, the PD-1 inhibitor given on the basis of chemotherapy can further improve the clinical efficacy and improve immune function and long-term survival rate of patients on the premise of ensuring the safety of treatment, which is worth promoting in clinical practice.

Triple negative breast cancer: approved treatment options and their mechanisms of action

PURPOSE

Breast cancer, the most prevalent cancer worldwide, consists of 4 main subtypes, namely, Luminal A, Luminal B, HER2-positive, and Triple-negative breast cancer (TNBC). Triple-negative breast tumors, which do not express estrogen, progesterone, and HER2 receptors, account for approximately 15-20% of breast cancer cases. The lack of traditional receptor targets contributes to the heterogenous, aggressive, and refractory nature of these tumors, resulting in limited therapeutic strategies.

METHODS

Chemotherapeutics such as taxanes and anthracyclines have been the traditional go to treatment regimens for TNBC patients. Paclitaxel, docetaxel, doxorubicin, and epirubicin have been longstanding, Food and Drug Administration (FDA)-approved therapies against TNBC. Additionally, the FDA approved PARP inhibitors such as olaparib and atezolizumab to be used in combination with chemotherapies, primarily to improve their efficiency and reduce adverse patient outcomes. The immunotherapeutic Keytruda was the latest addition to the FDA-approved list of drugs used to treat TNBC.

RESULTS

The following review aims to elucidate current FDA-approved therapeutics and their mechanisms of action, shedding a light on the various strategies currently used to circumvent the treatment-resistant nature of TNBC cases.

CONCLUSION

The recent approval and use of therapies such as Trodelvy, olaparib and Keytruda has its roots in the development of an understanding of signaling pathways that drive tumour growth. In the future, the emergence of novel drug delivery methods may help increase the efficiency of these therapies whiel also reducing adverse side effects.

Economic evaluation of sintilimab plus chemotherapy vs. pembrolizumab plus chemotherapy for the treatment of first-line advanced or metastatic squamous NSCLC

Background and objective

Sintilimab has superior efficacy and safety in patients with advanced or metastatic squamous non-small cell lung cancer (NSCLC), but its cost-effectiveness in China is unclear. This study is to evaluate the cost-effectiveness of sintilimab plus chemotherapy vs. pembrolizumab plus chemotherapy for locally advanced or metastatic squamous NSCLC in China.

Methods

From the perspective of the Chinese health system, the partitioned survival model with three health states was established in a 3-week cycle and a lifetime time horizon. The two-stage method was used to estimate the overall survival hazard ratios to avoid the bias by crossover design in ORIENT-12 and KEYNOTE-407 studies. The anchored matching adjusted indirect comparison method (MAIC) was used for indirect comparison based on the individual patient data from ORIENT-12 and the publicly published KEYNOTE-407 study due to the lack of head-to-head clinical trials. Only direct medical costs were included, and utilities were derived from the published literature in the base case analysis. Sensitivity analysis was also performed to verify the robustness of the model results. In addition, the scenario analysis where the utilities were derived from the Quality of Life Questionnaire-Core 30 (QLQ-C30) scale in the ORIENT-12 by mapping to the EuroQol-5-dimension 5-level (EQ-5D-5L) was carried out to explore the uncertainty of the results.

Results

Compared with pembrolizumab + chemotherapy, sintilimab + chemotherapy incurred a lower lifetime cost ($12,321 vs. 36,371) and yielded fewer quality-adjusted life-years (QALYs) (0.9902 vs. 1.0085), which resulted in an incremental cost-effectiveness ratio (ICER) of $1,314,208/QALY. A sintilimab strategy is a cost-effectiveness option under the WTP of 1-3 times the GDP per capita in China ($11,250/QALY~$33,749/QALY). The utility value of the post-progression, the unit cost of albumin paclitaxel, and the utility value of the progression-free state were the main drivers in the deterministic sensitivity analysis (DSA). According to the probabilistic sensitivity analysis (PSA), sintilimab + chemotherapy was 100% cost-effective when the WTP was 1-3 times China's per capita GDP. The results of the scenario analysis showed that sintilimab + chemotherapy obtained more QALYs (1.2319 vs. 1.1815) and lower costs ($12,321 vs. 36,371), which implied that sintilimab + chemotherapy may dominate the pembrolizumab + chemotherapy.

Conclusion

Compared with pembrolizumab + chemotherapy, sintilimab + chemotherapy is more cost-effective for first-line treatment in Chinese patients with locally advanced or metastatic squamous NSCLC.

Anti-PD-1 sintilimab-induced bilateral optic neuropathy in non-small cell lung cancer: A case report and literature review

Anti-PD-1/PD-L1 immunotherapy reactivates T-cell activity to boost the antitumor effect and may trigger autoimmune toxicity in various organ systems involving eyeball and periocular structures at the same time. The rarity of ocular immune-related adverse events should not prevent us from paying attention to this issue because of the bad consequences of visual impairment. This is the first case report of anti-PD-1 sintilimab-induced bilateral optic neuropathy in a 76-year-old man with squamous non-small cell lung cancer (NSCLC). The patient presented with sudden vision blurring without pain in both eyes after three therapeutic cycles of sintilimab plus chemotherapy. Based on the ophthalmic examination, laboratory, and radiological results, our patient was diagnosed with optic neuropathy complication secondary to anti-PD-1 sintilimab treatment. Consequently, sintilimab was held and systemic steroids were administered. The follow-up review showed that the vision recovered and the size of the primary tumor continued to decrease with the response assessment as the partial response. In conclusion, this case report suggested that patients with NSCLC undergoing anti-PD-1/PD-L1 therapy should be closely monitored for ophthalmic assessment and alert to the occurrence of sintilimab-induced optic neuropathy.

Exosomal PD-L1 predicts response with immunotherapy in NSCLC patients

Immune Check-Point Inhibitors (ICIs) have shown remarkable promise in treating tumors, including non-small cell lung cancer (NSCLC). Nevertheless, the treatment response rate is low. Studies have found that the high expression of exosomal PD-L1 is one of the reasons for the low treatment response. Therefore, this study focused on the relationship between the exosomal PD-L1 and the clinical response to immunotherapy in NSCLC patients to evaluate whether it could be used as a biomarker to predict the efficacy of ICIs. In this study, clinical information and blood samples of 149 NSCLC patients receiving ICIs were collected. The expression level of exosomal PD-L1 was detected by enzyme-linked immunosorbent assay method, and the relationship between exosomal PD-L1 and the efficacy of ICIs was explored. Overall, our study found that the expression level of exosomal PD-L1 was lower at pre-treatment, or the max fold increasing change higher at 3-6 weeks had a higher disease control rate and longer progression-free survival. It revealed that the exosomal PD-L1 was associated with the treatment response of patients using ICIs and provided a new tool for the evaluation of clinical efficacy of lung cancer immunotherapy.

The Controversial Role of IL-33 in Lung Cancer

Interleukin-33 (IL-33) belongs to the interleukin-1 (IL-1) family, and its structure is similar to IL-18. When cells are damaged or undergo necrosis, mature form of IL-33 is secreted as a cytokine, which can activate the immune system and provide danger signals. The IL-33/ST2 signaling pathway is composed of IL-33, suppression of tumorigenicity 2 (ST2), and IL-1 receptor accessory protein (IL-1RAcP). IL-33 has been reported to be strongly associated with lung cancer progression, and can exhibit opposite effects on lung cancer under different conditions. In this review, we have summarized the structure and basic functions of IL-33, its possible function in immune regulation, and its role in pulmonary fibrosis as well as in lung cancer. We have highlighted the dual regulation of IL-33 in lung cancer and proposed potential lung cancer treatment regimens, especially new immunotherapies, based on its mechanism of action.

Combination Immunotherapies to Overcome Intrinsic Resistance to Checkpoint Blockade in Microsatellite Stable Colorectal Cancer

Although immune checkpoint inhibitors (ICIs) have shown promising results in the treatment of treating various malignancies, progress has been severely limited in metastatic colorectal cancer (mCRC). ICIs are effective in a fraction of patients with microsatellite instability-high mCRC but have little clinical efficacy in patients with microsatellite stable (MSS) mCRC, which accounts for 95% of mCRC cases. MSS mCRCs are considered to have intrinsic resistance to ICI monotherapy through multiple mechanisms. (1) They are poorly immunogenic because of their low tumor mutation burden; (2) frequent activation of the WNT/β-catenin signaling pathway excludes intratumoral CD8+ T cell immunity; (3) the tumor microenvironment is immunosuppressive because of the presence of various immunosuppressive cells, including tumor-associated macrophages and regulatory T cells; and (4) frequent liver metastasis in MSS mCRC may reduce the efficacy of ICIs. To overcome these resistance mechanisms, combination approaches using various agents, including STING agonists, MEK inhibitors, VEGF/R inhibitors, WNT/β-catenin inhibitors, oncolytic viruses, and chemo/radiotherapy, are actively ongoing. Preliminary evidence of the efficacy of some has been shown in early clinical trials. This review summarizes novel combination immunotherapy strategies described in recent preclinical and clinical studies to overcome the limitations of ICI monotherapy in MSS mCRC.

Reporting quality of randomized, controlled trials evaluating immunotherapy in lung cancer

BACKGROUND

With the improvement of therapeutic strategies from cytotoxic chemotherapy to immunotherapy, the possibility of achieving timely intervention for lung cancer has dramatically increased. This study aimed to systematically evaluate the reporting quality of randomized controlled trials (RCT) on immunotherapy in lung cancer.

METHODS

The RCTs evaluating the efficacy of immunotherapy in lung cancer published up to 2021 were searched and collected from PUBMED and EMBASE by two investigators. The 2010 Consolidated Standards for Test Reports (CONSORT) statement-based 28-point overall quality score (OQS) and the 2001 CONSORT statement-based 19-point OQS was utilized for assessing the overall quality of each report.

RESULTS

One hundred and fifty-two related RCTs were retrieved in this study, including 81,931 patients. The average OQS in 2010 was 17.89 (range, 7.5-24.5). Overall, studies have sufficiently reported the eligibility criteria (143/152; 94.07%), described the scientific background (150/152; 98.7%) and discussed interventions (147/152; 96.7%). However, the RCTs did not consistently report the changes to trial after commencement (48/152; 31.6%), allocation, enrollment and assignment personnel (34/152; 22.4%), blinding (48/152; 31.6%), or randomization method (58/152; 38.2%).

CONCLUSIONS

The overall reporting quality of RCTs on immunotherapy in lung cancer was found to be unsatisfactory despite the fact that the CONSORT statement was issued more than a decade ago. Furthermore, there was virtual selectivity and heterogeneity in reporting some key issues in these trials. This is the first study to enlighten lung cancer researchers especially focusing on immunotherapy, and also to remind editors and peer reviewers to strengthen their due diligence.

Comparisons of Underlying Mechanisms, Clinical Efficacy and Safety Between Anti-PD-1 and Anti-PD-L1 Immunotherapy: The State-of-the-Art Review and Future Perspectives

Over the past decade, diverse PD-1/PD-L1 blockades have demonstrated significant clinical benefit in across a wide range of tumor and cancer types. With the increasing number of PD-1/PD-L1 blockades available in the market, differences between the clinical performance of each of them started to be reported. Here, we provide a comprehensive historical and biological perspective regarding the underlying mechanism and clinical performance of PD-1/PD-L1 blockades, with an emphasis on the comparisons of their clinical efficacy and safety. The real-world evidence indicated that PD-1 blockade may be more effective than the PD-L1, though no significant differences were found as regards to their safety profiles. Future head-to-head studies are warranted for direct comparison between them. Finally, we summarize the yet to be elucidated questions and future promise of anti-PD-1/PD-L1 immunotherapy, including a need to explore novel biomarkers, novel combinatorial strategies, and their clinical use on chronic infection.

A mechanistic systems pharmacology modeling platform to investigate the effect of PD-L1 expression heterogeneity and dynamics on the efficacy of PD-1 and PD-L1 blocking antibodies in cancer

Tumors have developed multitude of ways to evade immune response and suppress cytotoxic T cells. Programed cell death protein 1 (PD-1) and programed cell death ligand 1 (PD-L1) are immune checkpoints that when activated, rapidly inactivate the cytolytic activity of T cells. Expression heterogeneity of PD-L1 and the surface receptor dynamics of both PD-1 and PD-L1 may be important parameters in modulating the immune response. PD-L1 is expressed on both tumor and non-tumor immune cells and this differential expression reflects different aspects of anti-tumor immunity. Here, we developed a mechanistic computational model to investigate the role of PD-1 and PD-L1 dynamics in modulating the efficacy of PD-1 and PD-L1 blocking antibodies. Our model incorporates immunological synapse restricted interaction of PD-1 and PD-L1, basal parameters for receptor dynamics, and T cell interaction with tumor and non-tumor immune cells. Simulations predict the existence of a threshold in PD-1 expression above which there is no efficacy for both anti-PD-1 and anti-PD-L1. Model also predicts that anti-tumor response is more sensitive to PD-L1 expression on non-tumor immune cells than tumor cells. New combination strategies are suggested that may enhance efficacy in resistant cases such as combining anti-PD-1 with a low dose of anti-PD-L1 or with inhibitors of PD-L1 recycling and synthesis. Another combination strategy suggested by the model is the combination of anti-PD-1 and anti-PD-L1 with enhancers of PD-L1 degradation rate. Virtual patients are then generated to test specific biomarkers of response. Intriguing predictions that emerge from the virtual patient simulations are that PD-1 blocking antibody results in higher response rate than PD-L1 blockade and that PD-L1 expression density on non-tumor immune cells rather than tumor cells is a predictor of response.

The Current Landscape of Immune Checkpoint Blockade in Metastatic Lung Squamous Cell Carcinoma

In addition to surgery, chemotherapy, radiotherapy, and targeted therapy, immunotherapy has emerged as a standard pillar of cancer treatment. Immune checkpoint inhibitors (ICIs) such as targeting programmed death-1/programmed death ligand 1 (PD-1/PD-L1) and cytotoxic T lymphocyte antigen 4 (CTLA-4) have been integrated into standard-of-care regimens for patients with advanced lung squamous cell carcinoma (LUSC), who were previously limited by the lack of treatment options. Atezolizumab, durvalumab, nivolumab, and pembrolizumab are all currently used as part of standard-of-care treatment for different stages of lung cancer. Recent successes and failures of immune checkpoint blockade-based combination therapies have provided significant insights into implementing combination strategies in LUSC. Therefore, there is an urgent need to correctly select patients who are more likely to respond to immunotherapy and understand the mechanisms of primary or acquired resistance. In this review, we aim at summarizing the emerging clinical data on the promise and challenge of ICIs, discussing the unmet need of potential biomarkers for predicting response or resistance to immunotherapy, and providing an overview of the current immune landscape and future directions in advanced LUSC.

Evolution of Lung Cancer in the Context of Immunotherapy

Immunotherapy, as a novel treatment, has brought new hope to many patients with cancer, including patients with lung cancer. However, the overall cure rate and survival rate of lung cancer are still not satisfactory. The process of evolution has improved the ability of tumors to adapt to immunotherapy, which induces drug resistance. Many studies have focused on immunoresistance and achieved meaningful results. Therefore, it is necessary to have an in-depth understanding of the current research progress in immunoresistance, which will help to achieve good clinical results more efficiently.

Use of Immunotherapy With Programmed Cell Death 1 vs Programmed Cell Death Ligand 1 Inhibitors in Patients With Cancer: A Systematic Review and Meta-analysis

Importance

Immune checkpoint inhibitors of programmed cell death 1 (PD-1) and its ligand (PD-L1) have led to a paradigm shift in cancer treatment. Understanding the clinical efficacy and safety profile of these drugs is necessary for treatment strategy in clinical practice.

Objective

To assess the differences between anti-PD-1 and anti-PD-L1 regarding efficacy and safety shown in randomized clinical trials across various tumor types.

Data Sources

Systematic searches of PubMed, Cochrane CENTRAL, and Embase were conducted from January 1, 2000, to March 1, 2019. In addition, abstracts and presentations from all major conference proceedings were reviewed.

Study Selection

All randomized clinical trials that compared anti-PD-1 and anti-PD-L1 with standard treatment in patients with cancer were selected as candidates. Retrospective studies, single-arm phase 1/2 studies, and trials comparing anti-PD-1 and anti-PD-L1 with other immunotherapies were excluded. Studies of anti-PD-1 and anti-PD-L1 therapy were screened and paired by the matching of clinical characteristics as mirror groups.

Data Extraction and Synthesis

Three investigators independently extracted data from each study following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guideline. Trial names, first author, year of publication, study design, National Clinical Trial identifier number, blinding status, study phase, pathologic characteristics, number of patients, patients' age and sex distribution, Eastern Cooperative Oncology Group Performance Status, lines of treatment, study drugs, biomarker status, follow-up time, incidence of adverse events, and hazard ratios (HRs) with 95% CIs for overall survival and progression-free survival were extracted. A random-effects model was applied for data analysis.

Main Outcomes and Measures

Differences in OS between anti-PD-1 and anti-PD-L1 across different cancer types were assessed. An effect size was derived from each mirror group and then pooled across all groups using a random-effects model.

Results

Nineteen randomized clinical trials involving 11 379 patients were included in the meta-analysis. Overall, anti-PD-1 exhibited superior overall survival (HR, 0.75; 95% CI, 0.65-0.86; P < .001) and progression-free survival (HR, 0.73; 95% CI, 0.56-0.96; P = .02) compared with anti-PD-L1. No significant difference was observed in their safety profiles. Sensitivity analysis presented consistency in the overall estimates across these analyses. Consistent results were observed through frequentist and bayesian approaches with the same studies.

Conclusions and Relevance

Comprehensive analysis suggests that anti-PD-1 exhibited favorable survival outcomes and a safety profile comparable to that of anti-PD-L1, which may provide a useful guide for clinicians.

First-line immune-checkpoint inhibitor plus chemotherapy versus chemotherapy alone for extensive-stage small-cell lung cancer: a meta-analysis

Introduction

Platin-based chemotherapy (CT) has long been the first-line standard-of-care for patients with extensive-stage small-cell lung cancer (ES-SCLC). Adding immune-checkpoint inhibitor(s) to CT (ICI+CT) in this setting is an option of interest, although its benefit is apparently modest.

Methods

This meta-analysis was conducted on randomized trials comparing first-line ICI+CT versus CT alone for ES-SCLC. Outcomes included overall survival (OS), progression-free survival (PFS), objective response rate (ORR), response at 12 months and adverse events (AEs). Subgroup analyses were computed according to the immunotherapy used, performance status (PS), age, platinum salt, liver metastases and brain metastases at diagnosis.

Results

The literature search identified one randomized phase II (ECOG-ACRIN-5161) and four phase III trials (CASPIAN, IMPOWER-133, KEYNOTE-604 and Reck et al. 2016) that included 2775 patients (66% males, 95% smokers, median age: 64 years, PS = 0 or 1). ICI+CT was significantly associated (hazard ratio [95% confidence interval]) with prolonged OS [0.82 (0.75-0.89); p <  0.00001] and PFS [0.81 (0.75-0.87); p <  0.00001], with OS benefits for anti-PD-L1 [0.73 (0.63-0.85); p < 0.0001] or anti-PD-1 [0.76 (0.63-0.93); p < 0.006] but not for anti-CTLA-4 [0.90 (0.80-1.01), p = 0.07]. ORRs for ICI+CT or CT alone were comparable [odds ratio 1.12 (0.97-1.00); p = 0.12], but responses at 12 months favored ICI+CT [4.16 (2.81-6.17), p < 0.00001]. Serious grade-3/4 AEs were more frequent with ICI+CT [odds ratio 1.18 (1.02-1.37); p = 0.03]. Compared with CT, no ICI+CT benefit was found for ES-SCLC with brain metastases at diagnosis [HR 1.14 (0.87-1.50); p = 0.34].

Conclusions

First-line ICI+CT appears to be superior to CT alone for ES-SCLC except for patients with brain metastases at diagnosis.

The optimal immune checkpoint inhibitors combined with chemotherapy for advanced non-small-cell lung cancer: a systematic review and meta-analysis

BACKGROUND

Immune checkpoint inhibitors (ICIs) plus chemotherapy (CT) have strikingly expanded the therapeutic landscape for advanced non-small cell lung cancer (NSCLC), but little is known about which is superior. We performed a meta-analysis that compared the efficacy and safety of PD-1 inhibitor + CT with PD-L1 inhibitor + CT.

METHODS

PubMed, Embase, Web of Science, Cochrane Library, and major international scientific meetings were searched for relevant randomized controlled trials (RCTs), and the indirect analysis was performed for PD-1 + CT vs PD-L1 + CT. The outcomes included progression-free survival (PFS), overall survival (OS), objective response rate (ORR) and treatment-related adverse events (TRAEs).

RESULTS

8 phase III RCTs with 4253 patients comparing PD-1/PD-L1 + CT in NSCLC were included. The PD-1 + CT led to notably longer OS most in low/negative expression of PD-L1 for NSCLC patients compared with PD-L1 + CT. In terms of Grade 3-5 TRAEs, the results showed that PD-1 + CT and PD-L1 + CT exclusively increased the risk of adverse incidence than CT alone, especially for PD-L1 + CT (p < 0.00001). For subgroups including female, young patients, patients with nonsmoker, and EGFR/ALK wild-type, PD-1 + CT was associated with prolonged OS (p < 0.05). Meanwhile, for no liver metastasis of NSCLC patients, we found obviously OS advantage for patients treated with PD-1 + CT compared to PD-L1 + CT.

CONCLUSIONS

ICIs + CT seemed to be more effective first-line regimen and PD-1 + CT could be recommended as the first-rank therapy for advanced NSCLC patients with low/negative expression of PD-L1. However, we should be particularly vigilant about the occurrence of the Grade 3-5 TRAEs.

Role of extracellular vesicles in tumour microenvironment

In recent years, it has been demonstrated that extracellular vesicles (EVs) can be released by almost all cell types, and detected in most body fluids. In the tumour microenvironment (TME), EVs serve as a transport medium for lipids, proteins, and nucleic acids. EVs participate in various steps involved in the development and progression of malignant tumours by initiating or suppressing various signalling pathways in recipient cells. Although tumour-derived EVs (T-EVs) are known for orchestrating tumour progression via systemic pathways, EVs from non-malignant cells (nmEVs) also contribute substantially to malignant tumour development. Tumour cells and non-malignant cells typically communicate with each other, both determining the progress of the disease. In this review, we summarise the features of both T-EVs and nmEVs, tumour progression, metastasis, and EV-mediated chemoresistance in the TME. The physiological and pathological effects involved include but are not limited to angiogenesis, epithelial-mesenchymal transition (EMT), extracellular matrix (ECM) remodelling, and immune escape. We discuss potential future directions of the clinical application of EVs, including diagnosis (as non-invasive biomarkers via liquid biopsy) and therapeutic treatment. This may include disrupting EV biogenesis and function, thus utilising the features of EVs to repurpose them as a therapeutic tool in immunotherapy and drug delivery systems. We also discuss the overall findings of current studies, identify some outstanding issues requiring resolution, and propose some potential directions for future research. Video abstract.

Impact of ALK variants on brain metastasis and treatment response in advanced NSCLC patients with oncogenic ALK fusion

Background

To investigate the impact of ALK variants on the features of brain metastases (BM), the outcome of chemotherapy and targeted therapy using crizotinib, as well as the progression pattern in patients with ALK fusion.

Methods

Patients with ALK fusion were retrospectively collected from January 2013 to July 2017 in Shanghai Pulmonary Hospital. ALK rearrangements were identified via ARMS-PCR. ALK variants were identified via Sanger Sequencing.

Results

A total of 135 patients and 41 with brain metastasis were identified. Radiological features showed that the patients with ALK variant 1 had a larger BM size compared with patients with ALK non-variant 1 (median tumor size: 16.89 vs. 11.01 mm, P=0.031). Similar time to treatment failure (TTF) was observed in patients with ALK variant 1 and non-variant 1 who received first-line crizotinib (median TTF: 15.7 vs. 13.8 months, HR =0.75, P=0.34). Patients with ALK variant 1 who had baseline BM had significantly shorter TTF than non-variant 1 with baseline BM when treated with first-line crizotinib (median TTF: 9.1 vs. 14.9 months, HR =2.68, P=0.037). In patients treated with chemotherapy, ALK variant 1 was associated with inferior TTF (median TTF: 5.6 vs. 8.1 months, HR =1.66, P=0.039). Progression pattern was similar between ALK variant 1 and non-variant 1.

Conclusions

Patients with ALK variant 1 and baseline BM had inferior TTF on first-line crizotinib treatment and presented with more aggressive radiological features. Patients with ALK non-variant 1 had better clinical outcome on first-line chemotherapy.

Combination of Immune Checkpoint Inhibitors with Chemotherapy in Lung Cancer

Tremendous progress has been achieved in the field of immune checkpoint inhibitors (ICIs) therapy in lung cancer in recent years. To generate robust, long-lasting anti-tumor immune responses in lung cancer patients, combinational ICI therapies have been explored deeply. Conventionally, chemotherapy was considered as immunosuppressive. It is now recognized that chemotherapy could also reinstate cancer cell immune-surveillance and enable the perception of cancer cells as dangerous. That is to say that chemotherapeutic drugs are not only a source of direct cytotoxic effects but also an adjuvant for anti-tumor immunity. Recently, multiple clinical studies of ICIs combined with chemotherapeutic drugs have been explored and proved effective. However, there are still crucial questions that are not well addressed, such as the optimal dose and schedule for a given combination may differ across disease indications, and the appropriate strategy of selecting patient population that can benefit from ICIs remains unclear. To facilitate more rational lung cancer ICIs therapy development, this review summarizes the immune-regulatory effects and related mechanisms of chemotherapeutic drugs and the clinical progress of ICIs and their combination with chemotherapies in lung cancer treatment.

Are anti-PD1 and anti-PD-L1 alike? The non-small-cell lung cancer paradigm

Anti-PD1 and anti-PD-L1 agents may have intrinsic and clinically relevant differences in the treatment of non-small cell lung cancer (NSCLC) patients. By reviewing currently available indirect evidence on these agents for NSCLC treatment, highlighting possible inter- and intra-class dissimilarities, anti-PD1 agents showed a higher response rate and a better outcome when combined with chemotherapy for the first-line treatment of patients with squamous and PD-L1 low advanced NSCLC, as compared to anti-PD-L1 agents. Conversely, anti-PD-L1 agents were responsible for less severe adverse events (AEs), particularly, immunerelated AEs. These differences could be explained by their different specific properties. Considering possible differences between anti-PD1 and anti-PD-L1 agents could be clinically relevant for treatment tailoring and inspiring new investigational approaches.

PD-1 Pandemonium at the American Association for Cancer Research Annual Meeting

This editorial describes the results of discussions between the U.S. FDA Oncology Center of Excellence and members of six pharmaceutical companies—a forum aptly named PD‐1 Pandemonium—regarding development and regulatory approvals of immune checkpoint inhibitors.

Treatment- and immune-related adverse events of immune checkpoint inhibitors in advanced lung cancer

BACKGROUND

Immune checkpoint inhibitors (ICIs) emerged as the preferred therapy in advanced lung cancer, understanding the treatment- and immune-related adverse events of these drugs is of great significance for clinical practice.

MATERIALS AND METHODS

PubMed, Embase, Cochrane library and major conference proceedings were systematically searched for all randomized controlled trials (RCTs) in lung cancer using PD-1/PD-L1/CTLA-4 inhibitors. The outcomes included treatment-related adverse events (TRAEs) and several organ specific immune-related adverse events (IRAEs).

RESULTS

24 RCTs involving 14,256 patients were included. There was a significant difference for ICI therapy in the incidence of any grade of TRAEs (RR: 0.90; 95%CI: 0.84-0.95; P=0.001) and a lower frequency of grade 3-5 of TRAEs (RR: 0.65; 95%CI: 0.51-0.82; P<0.001). Patients treated with ICI therapy in non-small-cell lung cancer (NSCLC) were less reported TRAEs than in small cell lung cancer (SCLC). A lower risk of TRAEs was favored by anti-PD-1 inhibitors over anti-PD-L1 antibodies and anti-CTLA-4 drugs. The most common organ specific IRAE was hypothyroidism that occurred 8.7%. The incidence of pneumonitis and hepatitis reached 4.5% and 4.0% respectively. Compared with patients treated in control arms, those treated with ICI drugs were at higher risk for each organ specific adverse event including colitis, hepatitis, pneumonitis, hypothyroidism and hypophysitis.

CONCLUSIONS

ICI therapy was safer than chemotherapy, especially ICI monotherapy such as anti-PD-1 antibodies in NSCLC. Compared with standard treatments, ICI drugs increased the risk of organ-specific IRAEs, although the overall incidence remained low.

Immune Checkpoint Inhibitors in Lung Cancer: Role of Biomarkers and Combination Therapies

Lung cancer is the leading cause of cancer-related death worldwide, with a poor prognosis. Despite aggressive treatment, progression-free survival (PFS) and overall survival are limited. Recently, various kinds of immune checkpoint inhibitors (ICIs) have emerged for several cancers, targeting PD1, PDL1, and CTLA-4. ICIs have made a significant breakthrough in cancer and revolutionized the management of cancer including lung cancer. However, there are a lot of controversies regarding which group of patients is most suitable to be treated with ICIs in terms of monotherapy, combination, and predictive biomarkers. We reviewed various kinds of studies, such as meta-analysis, randomized control trials, multi-center cohort studies, and case-control studies from PubMed written in English from the last five years. ICIs have significant benefits in the overall survival compared with traditional chemotherapy. Patients with a higher level of PDL1 expression and high tumor mutational burden (TMB) have a higher response rate, and those with EGFR-/ALK- were better than those with EGFR+/ALK+. The patient who responded to immunotherapy completely can still maintain the efficacy after two years of treatment. Neoadjuvant immunotherapy in patients with resectable non-small cell lung cancer resulted in a 45% major pathology response (MPR) and 40% downstaging. Combined therapy (ICIs + chemotherapy) was better than chemotherapy alone, irrespective of PD-L1 expression. A combination of ICIs such as CTLA-4 and PD-1/PD-L1 improved PFS as well. Radiochemotherapy ahead of ICIs is promising as well. However, ICIs combined with EGFR/ALK-TKI (tyrosine kinase inhibitor) are not suggested for the time being. PDL1 expression, TMB, and EGFR/ALK mutations are promising predictive biomarkers. Gut microbiota, galectin-3, and intensity of CD8 cell infiltration are other potential predictive biomarkers. These are very important in the future management of lung cancers as they can prevent unnecessary toxicities and cost of treatment.

POLE2 Serves as a Prognostic Biomarker and Is Associated with Immune Infiltration in Squamous Cell Lung Cancer

Background

Squamous cell lung cancer is the main cause of cancer-associated mortality. The discovery of promising prognostic biomarkers for predicting the survival of patients with squamous cell lung cancer remains a challenge.

Material/Methods

Gene expression profiles of GSE33479 and GSE51855, including 42 squamous cell lung cancer tissues and 17 normal tissues, from the GEO database were assessed to find common differentially expressed genes (DEGs) via the GEO2R online tool and Venn diagram software. Then, gene ontology (GO) and Kyoto Encyclopedia of Gene and Genome (KEGG) pathway analyses were conducted. The key protein-protein interaction (PPI) network within those common DEGs was subsequently illustrated through a combination of Search Tool for Retrieval of Interacting Genes (STRING) and Cytoscape software. Finally, core genes associated with survival and levels of immune infiltration were demonstrated by the Kaplan-Meier plotter and Tumor Immune Estimation Resource (TIMER) online database, respectively.

Results

In total, 483 DEGs were involved, including 216 upregulated genes enriched in “cell division”, “DNA replication”, and “DNA repair pathway” and 267 downregulated genes enriched in “cell adhesion”, “oxidation-reduction process”, and “cell-cell signaling”. The 75 core genes were selected by Molecular Complex Detection applied in Cytoscape. Four genes – MND1, FOXM1, CDC6, and POLE2 – were found to be significantly associated with survival. Further analysis of the KEEG pathway and TIMER database revealed that only POLE2 was enriched in “DNA replication” and its higher expression was negatively associated with survival and immune infiltration.

Conclusions

Higher expression of POLE2 is a prognosis-related biomarker for worse survival and is negatively associated with immune infiltration in squamous cell lung cancer.

PD-L1:CD80 Cis-Heterodimer Triggers the Co-stimulatory Receptor CD28 While Repressing the Inhibitory PD-1 and CTLA-4 Pathways

Combined immunotherapy targeting the immune checkpoint receptors cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed cell death 1 (PD-1), or CTLA-4 and the PD-1 ligand (PD-L1) exhibits superior anti-tumor responses compared with single-agent therapy. Here, we examined the molecular basis for this synergy. Using reconstitution assays with fluorescence readouts, we found that PD-L1 and the CTLA-4 ligand CD80 heterodimerize in cis but not trans. Quantitative biochemistry and cell biology assays revealed that PD-L1:CD80 cis-heterodimerization inhibited both PD-L1:PD-1 and CD80:CTLA-4 interactions through distinct mechanisms but preserved the ability of CD80 to activate the T cell co-stimulatory receptor CD28. Furthermore, PD-L1 expression on antigen-presenting cells (APCs) prevented CTLA-4-mediated trans-endocytosis of CD80. Atezolizumab (anti-PD-L1), but not anti-PD-1, reduced cell surface expression of CD80 on APCs, and this effect was negated by co-blockade of CTLA-4 with ipilimumab (anti-CTLA-4). Thus, PD-L1 exerts an immunostimulatory effect by repressing the CTLA-4 axis; this has implications to the synergy of anti-PD-L1 and anti-CTLA-4 combination therapy.

The efficacy of PD-1/PD-L1 inhibitors in advanced squamous-cell lung cancer: a meta-analysis of 3112 patients

Aim: We performed a meta-analysis to explore the efficacy of immunotherapy for patients with squamous non-small-cell lung cancer (NSCLC). Materials & methods: Randomized clinical trials comparing immunotherapy with chemotherapy for advanced NSCLC patients were included. Results: A total of 11 trials (3112 patients) were included. PD-1/PD-L1 inhibitors demonstrated significant superiority to chemotherapy in overall survival (OS) (hazard ratio [HR]: 0.74; p < 0.001) and progression-free survival (PFS) (HR: 0.66; p < 0.001) for squamous NSCLC. The OS and PFS benefits of PD-1/PD-L1 inhibitors for squamous NSCLC were similar in subgroup analyses of line settings, PD-L1 expression and different study methodologies. No advantage in OS was found in advanced squamous NSCLC patients treated with atezolizumab (HR: 0.87; p = 0.087). Conclusion: PD-1/PD-L1 inhibitors significantly improved OS and PFS in advanced squamous NSCLC patients when compared with chemotherapy.

The role of exosomal PD-L1 in tumor progression and immunotherapy

Programmed death ligand 1 (PD-L1), a type I transmembrane protein, binds to its receptor PD-1 to suppress the activation of T cells, thereby maintaining immunological homeostasis. In contrast, tumor cells highly express PD-L1, which binds to receptor PD-1 expressed on activated T cells, leading to immune escape. Anti-PD-1/PD-L1 immune checkpoint therapy blocks the binding of PD-1/PD-L1 to reinvigorate the exhausted T cells, thereby inhibiting tumor growth. Exosomes are biologically active lipid-bilayer nanovesicles secreted by various cell types that mediate intercellular signal communication. Numerous studies have shown that tumor cells are able to promote tumor epithelial-mesenchymal transition, angiogenesis, and immune escape by releasing exosomes. Recent studies imply that tumor-derived exosomes could carry PD-L1 in the same membrane topology as the cell surface, thereby resisting immune checkpoint therapy. In this review, we mainly discuss the role of exosomes in the regulation of tumor progression and the potential resistance mechanism to immunotherapy via exosomal PD-L1. In addition, we propose that exosomal PD-L1 may have the potential to be a target to overcome resistance to anti-PD-1/PD-L1 antibody therapy.

Impact of clinicopathological features on the efficacy of immune checkpoint inhibitors plus conventional treatment in patients with advanced lung cancer

Background

To investigate the impact of different immune checkpoint inhibitors (ICI), programmed-death ligand 1 (PD-L1) expression and clinical characteristics on clinical outcome of ICI plus conventional treatment in advanced lung cancer patients.

Methods

Randomized clinical trials that compared combination therapy versus control group were screened in PubMed, EMBASE, Web of Science, Cochrane Library and included. The pooled hazard ratio (HR) with a 95% confidence interval (95% CI) were used to estimate associations. Cochrane Collaboration tool was used for quality assessment.

Results

Thirteen clinical trials were included (n=9,241). The pooled results indicated that combination strategy based on ICI significantly improved PFS (HR =0.66, P<0.001) and OS (HR =0.77, P<0.001) in overall population. Greatest PFS improvement was seen in group of PD-1 based combination (HR =0.54, P<0.001), followed by PD-L1 based (HR =0.66, P<0.001) and CTLA-4 based combination (HR =0.86, P=0.002) (interaction: P<0.001).The improvement in PFS did proportionally differ by PD-L1 expression (interaction: P<0.001). OS HRs favored combination in patients with negative or strong positive group of PD-L1 expression not in the group of weak positive group (HR =0.77, P=0.12). Subgroup analysis demonstrated that OS benefit could be observed in male (HR =0.82, P=0.03), current or former smokers (HR =0.74, P=0.04), non-squamous (HR =0.71, P<0.001) and patients without driver mutations (HR =0.73, P<0.001). OS benefit rather than PFS benefit was appeared in patients with liver metastasis treated with ICI-based combination (HR =0.74, P=0.005).

Conclusions

ICI plus conventional treatment could significantly improve PFS and OS in overall advanced lung cancer patients. PD-1-based combination leads to the greatest improvement in both PFS and OS. More data are warranted to address the association of PD-L1 staining intensity with OS improvement. Male, current or former smokers, non-squamous and patients without driver mutations do benefit from ICI-based combination.

Rational application of the first-line chemotherapy and immune checkpoint inhibitors in advanced nonsmall cell lung cancer: A meta-analysis

Objective

To compare the relative efficacy of immune checkpoint inhibitors (ICIs) or chemotherapy (CT) alone, or their combination modality in the first‐line treatment of advanced nonsmall cell lung cancer (NSCLC).

Methods

This meta‐analysis was performed on the eligible randomized controlled trials (RCTs) after searching web databases and meeting abstracts. The main research endpoints were the comparisons of median overall survival (mOS), the OS rate of 6 months (OSR6m), 1 year (OSR1y) and 2 years (OSR2y), median progression‐free survival (mPFS), the PFS rate of 6 months (PFSR6m) and 1‐year (PFSR1y), objective response rates (ORR), and treatment‐related adverse events (TRAEs).

Results

Eleven RCTs comprising 6278 cases were included. In the subgroup of programmed death‐ligand 1 (PD‐L1) ≥50%, compared with chemotherapy, the ICIs showed similar OSR6m (P > 0.05), but significantly improved efficacy in mOS, OSR1y, OSR2y, and ORR (all P < 0.05), also had less grade ≥ 3 TRAEs. Compared with pembrolizumab alone, pembrolizumab plus CT in the subgroup of PD‐L1 ≥ 50% had similar mOS, OSR6m, OSR1y, and PFSR1y (all P > 0.05), but significantly improved mPFS, PFSR6m, and ORR (all P < 0.05 for interaction). Compared with the CT group, ICIs plus CT group with PD‐L1 ≥ 50% or <1% showed significant benefit in OS, PFS, and ORR (all P < 0.05). However, in the ICIs plus CT group with 1% ≤ PD‐L1 ≤ 49%, only PFS and ORR showed significant benefit compared with CT group (all P < 0.05), but not for results of OS.

Conclusions

The findings support the rationale for using pembrolizumab alone in the first‐line treatment of PD‐L1 ≥ 50% advanced NSCLC due to the similar OS and lower grade ≥ 3 TRAEs. However, the combination of ICIs and chemotherapy is strongly recommended in patients with PD‐L1 ≤ 49% for significant survival benefit.