Combined VEGF and PD-L1 Blockade Displays Synergistic Treatment Effects in an Autochthonous Mouse Model of Small Cell Lung Cancer

The missing link between cancer stem cells and immunotherapy

Cancer stem cells (CSCs) are cancer cells that can self-renew and give rise to tumors. The multipotency of CSCs enables the generation of diverse cancer cell types and their potential for differentiation and resilience against chemotherapy and radiation. Additionally, specific biomarkers have been identified for them, such as CD24, CD34, CD44, CD47, CD90, and CD133. The CSC model suggests that a subset of CSCs within tumors is responsible for tumor growth. The tumor microenvironment (TME), including fibroblasts, immune cells, adipocytes, endothelial cells, neuroendocrine (NE) cells, extracellular matrix (ECM), and extracellular vesicles, has a part in shielding CSCs from the host immune response as well as protecting them against anticancer drugs. The regulation of cancer stem cell plasticity by cancer-associated fibroblasts (CAFs) occurs through specific signaling pathways that differ among various types of cancer, utilizing the IGF-II/IGF1R, FAK, and c-Met/FRA1/HEY1 signaling pathways. Due to the intricate dynamics of CSC proliferation, controlling their growth necessitates innovative approaches and much more research. Our current review speculates an outline of how the TME safeguards stem cells, their interaction with CSCs, and the involvement of the immune and inflammatory systems in CSC differentiation and maintenance. Several technologies have the ability to identify CSCs; however, each approach has limitations. We discuss how these methods can aid in recognizing CSCs in several cancer types, comprising brain, breast, liver, stomach, and colon cancer. Furthermore, we explore different immunotherapeutic strategies targeting CSCs, including stimulating cancer-specific T cells, modifying immunosuppressive TMEs, and antibody-mediated therapy targeting CSC markers.

Circulating tumor cells: from new biological insights to clinical practice

The primary reason for high mortality rates among cancer patients is metastasis, where tumor cells migrate through the bloodstream from the original site to other parts of the body. Recent advancements in technology have significantly enhanced our comprehension of the mechanisms behind the bloodborne spread of circulating tumor cells (CTCs). One critical process, DNA methylation, regulates gene expression and chromosome stability, thus maintaining dynamic equilibrium in the body. Global hypomethylation and locus-specific hypermethylation are examples of changes in DNA methylation patterns that are pivotal to carcinogenesis. This comprehensive review first provides an overview of the various processes that contribute to the formation of CTCs, including epithelial-mesenchymal transition (EMT), immune surveillance, and colonization. We then conduct an in-depth analysis of how modifications in DNA methylation within CTCs impact each of these critical stages during CTC dissemination. Furthermore, we explored potential clinical implications of changes in DNA methylation in CTCs for patients with cancer. By understanding these epigenetic modifications, we can gain insights into the metastatic process and identify new biomarkers for early detection, prognosis, and targeted therapies. This review aims to bridge the gap between basic research and clinical application, highlighting the significance of DNA methylation in the context of cancer metastasis and offering new avenues for improving patient outcomes.

Targeting cytokine and chemokine signaling pathways for cancer therapy

Cytokines are critical in regulating immune responses and cellular behavior, playing dual roles in both normal physiology and the pathology of diseases such as cancer. These molecules, including interleukins, interferons, tumor necrosis factors, chemokines, and growth factors like TGF-β, VEGF, and EGF, can promote or inhibit tumor growth, influence the tumor microenvironment, and impact the efficacy of cancer treatments. Recent advances in targeting these pathways have shown promising therapeutic potential, offering new strategies to modulate the immune system, inhibit tumor progression, and overcome resistance to conventional therapies. In this review, we summarized the current understanding and therapeutic implications of targeting cytokine and chemokine signaling pathways in cancer. By exploring the roles of these molecules in tumor biology and the immune response, we highlighted the development of novel therapeutic agents aimed at modulating these pathways to combat cancer. The review elaborated on the dual nature of cytokines as both promoters and suppressors of tumorigenesis, depending on the context, and discussed the challenges and opportunities this presents for therapeutic intervention. We also examined the latest advancements in targeted therapies, including monoclonal antibodies, bispecific antibodies, receptor inhibitors, fusion proteins, engineered cytokine variants, and their impact on tumor growth, metastasis, and the tumor microenvironment. Additionally, we evaluated the potential of combining these targeted therapies with other treatment modalities to overcome resistance and improve patient outcomes. Besides, we also focused on the ongoing research and clinical trials that are pivotal in advancing our understanding and application of cytokine- and chemokine-targeted therapies for cancer patients.

Ramucirumab in combination with pembrolizumab for recurrent or metastatic head and neck squamous cell carcinoma: a single-centre, phase 1/2 trial

BACKGROUND

VEGF, a key mediator of angiogenesis and resistance to immunotherapy, is overexpressed in head and neck squamous cell carcinoma (HNSCC). We aimed to determine the recommended phase 2 dose of ramucirumab, a selective VEGFR2 inhibitor, given with pembrolizumab and the objective response rate of this combination as first-line treatment for recurrent or metastatic HNSCC.

METHODS

In this single-centre, phase 1/2 trial, which was done at Washington University (St Louis, MO, USA), eligible patients were aged 18 years or older with incurable recurrent or metastatic HNSCC and an Eastern Cooperative Oncology Group performance status of 0-2. Patients in phase 2 were required to have had no previous systemic therapy for recurrent or metastatic disease. In a dose de-escalation phase 1 design, patients received ramucirumab (starting dose 10 mg/kg given intravenously) and pembrolizumab (200 mg intravenously) on day 1 of each 21-day cycle. The recommended phase 2 dose of ramucirumab was defined as the highest dose at which one or fewer of three patients had dose-limiting toxicity during cycle one (primary endpoint of phase 1). In a Simon's two-stage phase 2 design, patients received the recommended phase 2 dose of ramucirumab and pembrolizumab. Tumour response (primary endpoint of phase 2) was assessed by Response Evaluation Criteria in Solid Tumours (version 1.1). We hypothesised that there would be an objective response rate of 32% or higher (null ≤13%). Eight or more responses among 33 evaluable patients (those with at least one response assessment) was evidence for activity (80% power; one-sided α=0·05). Analyses were done per protocol. The trial is registered with ClinicalTrials.gov, NCT03650764, and is closed to enrolment.

FINDINGS

Between June 18, 2019, and Feb 11, 2021, three patients enrolled and were treated in phase 1 and 37 patients in phase 2. Median age of all patients was 64 years (IQR 59-72). 36 (90%) of 40 patients were men and four (10%) were women, and 36 (90%) patients were White, three (8%) were Black or African American, and one (3%) was Asian. In phase 1, no dose-limiting toxicity event occurred. The recommended phase 2 dose of ramucirumab was 10 mg/kg. Median follow-up for patients on phase 2 was 14·8 months (IQR 4·9-31·0). In phase 2, 18 (55%; 95% CI 38-70) of 33 evaluable patients had an objective response, including confirmed complete response in 11 patients, confirmed partial response in six patients, and unconfirmed partial response in one patient. The most common grade 3 or worse adverse events were dysphagia (14 [38%] of 37 patients), lung infection (11 [30%]), lymphocyte count decrease (ten [27%]), hypophosphataemia (nine [24%]), and hypertension (eight [22%]). No treatment-related deaths were recorded.

INTERPRETATION

Ramucirumab and pembrolizumab were safe to administer to patients with recurrent or metastatic HNSCC, and the objective response rate with this combination as first-line treatment for recurrent or metastatic HNSCC was favourable. Further studies of ramucirumab and pembrolizumab in patients with recurrent or metastatic HNSCC are warranted.

FUNDING

Lilly and the Joseph Sanchez Foundation.

Incorporation of immunotherapies and nanomedicine to better normalize angiogenesis-based cancer treatment

Neoadjuvant targeting of tumor angiogenesis has been developed and approved for the treatment of malignant tumors. However, vascular disruption leads to tumor hypoxia, which exacerbates the treatment process and causes drug resistance. In addition, successful delivery of therapeutic agents and efficacy of radiotherapy require normal vascular networks and sufficient oxygen, which complete tumor vasculopathy hinders their efficacy. In view of this controversy, an optimal dose of FDA-approved anti-angiogenic agents and combination with other therapies, such as immunotherapy and the use of nanocarrier-mediated targeted therapy, could improve therapeutic regimens, reduce the need for administration of high doses of chemotherapeutic agents and subsequently reduce side effects. Here, we review the mechanism of anti-angiogenic agents, highlight the challenges of existing therapies, and present how the combination of immunotherapies and nanomedicine could improve angiogenesis-based tumor treatment.

Milestones in tumor vascularization and its therapeutic targeting

Research into the mechanisms and manifestations of solid tumor vascularization was launched more than 50 years ago with the proposition and experimental demonstrations that angiogenesis is instrumental for tumor growth and was, therefore, a promising therapeutic target. The biological knowledge and therapeutic insights forthcoming have been remarkable, punctuated by new concepts, many of which were not foreseen in the early decades. This article presents a perspective on tumor vascularization and its therapeutic targeting but does not portray a historical timeline. Rather, we highlight eight conceptual milestones, integrating initial discoveries and recent progress and posing open questions for the future.

The Evolving Scenario of ES-SCLC Management: From Biology to New Cancer Therapeutics

Small cell lung cancer (SCLC) is an aggressive neuroendocrine carcinoma accounting for 15% of lung cancers with dismal survival outcomes. Minimal changes in therapy and prognosis have occurred in SCLC for the past four decades. Recent progress in the treatment of extensive-stage disease (ES-SCLC) has been marked by incorporating immune checkpoint inhibitors (ICIs) into platinum-based chemotherapy, leading to modest improvements. Moreover, few second-line-and-beyond treatment options are currently available. The main limitation for the molecular study of SCLC has been the scarcity of samples, because only very early diseases are treated with surgery and biopsies are not performed when the disease progresses. Despite all these difficulties, in recent years we have come to understand that SCLC is not a homogeneous disease. At the molecular level, in addition to the universal loss of retinoblastoma (RB) and TP53 genes, a recent large molecular study has identified other mutations that could serve as targets for therapy development or patient selection. In recent years, there has also been the identification of new genetic subtypes which have shown us how intertumor heterogeneity exists. Moreover, SCLC can also develop intratumoral heterogeneity linked mainly to the concept of cellular plasticity, mostly due to the development of resistance to therapies. The aim of this review is to quickly present the current standard of care of ES-SCLC, to focus on the molecular landscapes and subtypes of SCLC, subsequently present the most promising therapeutic strategies under investigation, and finally recap the future directions of ongoing clinical trials for this aggressive disease which still remains a challenge.

Blocking the angiopoietin-2-dependent integrin β-1 signaling axis abrogates small cell lung cancer invasion and metastasis

Small cell lung cancer (SCLC) is the most aggressive lung cancer entity with an extremely limited therapeutic outcome. Most patients are diagnosed at an extensive stage. However, the molecular mechanisms driving SCLC invasion and metastasis remain largely elusive. We used an autochthonous SCLC mouse model and matched samples from patients with primary and metastatic SCLC to investigate the molecular characteristics of tumor metastasis. We demonstrate that tumor cell invasion and liver metastasis in SCLC are triggered by an Angiopoietin-2 (ANG-2)/Integrin β-1-dependent pathway in tumor cells, mediated by focal adhesion kinase/Src kinase signaling. Strikingly, CRISPR-Cas9 KO of Integrin β-1 or blocking Integrin β-1 signaling by an anti-ANG-2 treatment abrogates liver metastasis formation in vivo. Interestingly, analysis of a unique collection of matched samples from patients with primary and metastatic SCLC confirmed a strong increase of Integrin β-1 in liver metastasis in comparison with the primary tumor. We further show that ANG-2 blockade combined with PD-1-targeted by anti-PD-1 treatment displays synergistic treatment effects in SCLC. Together, our data demonstrate a fundamental role of ANG-2/Integrin β-1 signaling in SCLC cells for tumor cell invasion and liver metastasis and provide a potentially new effective treatment strategy for patients with SCLC.

An innovative antibody fusion protein targeting PD-L1, VEGF and TGF-β with enhanced antitumor efficacies

Immunosuppressive pathways in the tumor microenvironment (TME) are inextricably linked to tumor progression. Mono-therapeutics of immune checkpoint inhibitors (ICIs, e.g. antibodies against programmed cell death protein-1/programmed cell death ligand-1, PD-1/PD-L1) is prone to immune escape while combination therapeutics tends to cause high toxicity and side effects. Therefore, using multi-functional molecules to target multiple pathways simultaneously is becoming a new strategy for cancer therapies. Here, we developed a trifunctional fusion protein, DR30206, composed of Bevacizumab (an antibody against VEGF), and a variable domain of heavy chain of heavy chain antibody (VHH) against PD-L1 and the extracellular domain (ECD) protein of TGF-β receptor II (TGF-β RII), which are fused to the N- and C-terminus of Bevacizumab, respectively. The original intention of DR30206 design was to enhance the immune responses pairs by targeting PD-L1 while inhibiting VEGF and TGF-β in the TME. Our data demonstrated that DR30206 exhibits high antigen-binding affinities and efficient blocking capabilities, the principal drivers of efficacy in antibody therapy. Furthermore, the capability of eliciting antibody-dependent cellular cytotoxicity (ADCC) and mixed lymphocyte reaction (MLR) provides a greater possibility to enhance the immune response. Finally, in vivo experiments showed that the antitumor activity of DR30206 was superior to those of monoclonal antibody of PD-L1 or VEGF, PD-L1 and TGF-β bispecific antibody or the combination inhibition of PD-L1 and VEGF. Our findings suggest there is a great potential for DR30206 to become a therapeutic for the treatment of multiple cancer types, especially lung cancer, colon adenocarcinoma and breast carcinoma.

Co-targeting CD47 and VEGF elicited potent anti-tumor effects in gastric cancer

BACKGROUND

CD47, serving as an intrinsic immune checkpoint, has demonstrated efficacy as an anti-tumor target in hematologic malignancies. Nevertheless, the clinical relevance of CD47 in gastric cancer and its potential as a therapeutic target remains unclear.

METHODS

The expression of CD47 in clinical gastric cancer tissues was assessed using immunohistochemistry and Western blot. Patient-derived cells were obtained from gastric cancer tissues and co-cultured with macrophages derived from human peripheral blood mononuclear cells. Flow cytometry analyses were employed to evaluate the rate of phagocytosis. Humanized patient-derived xenografts (Hu-PDXs) models were established to assess the efficacy of anti-CD47 immunotherapy or the combination of anti-CD47 and anti-VEGF therapy in treating gastric cancer. The infiltrated immune cells in the xenograft were analyzed by immunohistochemistry.

RESULTS

In this study, we have substantiated the high expression of CD47 in gastric cancer tissues, establishing a strong association with unfavorable prognosis. Through the utilization of SIRPα-Fc to target CD47, we have effectively enhanced macrophage phagocytosis of PDCs in vitro and impeded the growth of Hu-PDXs. It is noteworthy that anti-CD47 immunotherapy has been observed to sustain tumor angiogenic vasculature, with a positive correlation between the expression of VEGF and CD47 in gastric cancer. Furthermore, the successful implementation of anti-angiogenic treatment has further augmented the anti-tumor efficacy of anti-CD47 therapy. In addition, the potent suppression of tumor growth, prevention of cancer recurrence after surgery, and significant prolongation of overall survival in Hu-PDX models can be achieved through the simultaneous targeting of CD47 and VEGF using the bispecific fusion protein SIRPα-VEGFR1 or by combining the two single-targeted agents.

CONCLUSIONS

Our preclinical studies collectively offer substantiation that CD47 holds promise as a prospective target for gastric cancer, while also highlighting the potential of anti-angiogenic therapy to enhance tumor responsiveness to anti-CD47 immunotherapy.

Benefits and risks of PD-1/PD-L1 inhibitors for recurrent small cell lung cancer: A systematic review and meta-analysis

The development of immune checkpoint inhibitors(ICIs) has revolutionized the progress of solid tumors. Ongoing clinical trials are exploring the use of checkpoint inhibitors in recurrent small-cell lung cancer and achieving specific results. Although studies have been conducted to systematically review this issue, we conducted this single-arm meta-analysis in light of the emergence of several new clinical studies. In total, 854 individuals from 11 clinical investigations were enrolled in this single-arm meta-analysis. Median progression-free survival, median overall survival, and objective response rate were 1.65 months, 6.83 months, and 20.5%, respectively, according to pooled analyses. The best treatment regimen in the subgroup analysis was a dual checkpoint inhibitor combined with other treatments, and the drug that worked well for treatment was pembrolizumab. The benefit of programmed death 1/programmed cell death-ligand 1(PD-1/PD-L1) inhibitors alone is limited, and their combination with other therapies is a promising treatment option. Among PD-1/PD-L1 inhibitors, pembrolizumab is the recommended drug.

Reprogramming of VEGF-mediated extracellular matrix changes through autocrine signaling

Vascular endothelial growth factor (VEGF) plays key roles in angiogenesis, vasculogenesis, and wound healing. In cancers, including triple negative breast cancer (TNBC), VEGF has been associated with increased invasion and metastasis, processes that require cancer cells to traverse through the extracellular matrix (ECM) and establish angiogenesis at distant sites. To further understand the role of VEGF in modifying the ECM, we characterized VEGF-mediated changes in the ECM of tumors derived from TNBC MDA-MB-231 cells engineered to overexpress VEGF. We established that increased VEGF expression by these cells resulted in tumors with reduced collagen 1 (Col1) fibers, fibronectin, and hyaluronan. Molecular characterization of tumors identified an increase of MMP1, uPAR, and LOX, and a decrease of MMP2, and ADAMTS1. α-SMA, a marker of cancer associated fibroblasts (CAFs), increased, and FAP-α, a marker of a subset of CAFs associated with immune suppression, decreased with VEGF overexpression. Analysis of human data from The Cancer Genome Atlas Program confirmed mRNA differences for several molecules when comparing TNBC with high and low VEGF expression. We additionally characterized enzymatic changes induced by VEGF overexpression in three different cancer cell lines that clearly identified autocrine-mediated changes, specifically uPAR, in these enzymes. Unlike the increase of Col1 fibers and fibronectin mediated by VEGF during wound healing, in the TNBC model, VEGF significantly reduced key protein components of the ECM. These results further expand our understanding of the role of VEGF in cancer progression and identify potential ECM-related targets to disrupt this progression.

Vascular normalization: reshaping the tumor microenvironment and augmenting antitumor immunity for ovarian cancer

Ovarian cancer remains a challenging disease with limited treatment options and poor prognosis. The tumor microenvironment (TME) plays a crucial role in tumor growth, progression, and therapy response. One characteristic feature of the TME is the abnormal tumor vasculature, which is associated with inadequate blood perfusion, hypoxia, and immune evasion. Vascular normalization, a therapeutic strategy aiming to rectify the abnormal tumor vasculature, has emerged as a promising approach to reshape the TME, enhance antitumor immunity, and synergize with immunotherapy in ovarian cancer. This review paper provides a comprehensive overview of vascular normalization and its potential implications in ovarian cancer. In this review, we summarize the intricate interplay between anti-angiogenesis and immune modulation, as well as ICI combined with anti-angiogenesis therapy in ovarian cancer. The compelling evidence discussed in this review contributes to the growing body of knowledge supporting the utilization of combination therapy as a promising treatment paradigm for ovarian cancer, paving the way for further clinical development and optimization of this therapeutic approach.

Molecular and biological factors in the prognosis of head and neck squamous cell cancer

The objective of the review is to summarize available literary data on the role and prognostic value of molecular biological markers p53, UBE2C, CD147, STAT3, VEGF in the carcinogenesis of head and neck squamous cell carcinoma (HNSCC). To date, researches have been studying HNSCC molecular and genetic characteristics and obtaining information about new molecular biological markers that have different functional significance in tumor progression. This review presents current data on protein molecules involved in the HNSCC development, as well as in the formation of drug resistance mechanisms in tumors. The considered markers can be used not only for prognosis but also for developing a new approach to treatment, including patients resistant to therapy or recurrent HNSCC. However, the introduction of these markers into practice requires further examination of their functions and larger-scale studies.

Tyrosine kinase and immune checkpoints inhibitors in favorable risk metastatic renal cell carcinoma: Trick or treat?

Over the past decade, the management of metastatic renal cell carcinoma (RCC) has undergone rapid evolution, culminating in a significant improvement in prognosis with frontline immunotherapy. RCC is a highly immunogenic and pro-angiogenic cancer, and mounting evidence has established the immunosuppressive effects of pro-angiogenic factors on the host's immune system. Anti-angiogenic agents such as tyrosine kinase inhibitors (TKIs) and bevacizumab, which obstruct the vascular endothelial growth factor pathway, have demonstrated the potential to enhance antitumor activity and improve the efficacy of immune checkpoint inhibitors (ICIs). Consequently, various combinations of TKIs and ICIs have been assessed and are currently considered the preferred regimens for all metastatic RCC patients, regardless of their prognostic risk score. Nevertheless, some inquiries have arisen within the medical community, as metastatic RCC patients with favorable risk scores who received ICIs and TKIs in combination showed no statistically significant advantage in overall survival compared to those treated with sunitinib alone. Considering these concerns, this review aims to elucidate the rationale behind TKI and ICI combination therapies, provide a summary of current first-line metastatic RCC combinations approved for use, with a focus on favorable-risk patients, and outline present challenges and future perspectives in this context.

AK112, a novel PD-1/VEGF bispecific antibody, in combination with chemotherapy in patients with advanced non-small cell lung cancer (NSCLC): an open-label, multicenter, phase II trial

Background

Inhibiting vascular endothelial growth factor (VEGF) function can improve the efficacy of immunotherapy by modulating the tumor immune microenvironment. AK112 is the first-in-class humanized IgG1 bispecific antibody targeting programmed death-1 (PD-1) and VEGF. This study aimed to evaluate the efficacy and safety of AK112 combined with chemotherapy in patients with advanced non-small cell lung cancer (NSCLC).

Methods

This open-label, multicenter, phase II clinical trial was conducted in 11 hospitals in China. Eligible participants were adults aged 18-75 years with locally advanced or metastatic NSCLC, an Eastern Cooperative Oncology Group performance status of 0 or 1, at least one measurable lesion, and an estimated life expectancy of at least 3 months. The participants were categorized into three cohorts based on prior therapy and functional genomic alterations. Patients in cohort 1 were previously untreated advanced NSCLC, had no epidermal growth factor receptor (EGFR) or anaplastic lymphoma kinase (ALK) gene modifications, and received AK112 combined with pemetrexed (500 mg/m2) for non-squamous (non-sq)-NSCLC or paclitaxel (175 mg/m2) for sq-NSCLC plus carboplatin (area under the curve of 5 mg/mL per min) for four cycles, followed by AK112 with pemetrexed for non-sq-NSCLC and AK112 alone for sq-NSCLC as maintenance therapy. The participants in cohort 2 had advanced NSCLC with EGFR-sensitive mutations, failed previous EGFR-tyrosine kinase inhibitor (TKI) therapy, and received pemetrexed plus AK112 and carboplatin for four cycles, followed by pemetrexed plus AK112 as maintenance therapy. The participants in cohort 3 had advanced NSCLC who failed systemic platinum-based chemotherapy and anti-PD-1/programmed death-ligand 1 (PD-L1) treatments and received AK112 plus docetaxel (75 mg/m2). Two dosages of AK112 (10 or 20 mg/kg) were examined in each cohort, and the drug was administered intravenously on day 1 of each 3-week treatment cycle. The primary endpoints were the investigator-assessed objective response rate (ORR) and safety. This study was registered with ClinicalTrials.gov (NCT04736823).

Findings

Eighty-three patients were enrolled from February 2021 to August 2022 and received the study treatment. Cohorts 1, 2, and 3 had 44, 19, and 20 patients, respectively. The confirmed ORR was 53.5% (23/43) [95% CI, 36.9-67.1], 68.4% (13/19) [95% CI, 43.4-87.4], and 40.0% (8/20) [95% CI, 19.1-63.9] in cohorts 1, 2, and 3, respectively. In cohort 1, the median PFS was not reached, and the 12-month PFS rate was 59.1%. In cohorts 2 and 3, the median PFS were 8.5 [95% CI, 5.5-NE] and 7.5 [95% CI, 2.3-NE] months, and the 12-month PFS rates were 35.5% and 44.5%, respectively. The most common grade ≥3 treatment-related adverse events were decreased white blood cell count [7 (8.4%)], neutropenia [5 (6.0%)], thrombocytopenia [2 (2.4%)], anemia [4 (4.8%)], and myelosuppression [2 (2.4%)].

Interpretation

AK112 plus platinum-doublet showed promising antitumor activity and safety not only in first-line treatment of advanced NSCLC patients without driver mutation but also in patients with EGFR-functional mutation who failed previous EGFR-TKI therapy and advanced NSCLC patients who failed prior systemic platinum-based chemotherapy and PD-1/PD-L1 inhibitor treatments, suggesting a valuable potential new treatment option for this patient population.

Funding

Akeso Biopharma, Inc., Zhongshan, China, and National Natural Science Foundation of China.

Biomarkers for Immune Checkpoint Inhibitors in Renal Cell Carcinoma

Immune checkpoint inhibitor (ICI) therapy has revolutionized renal cell carcinoma treatment. Patients previously thought to be palliative now occasionally achieve complete cures from ICI. However, since immunotherapies stimulate the immune system to induce anti-tumor immunity, they often lead to adverse autoimmunity. Furthermore, some patients receive no benefit from ICI, thereby unnecessarily risking adverse events. In many tumor types, PD-L1 expression levels, immune infiltration, and tumor mutation burden predict the response to ICI and help inform clinical decision making to better target ICI to patients most likely to experience benefits. Unfortunately, renal cell carcinoma is an outlier, as these biomarkers fail to discriminate between positive and negative responses to ICI therapy. Emerging biomarkers such as gene expression profiles and the loss of pro-angiogenic proteins VHL and PBRM-1 show promise for identifying renal cell carcinoma cases likely to respond to ICI. This review provides an overview of the mechanistic underpinnings of different biomarkers and describes the theoretical rationale for their use. We discuss the effectiveness of each biomarker in renal cell carcinoma and other cancer types, and we introduce novel biomarkers that have demonstrated some promise in clinical trials.

Developing a dual VEGF/PDL1 inhibitor based on high-affinity scFv heterodimers as an anti-cancer therapeutic strategy

Cancer progression is enhanced by the interaction of programmed death-ligand 1 (PDL1), which is associated with inhibition of the immune response against tumors, and vascular endothelial growth factor (VEGF), which inhibits immune cell activity while inducing angiogenesis and proliferation of cancer cells. Dual inhibition of PDL1 and VEGF may therefore confer a synergistic anti-cancer therapeutic effect. We present a novel strategy for developing a therapeutic that simultaneously binds and inhibits both PDL1 and VEGF. We generated a bi-specific protein, designated DuRan-Bis, comprising a single chain variable fragment (scFv)-based inhibitor of PDL1 fused to an scFv-based inhibitor of VEGF, with the latter being attached to an Fc fragment. We found that DuRan-Bis binds to both PDL1 and VEGF with high affinity. Compared to treatments with mono-specific proteins, alone or in combination, the DuRan-Bis chimera showed superior inhibition of the proliferation of glioblastoma cells. In comparison to treatment with immune cells alone, a combination of immune cells with DuRan-Bis decreased the viability of head and neck cancer cells. To the best of our knowledge, this study is the first to use a single polypeptide chain scFv-scFv-Fc scaffold for engineering a high-affinity bi-specific inhibitor of PDL1 and VEGF.

Camrelizumab as a novel third or post-third-line treatment strategy in small cell lung cancer: a retrospective study of 12 patients

Background

Small cell lung cancer (SCLC) constitutes 15% of all lung cancer cases, with a comparatively low survival rate. The advent of immune checkpoint inhibitors (ICIs) has provided new alternatives for treating SCLC. However, the effectiveness of camrelizumab in the treatment of SCLC remains unclear. This retrospective case series was designed to investigate the efficacy and safety of camrelizumab in SCLC patients.

Methods

The study enrolled SCLC patients recorded as having received more than one cycle of camrelizumab in the electronic medical record system. Data related to clinical and survival times were collected and statistically analyzed.

Results

From August 2019 to December 2021, the study enrolled 12 SCLC patients. The objective response rate was 41.7% (95% confidence interval [CI]: 15.2%-72.3%). The disease control rate was 83.3% (95% CI: 51.6%-97.9%). The median progression-free survival (PFS) for all patients was 4.0 months. Notably, the median PFS of patients in third- or post-third-line subgroups was 7 months (95% CI: 1.12-12.88 months). The median overall survival (OS) for all eligible patients was 10.0 months (95% CI: 7.35-12.65 months), with a 1-year survival rate of 25%. Notably, the OS of patients treated with third- or post-third-line therapy was 5-34 months, with a 1-year survival rate of 75%. The two most prevalent non-hematological adverse events associated with the immune response were pneumonitis (44.4%) and reactive cutaneous capillary endothelial proliferation (44.4%). One patient experienced an exacerbation of preexisting diabetes and reached grade 3 hyperglycemia. There were no grade 4/5 immune-related adverse events.

Conclusion

This case series highlights the potential benefits and safety concerns of camrelizumab in SCLC patients. These findings suggest a possible strategy for third- and post-third-line treatments of SCLC. However, the conclusion is limited due to the study's retrospective nature and small sample size. Therefore, large-scale randomized controlled studies are needed to determine its efficacy.

Histone modifications in drug-resistant cancers: From a cancer stem cell and immune evasion perspective

The development and immune evasion of cancer stem cells (CSCs) limit the efficacy of currently available anticancer therapies. Recent studies have shown that epigenetic reprogramming regulates the expression of characteristic marker proteins and tumor plasticity associated with cancer cell survival and metastasis in CSCs. CSCs also possess unique mechanisms to evade external attacks by immune cells. Hence, the development of new strategies to restore dysregulated histone modifications to overcome cancer resistance to chemotherapy and immunotherapy has recently attracted attention. Restoring abnormal histone modifications can be an effective anticancer strategy to increase the therapeutic effect of conventional chemotherapeutic and immunotherapeutic drugs by weakening CSCs or by rendering them in a naïve state with increased sensitivity to immune responses. In this review, we summarize recent findings regarding the role of histone modifiers in the development of drug-resistant cancer cells from the perspectives of CSCs and immune evasion. In addition, we discuss attempts to combine currently available histone modification inhibitors with conventional chemotherapy or immunotherapy.

Reprogramming the immunosuppressive tumor microenvironment: exploiting angiogenesis and thrombosis to enhance immunotherapy

This review focuses on the immunosuppressive effects of tumor angiogenesis and coagulation on the tumor microenvironment (TME). We summarize previous research efforts leveraging these observations and targeting these processes to enhance immunotherapy outcomes. Clinical trials have documented improved outcomes when combining anti-angiogenic agents and immunotherapy. However, their overall survival benefit over conventional therapy remains limited and certain tumors exhibit poor response to anti-angiogenic therapy. Additionally, whilst preclinical studies have shown several components of the tumor coagulome to curb effective anti-tumor immune responses, the clinical studies reporting combinations of anticoagulants with immunotherapies have demonstrated variable treatment outcomes. By reviewing the current state of the literature on this topic, we address the key questions and future directions in the field, the answers of which are crucial for developing effective strategies to reprogram the TME in order to further the field of cancer immunotherapy.

Transarterial chemoembolization plus immune checkpoint inhibitor as postoperative adjuvant therapy for hepatocellular carcinoma with portal vein tumor thrombus: A multicenter cohort study

PURPOSE

This study aimed to assess the efficacy and safety of postoperative adjuvant transarterial chemoembolization (PA-TACE) plus immune checkpoint inhibitor (ICI) for hepatocellular carcinoma (HCC) with portal vein tumor thrombus (PVTT).

PATIENTS AND METHODS

This study was conducted on three centers from June 2018 to December 2020. Patients were divided into the PA-TACE (n = 48) and PA-TACE plus ICI groups (n = 42). The recurrence-free survival (RFS) and overall survival (OS) curves were depicted by Kaplan-Meier method, and the differences between the two groups were compared using log-rank test. Univariate and multivariate Cox analyses were performed to identify independent risk factors for RFS and OS. Adverse events (AEs) were assessed according to the Common Terminology Criteria for AEs (CTCAE) version 5.0.

RESULTS

The median RFS of the PA-TACE plus ICI group was significantly longer than the PA-TACE group (12.76 months vs. 8.11 months; P = 0.038). The median OS of the PA-TACE plus ICI group was also significanfly better than the PA-TACE group (24.5 months vs. 19.1 months; P = 0.032). PA-TACE plus ICI treatment was an independent prognostic factor for RFS (HR: 0.54, 95% CI: 0.32-0.9, P = 0.019) and OS (HR: 0.47, 95% CI: 0.26-0.86, P = 0.014). Only one patient experienced grade ≥3 immune-related AEs in the PA-TACE plus ICI group.

CONCLUSIONS

PA-TACE plus ICI treatment had better efficacy in preventing recurrence and prolonging survival than PA-TACE alone for HCC patients with PVTT after R0 resection. This novel treatment modality may be an appropriate option for HCC with PVTT.

Targeting angiogenesis in oncology, ophthalmology and beyond

Angiogenesis is an essential process in normal development and in adult physiology, but can be disrupted in numerous diseases. The concept of targeting angiogenesis for treating diseases was proposed more than 50 years ago, and the first two drugs targeting vascular endothelial growth factor (VEGF), bevacizumab and pegaptanib, were approved in 2004 for the treatment of cancer and neovascular ophthalmic diseases, respectively. Since then, nearly 20 years of clinical experience with anti-angiogenic drugs (AADs) have demonstrated the importance of this therapeutic modality for these disorders. However, there is a need to improve clinical outcomes by enhancing therapeutic efficacy, overcoming drug resistance, defining surrogate markers, combining with other drugs and developing the next generation of therapeutics. In this Review, we examine emerging new targets, the development of new drugs and challenging issues such as the mode of action of AADs and elucidating mechanisms underlying clinical benefits; we also discuss possible future directions of the field.

Adverse events of PD-(L)1 inhibitors plus anti-VEGF(R) agents compared with PD-(L)1 inhibitors alone for cancer patients: a systematic review and meta-analysis

Background: Anti-PD-(L)1 antibody monotherapy or in combination with VEGF(R) blockade has been applied widely for cancer treatment. Whether combination therapy increases irAEs still remains controversial. Methods: A systematic review and meta-analysis comparing PD-(L)1 and VEGF(R) blockade combination therapy with PD-(L)1 inhibitors alone was performed. Phase II or III randomized clinical trials reporting irAEs or trAEs were included. The protocol was registered with PROSPERO, CRD42021287603. Results: Overall, 77 articles were included in the meta-analysis. A total of 31 studies involving 8,638 participants were pooled and an incidence for PD-(L)1 inhibitor monotherapy with any grade and grade ≥3 irAEs of 0.25 (0.20, 0.32) and 0.06 (0.05, 0.07), respectively, were reported. Two studies with 863 participants pooled for PD-(L)1 and VEGF(R) blockade showed that an incidence of any grade and grade ≥3 irAEs were 0.47 (0.30, 0.65) and 0.11 (0.08, 0.16), respectively. Regarding pairwise comparisons for irAEs, only one study was included, indicating no significant difference between the two regimens in terms of colitis, hyperthyroidism, and hypothyroidism for any grade and grade ≥3, while there was a trend of higher incidence for any grade hyperthyroidism under the combination therapy. The incidence of reactive cutaneous capillary endothelial proliferation (RCCEP) was as high as 0.80 under camrelizumab monotherapy. Conclusion: Total incidences of any grade and grade ≥3 irAEs were higher in the combination treatment group. Direct comparisons indicated no significant difference between the two regimens for any grade and grade ≥3 specific irAEs. RCCEP and thyroid disorders need to be paid attention to clinically. Moreover, trials with direct comparisons are needed and the safety profiles of the two regimens should be further explored. Exploration of the mechanism of action and regulatory management of adverse events should be enhanced. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=287603, identifier CRD42021287603.

Acute inflammatory reaction during anti-angiogenesis therapy combined with immunotherapy as a possible indicator of the therapeutic effect: Three case reports and literature review

The posterior line treatment of unresectable advanced or metastatic gastrointestinal (GI) tumors has always been a challenging point. In particular, for patients with microsatellite stable (MSS)/mismatch repair proficient (pMMR) 0GI tumors, the difficulty of treatment is exacerbated due to their insensitivity to immune drugs. Accordingly, finding a new comprehensive therapy to improve the treatment effect is urgent. In this study, we report the treatment histories of three patients with MSS/pMMR GI tumors who achieved satisfactory effects by using a comprehensive treatment regimen of apatinib combined with camrelizumab and TAS-102 after the failure of first- or second-line regimens. The specific contents of the treatment plan were as follows: apatinib (500 mg/d) was administered orally for 10 days, followed by camrelizumab (200 mg, ivgtt, day 1, 14 days/cycle) and TAS-102 (20 mg, oral, days 1-21, 28 days/cycle). Apatinib (500 mg/d) was maintained during treatment. Subsequently, we discuss the possible mechanism of this combination and review the relevant literature, and introduce clinical trials on anti-angiogenesis therapy combined with immunotherapy.

An unusual case of immune-related gastritis in one patient receiving toripalimab therapy

PD-1 inhibitors contribute to immune response against malignancies. These drugs also result in serial side effects. Here the authors report a case of immune-related gastritis induced by PD-1 inhibitor. A female with metastatic lung cancer developed severe epigastric pain and acid reflux during treatment with toripalimab. She underwent several gastroscopies, which showed progressively worse gastritis. After discontinuing toripalimab, those symptoms were resolved. This rare report highlights gastritis associated with toripalimab, describes the symptoms and histology features and records the progression of this side effect and the corresponding treatment. Based on the improvement after toripalimab withdrawal, the authors believed that she had autoimmune gastritis caused by toripalimab. This case reminds us that correct diagnosis and proper management are critical to patients undergoing treatment with PD-1 inhibitors.

Emerging Strategies for the Treatment of Small Cell Lung Cancer: A Review

Importance

Small cell lung cancer (SCLC) is an aggressive disease that is characterized by rapid growth and the early development of metastases. Patients typically respond to initial chemotherapy but quickly experience relapse, resulting in a poor long-term outcome. Therapeutic innovations that substantially improve survival have historically been limited, and reliable, predictive biomarkers are lacking.

Observations

This review examines the biologic characteristics of SCLC, the current treatment landscape, and ongoing efforts to identify novel therapeutic targets. Ongoing research has advanced the understanding of molecular categories and the immunologic microenvironment of SCLC, which in turn has helped improve disease classification and staging. Recently, immunotherapy-based regimens have become available for the management of SCLC, with 2 programmed cell death 1 ligand 1 inhibitors approved in combination with chemotherapy for first-line treatment of extensive-stage disease. For second-line treatment, a novel alkylating agent, lurbinectedin, which inhibits oncogenic transcription, has been approved for use in patients with metastatic SCLC. Furthermore, a wide variety of therapies and innovative combination regimens are being continuously evaluated. Potential therapeutic strategies, including aurora kinase A inhibitors, polyadenosine diphosphate-ribose polymerase inhibitors, ataxia telangiectasia and Rad3-related inhibitors, cyclin-dependent kinase 7 inhibitors, delta-like protein 3 agents, antiganglioside agents, CD47 inhibitors, and lysine-specific histone demethylase 1a inhibitors, are also being examined.

Conclusions and Relevance

Therapeutic optimization of SCLC remains a challenge, but recent trial results and drug approvals are encouraging. Advances in research have revealed critical information regarding biologic characteristics of the disease, which may lead to the identification of vulnerabilities and the development of new therapies. Further research focused on identifying biomarkers and evaluating innovative therapies will be paramount to improving treatment outcomes for patients with SCLC.

Tumor Vasculature as an Emerging Pharmacological Target to Promote Anti-Tumor Immunity

Tumor vasculature abnormality creates a microenvironment that is not suitable for anti-tumor immune response and thereby induces resistance to immunotherapy. Remodeling of dysfunctional tumor blood vessels by anti-angiogenic approaches, known as vascular normalization, reshapes the tumor microenvironment toward an immune-favorable one and improves the effectiveness of immunotherapy. The tumor vasculature serves as a potential pharmacological target with the capacity of promoting an anti-tumor immune response. In this review, the molecular mechanisms involved in tumor vascular microenvironment-modulated immune reactions are summarized. In addition, the evidence of pre-clinical and clinical studies for the combined targeting of pro-angiogenic signaling and immune checkpoint molecules with therapeutic potential are highlighted. The heterogeneity of endothelial cells in tumors that regulate tissue-specific immune responses is also discussed. The crosstalk between tumor endothelial cells and immune cells in individual tissues is postulated to have a unique molecular signature and may be considered as a potential target for the development of new immunotherapeutic approaches.

Cross-talk between cancer stem cells and immune cells: potential therapeutic targets in the tumor immune microenvironment

Ongoing research has revealed that the existence of cancer stem cells (CSCs) is one of the biggest obstacles in the current cancer therapy. CSCs make an influential function in tumor progression, recurrence and chemoresistance due to their typical stemness characteristics. CSCs are preferentially distributed in niches, and those niche sites exhibit characteristics typical of the tumor microenvironment (TME). The complex interactions between CSCs and TME illustrate these synergistic effects. The phenotypic heterogeneity within CSCs and the spatial interactions with the surrounding tumor microenvironment led to increased therapeutic challenges. CSCs interact with immune cells to protect themselves against immune clearance by exploiting the immunosuppressive function of multiple immune checkpoint molecules. CSCs also can protect themselves against immune surveillance by excreting extracellular vesicles (EVs), growth factors, metabolites and cytokines into the TME, thereby modulating the composition of the TME. Therefore, these interactions are also being considered for the therapeutic development of anti-tumor agents. We discuss here the immune molecular mechanisms of CSCs and comprehensively review the interplay between CSCs and the immune system. Thus, studies on this topic seem to provide novel ideas for reinvigorating therapeutic approaches to cancer.

The Combination of Immune Checkpoint Blockade with Tumor Vessel Normalization as a Promising Therapeutic Strategy for Breast Cancer: An Overview of Preclinical and Clinical Studies

Immune checkpoint inhibitors (ICIs) have a modest clinical activity when administered as monotherapy against breast cancer (BC), the most common malignancy in women. Novel combinatorial strategies are currently being investigated to overcome resistance to ICIs and promote antitumor immune responses in a greater proportion of BC patients. Recent studies have shown that the BC abnormal vasculature is associated with immune suppression in patients, and hampers both drug delivery and immune effector cell trafficking to tumor nests. Thus, strategies directed at normalizing (i.e., at remodeling and stabilizing) the immature, abnormal tumor vessels are receiving much attention. In particular, the combination of ICIs with tumor vessel normalizing agents is thought to hold great promise for the treatment of BC patients. Indeed, a compelling body of evidence indicates that the addition of low doses of antiangiogenic drugs to ICIs substantially improves antitumor immunity. In this review, we outline the impact that the reciprocal interactions occurring between tumor angiogenesis and immune cells have on the immune evasion and clinical progression of BC. In addition, we overview preclinical and clinical studies that are presently evaluating the therapeutic effectiveness of combining ICIs with antiangiogenic drugs in BC patients.

Tim-3 Coordinates Macrophage-Trophoblast Crosstalk via Angiogenic Growth Factors to Promote Pregnancy Maintenance

T-cell immunoglobulin mucin-3 (Tim-3) is an important checkpoint that induces maternal-fetal tolerance in pregnancy. Macrophages (Mφs) play essential roles in maintaining maternal-fetal tolerance, remodeling spiral arteries, and regulating trophoblast biological behaviors. In the present study, the formation of the labyrinth zone showed striking defects in pregnant mice treated with Tim-3 neutralizing antibodies. The adoptive transfer of Tim-3⁺Mφs, rather than Tim-3^-Mφs, reversed the murine placental dysplasia resulting from Mφ depletion. With the higher production of angiogenic growth factors (AGFs, including PDGF-AA, TGF-α, and VEGF), Tim-3⁺dMφs were more beneficial in promoting the invasion and tube formation ability of trophoblasts. The blockade of AGFs in Tim-3⁺Mφs led to the narrowing of the labyrinthine layer of the placenta, compromising maternal-fetal tolerance, and increasing the risk of fetal loss. Meanwhile, the AGFs-treated Tim-3^-Mφs could resolve the placental dysplasia and fetal loss resulting from Mφ depletion. These findings emphasized the vital roles of Tim-3 in coordinating Mφs-extravillous trophoblasts interaction via AGFs to promote pregnancy maintenance and in extending the role of checkpoint signaling in placental development. The results obtained in our study also firmly demonstrated that careful consideration of reproductive safety should be taken when selecting immune checkpoint and AGF blockade therapies in real-world clinical care.

Molecular Mechanisms and Future Implications of VEGF/VEGFR in Cancer Therapy

Angiogenesis, the sprouting of new blood vessels from existing vessels, is one of six known mechanisms employed by solid tumors to recruit blood vessels necessary for their initiation, growth, and metastatic spread. The vascular network within the tumor facilitates the transport of nutrients, oxygen, and immune cells and is regulated by pro- and anti-angiogenic factors. Nearly four decades ago, VEGF was identified as a critical factor promoting vascular permeability and angiogenesis, followed by identification of VEGF family ligands and their receptors (VEGFR). Since then, over a dozen drugs targeting the VEGF/VEGFR pathway have been approved for approximately 20 solid tumor types, usually in combination with other therapies. Initially designed to starve tumors, these agents transiently "normalize" tumor vessels in preclinical and clinical studies, and in the clinic, increased tumor blood perfusion or oxygenation in response to these agents is associated with improved outcomes. Nevertheless, the survival benefit has been modest in most tumor types, and there are currently no biomarkers in routine clinical use for identifying which patients are most likely to benefit from treatment. However, the ability of these agents to reprogram the immunosuppressive tumor microenvironment into an immunostimulatory milieu has rekindled interest and has led to the FDA approval of seven different combinations of VEGF/VEGFR pathway inhibitors with immune checkpoint blockers for many solid tumors in the past 3 years. In this review, we discuss our understanding of the mechanisms of response and resistance to blocking VEGF/VEGFR, and potential strategies to develop more effective therapeutic approaches.

T lymphocyte cell: A pivotal player in lung cancer

Lung cancer is responsible for the leading cause of cancer-related death worldwide, which lacks effective therapies. In recent years, accumulating evidence on the understanding of the antitumor activity of the immune system has demonstrated that immunotherapy is one of the powerful alternatives in lung cancer therapy. T cells are the core of cellular immunotherapy, which are critical for tumorigenesis and the treatment of lung cancer. Based on the different expressions of surface molecules and functional points, T cells can be subdivided into regulatory T cells, T helper cells, cytotoxic T lymphocytes, and other unconventional T cells, including γδ T cells, nature killer T cells and mucosal-associated invariant T cells. Advances in our understanding of T cells' functional mechanism will lead to a number of clinical trials on the discovery and development of new treatment strategies. Thus, we summarize the biological functions and regulations of T cells on tumorigenesis, progression, metastasis, and prognosis in lung cancer. Furthermore, we discuss the current advancements of technologies and potentials of T-cell-oriented therapeutic targets for lung cancer.

Immunotherapy for extensive-stage small-cell lung cancer: current landscape and future perspectives

Small-cell lung cancer (SCLC) is a fatal subtype of lung cancer characterized by high aggressiveness, poor prognosis, and limited treatment options. For the first time in more than three decades, it has been demonstrated that the addition of immunotherapy to chemotherapy improved the survival of patients with extensive-stage SCLC, thereby immunotherapy plus chemotherapy established a new standard of first-line treatment. However, it is important to improve the curative effect of immunotherapy on SCLC and identify the patients who could benefit from such treatment. In this article, we review the current status of the first-line immunotherapy, the strategies to improve the efficacy of immunotherapy and the discovery of potential predictive biomarkers of immunotherapy for SCLC.

Recent progress in cancer immunotherapy: Overview of current status and challenges

Cancer treatment is presently one of the most important challenges in medical science. Surgery, chemotherapy, radiotherapy, or combining these methods is used to eliminate the tumor. Hormone therapy, bone marrow transplantation, stem cell therapy as well as immunotherapy are other well-known therapeutic modalities. Immunotherapy, as the most important complementary method, uses the immune system for treating cancer followed by surgery, chemotherapy, and radiotherapy. This method is systematically used to prevent malignancies development mainly via potentiating antitumor immune cells activation and conversely compromising their exhaustion with the lowest negative effects on healthy cells. Active immunotherapy can be employed for cancer immunotherapy by directly using the ingredients of the immune system and activating immune responses. On the other hand, inactive immunotherapy is utilized by indirect induction and using immune cell-based products consisting of monoclonal antibodies. It has strongly been proved that combination therapy with immunotherapies and other therapeutic means, such as anti-angiogenic agents, could be a rational plan to treat cancer. Herein, we have focused on recent findings concerning the therapeutic merits of cancer therapy using immune checkpoint inhibitors (ICIs), adoptive cell transfer (ACT) and cancer vaccine alone or in combination with other approaches. Also, we offer a glimpse into the current challenges in this context.

Manipulation of the crosstalk between tumor angiogenesis and immunosuppression in the tumor microenvironment: Insight into the combination therapy of anti-angiogenesis and immune checkpoint blockade

Immunotherapy has been recognized as an effective and important therapeutic modality for multiple types of cancer. Nevertheless, it has been increasing recognized that clinical benefits of immunotherapy are less than expected as evidenced by the fact that only a small population of cancer patients respond favorably to immunotherapy. The structurally and functionally abnormal tumor vasculature is a hallmark of most solid tumors and contributes to an immunosuppressive microenvironment, which poses a major challenge to immunotherapy. In turn, multiple immune cell subsets have profound consequences on promoting neovascularization. Vascular normalization, a promising anti-angiogenic strategy, can enhance vascular perfusion and promote the infiltration of immune effector cells into tumors via correcting aberrant tumor blood vessels, resulting in the potentiation of immunotherapy. More interestingly, immunotherapies are prone to boost the efficacy of various anti-angiogenic therapies and/or promote the morphological and functional alterations in tumor vasculature. Therefore, immune reprograming and vascular normalization appear to be reciprocally regulated. In this review, we mainly summarize how tumor vasculature propels an immunosuppressive phenotype and how innate and adaptive immune cells modulate angiogenesis during tumor progression. We further highlight recent advances of anti-angiogenic immunotherapies in preclinical and clinical settings to solidify the concept that targeting both tumor blood vessels and immune suppressive cells provides an efficacious approach for the treatment of cancer.

Cascade two-stage tumor re-oxygenation and immune re-sensitization mediated by self-assembled albumin-sorafenib nanoparticles for enhanced photodynamic immunotherapy

As a promising modality for cancer therapy, photodynamic therapy (PDT) still acquired limited success in clinical nowadays due to the extremely serious hypoxia and immunosuppression tumor microenvironment. To ameliorate such a situation, we rationally designed and prepared cascade two-stage re-oxygenation and immune re-sensitization BSA-MHI148@SRF nanoparticles via hydrophilic and hydrophobic self-assembly strategy by using near-infrared photodynamic dye MHI148 chemically modified bovine serum albumin (BSA-MHI148) and multi-kinase inhibitor Sorafenib (SRF) as a novel tumor oxygen and immune microenvironment regulation drug. Benefiting from the accumulation of SRF in tumors, BSA-MHI148@SRF nanoparticles dramatically enhanced the PDT efficacy by promoting cascade two-stage tumor re-oxygenation mechanisms: (i) SRF decreased tumor oxygen consumption via inhibiting mitochondria respiratory. (ii) SRF increased the oxygen supply via inducing tumor vessel normalization. Meanwhile, the immunosuppression micro-environment was also obviously reversed by two-stage immune re-sensitization as follows: (i) Enhanced immunogenic cell death (ICD) production amplified by BSA-MHI148@SRF induced reactive oxygen species (ROS) generation enhanced T cell infiltration and improve its tumor cell killing ability. (ii) BSA-MHI148@SRF amplified tumor vessel normalization by VEGF inhibition also obviously reversed the tumor immune-suppression microenvironment. Finally, the growth of solid tumors was significantly depressed by such well-designed BSA-MHI148@SRF nanoparticles, which could be potential for clinical cancer therapy.

Pivotal role of PD-1/PD-L1 immune checkpoints in immune escape and cancer progression: Their interplay with platelets and FOXP3+Tregs related molecules, clinical implications and combinational potential with phytochemicals

Immune checkpoint proteins including programmed cell death protein 1 (PD-1), its ligand PD-L1 and cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) are involved in proliferation, angiogenesis, metastasis, chemoresistance via immune escape and immune tolerance by disturbing cytotoxic T cell activation. Though many clinical trials have been completed in several cancers by using immune checkpoint inhibitors alone or in combination with other agents to date, recently multi-target therapy is considered more attractive than monotherapy, since immune checkpoint proteins work with other components such as surrounding blood vessels, dendritic cells, fibroblasts, macrophages, platelets and extracellular matrix within tumor microenvironment. Thus, in the current review, we look back on research history of immune checkpoint proteins and discuss their associations with platelets or tumor cell induced platelet aggregation (TCIPA) and FOXP3+ regulatory T cells (Tregs) related molecules involved in immune evasion and tumor progression, clinical implications of completed trial results and signaling networks by phytochemicals for combination therapy with immune checkpoint inhibitors and suggest future research perspectives.

Unraveling tumor microenvironment of small-cell lung cancer: implications for immunotherapy

Small-cell lung cancer (SCLC) is an aggressive lung cancer subtype and its first-line treatment has remained unchanged for decades. In recent years, immunotherapy has emerged as a therapeutic strategy for tumor treatment, whereas, patients with SCLC exhibit poor overall responses to immunotherapy alone, which highlights the necessity for combinatorial approaches. The tumor microenvironment (TME), an integral component in cancer, is widely implicated in tumorigenesis and tumor metastasis. The interactions of various cells within TME shape the adverse conditions of the tumor microenvironment (characterized by hypoxia, nutrient restriction, and acidity) and are considered responsible for the modest therapeutic responses to immunotherapy. Several studies have suggested that adverse TME can regulate immune cell activation and function. However, the specific regulatory mechanisms and their implications on immunotherapy remain unclear. Thus, it is worth unraveling the characteristics of TME and its impact on antitumor immunity, in the hope of devising novel strategies to reinforce immunotherapeutic effects on SCLC. In this review, we firstly elaborate on the immune landscape of SCLC and the formation of three remarkable characteristics in TME, as well as the interaction among them. Next, we summarize the latest findings regarding the impacts of adverse TME on immune cells and its targeted therapy in SCLC. Finally, we discuss the ongoing trials in combination therapy and potential directions of SCLC therapy. Collectively, the findings combined here are expected to aid the design of trials for combining immunotherapy with therapy targeting the TME of SCLC.

Chidamide plus Tyrosine Kinase Inhibitor Remodel the Tumor Immune Microenvironment and Reduce Tumor Progression When Combined with Immune Checkpoint Inhibitor in Naïve and Anti-PD-1 Resistant CT26-Bearing Mice

Combined inhibition of vascular endothelial growth factor receptor (VEGFR) and the programmed cell death protein 1 (PD-1) pathways has shown efficacy in multiple cancers; however, the clinical outcomes show limited benefits and the unmet clinical needs still remain and require improvement in efficacy. Using murine colon carcinoma (CT26) allograft models, we examined the efficacy and elucidated novel tumor microenvironment (TME) remodeling mechanisms underlying the combination of chidamide (a benzamide-based class l histone deacetylase inhibitor; brand name in Taiwan, Kepida®) with VEGF receptor tyrosine kinase inhibitor (TKIs; cabozantinib/regorafenib, etc.) and immune checkpoint inhibitors (ICIs; anti-PD-1/anti-PD-L1/anti-CTLA-4 antibodies). The TME was assessed using flow cytometry and RNA-sequencing to determine the novel mechanisms and their correlation with therapeutic effects in mice with significant treatment response. Compared with ICI alone or cabozantinib/regorafenib + ICI, combination of chidamide + cabozantinib/regorafenib + ICI increased the tumor response and survival benefits. In particular, treatment of CT26-bearing mice with chidamide + regorafenib + anti-PD-1 antibody showed a better objective response rate (ORR) and overall survival (OS). Similar results were observed in anti-PD-1 treatment-resistant mice. After treatment with this optimal combination, in the TME, RNA-sequencing revealed that downregulated mRNAs were correlated with leukocyte migration, cell chemotaxis, and macrophage gene sets, and flow cytometry analysis showed that the cell numbers of myeloid-derived polymorphonuclear suppressor cells and tumor-associated macrophages were decreased. Accordingly, chidamide + regorafenib + anti-PD-1 antibody combination therapy could trigger a novel TME remodeling mechanism by attenuating immunosuppressive cells, and restoring T-cell activation to enhance ORR and OS. Our studies also showed that the addition of Chidamide to the regorafenib + anti-PD-1 Ab combination could induce a durable tumor-specific response by attenuating immune suppression in the TME. In addition, this result suggests that TME remodeling, mediated by epigenetic immunomodulator combined with TKI and ICI, would be more advantageous for achieving a high objective response rate, when compared to TKI plus ICI or ICI alone, and maintaining long-lasting antitumor activity.

EGFR Inhibition Strongly Modulates the Tumour Immune Microenvironment in EGFR-Driven Non-Small-Cell Lung Cancer

Simple Summary

Lung cancer that is driven by mutations in the epidermal growth factor receptor (EGFR) is currently treated with tyrosine kinase inhibitors (TKIs). Although patients initially respond well to TKI treatment, drug resistance against EGFR-targeted therapy emerges. Attempts to combine immunotherapy with EGFR-targeted treatment to prolong response rates or prevent the development of resistances have been limited due to insufficient knowledge about the effects of targeted therapy on the tumour microenvironment (TME) in EGFR-driven tumours and tumour-infiltrating immune cells. The aims of this study were to improve our understanding on the impact of EGFR inhibition on the immune response in EGFR-driven lung cancer and, furthermore, to gain insights into the impact of combining targeted therapy with immunotherapy on the TME.

Abstract

EGFR-driven non-small-cell lung cancer (NSCLC) patients are currently treated with TKIs targeting EGFR, such as erlotinib or osimertinib. Despite a promising initial response to TKI treatment, most patients gain resistance to oncogene-targeted therapy, and tumours progress. With the development of inhibitors against immune checkpoints, such as PD-1, that mediate an immunosuppressive microenvironment, immunotherapy approaches attempt to restore a proinflammatory immune response in tumours. However, this strategy has shown only limited benefits in EGFR-driven NSCLC. Approaches combining EGFR inhibition with immunotherapy to stimulate the immune response and overcome resistance to therapy have been limited due to insufficient understanding about the effect of EGFR-targeting treatment on the immune cells in the TME. Here, we investigate the impact of EGFR inhibition by erlotinib on the TME and its effect on the antitumour response of the immune cell infiltrate. For this purpose, we used a transgenic conditional mouse model to study the immunological profile in EGFR-driven NSCLC tumours. We found that EGFR inhibition mediated a higher infiltration of immune cells and increased local proliferation of T-cells in the tumours. Moreover, inhibiting EGFR signalling led to increased activation of immune cells in the TME. Most strikingly, combined simultaneous blockade of EGFR and anti-PD-1 (aPD-1) enhanced tumour treatment response in a transgenic mouse model of EGFR-driven NSCLC. Thus, our findings show that EGFR inhibition promotes an active and proinflammatory immune cell infiltrate in the TME while improving response to immune checkpoint inhibitors in EGFR-driven NSCLC.

DDR1 functions as an immune negative factor in colorectal cancer by regulating tumor-infiltrating T cell through IL-18

Immunotherapies represented by programmed cell death protein 1/programmed cell death ligand 1 (PD‐1/PD‐L1) immune checkpoint inhibitors have made great progress in the field of anticancer treatment, but most colorectal cancer patients do not benefit from immunotherapy. Discoidin domain receptor 1 (DDR1), a tyrosine kinase receptor, is activated by collagen binding and overexpressed in various malignancies. However, the role of DDR1 in colorectal cancer and immunoregulation remains unclear. In this study, we found DDR1 is highly expressed in colorectal cancer tissues and negatively associated with patient survival. We demonstrated that DDR1 promotes colorectal tumor growth only in vivo. Mechanistically, DDR1 is a negative immunomodulator in colorectal cancer and is involved in low infiltration of CD4⁺ and CD8⁺ T cells by inhibiting IL‐18 synthesis. We also reported that DDR1 enhances the expression of PD‐L1 through activating the c‐Jun amino terminal kinase (JNK) signaling pathway. In conclusion, our findings elucidate the immunosuppressive role of DDR1 in colorectal cancer, which may represent a novel target to enhance the efficacy of immunotherapy in colorectal cancer.

Non-coding RNAs in lung cancer: emerging regulators of angiogenesis

Lung cancer is the second cancer and the leading cause of tumor-related mortality worldwide. Angiogenesis is a crucial hallmark of cancer development and a promising target in lung cancer. However, the anti-angiogenic drugs currently used in the clinic do not achieve long-term efficacy and are accompanied by severe adverse reactions. Therefore, the development of novel anti-angiogenic therapeutic approaches for lung cancer is urgently needed. Non-coding RNAs (ncRNAs) participate in multiple biological processes in cancers, including tumor angiogenesis. Many studies have demonstrated that ncRNAs play crucial roles in tumor angiogenesis. This review discusses the regulatory functions of different ncRNAs in lung cancer angiogenesis, focusing on the downstream targets and signaling pathways regulated by these ncRNAs. Additionally, given the recent trend towards utilizing ncRNAs as cancer therapeutics, we also discuss the tremendous potential applications of ncRNAs as biomarkers or novel anti-angiogenic tools in lung cancer.

Therapeutic targeting of VEGF and/or TGF-β to enhance anti-PD-(L)1 therapy: The evidence from clinical trials

Normalizing the tumor microenvironment (TME) is a potential strategy to improve the effectiveness of immunotherapy. Vascular endothelial growth factor (VEGF) and transforming growth factor (TGF)-β pathways play an important role in the development and function of the TME, contributing to the immunosuppressive status of TME. To inhibit VEGF and/or TGF-β pathways can restore TME from immunosuppressive to immune-supportive status and enhance sensitivity to immunotherapy such as programmed death protein-1 (PD-1)/programmed cell death-ligand 1 (PD-L1) inhibitors. In this review, we described the existing preclinical and clinical evidence supporting the use of anti-VEGF and/or anti-TGF-β therapies to enhance cancer immunotherapy. Encouragingly, adopting anti-VEGF and/or anti-TGF-β therapies as a combination treatment with anti-PD-(L)1 therapy have been demonstrated as effective and tolerable in several solid tumors in clinical trials. Although several questions need to be solved, the clinical value of this combination strategy is worthy to be studied further.

Toripalimab and anlotinib as a maintenance treatment for extensive-stage small-cell lung cancer: a case report

Small-cell lung cancer (SCLC) is characterized by rapid proliferation, high growth fraction and early locoregional and distant metastases. SCLC has been found to be significantly sensitive to platinum–etoposide chemotherapy, but most patients relapse within 6 months of completing initial treatment and median overall survival is about 10 months. Despite the current immunotherapy-treatment approach, median survival time and progression-free survival remain short. This case shows the potential efficacy of maintenance therapy with toripalimab and anlotinib after first-line platinum–etoposide chemotherapy in a patient with extensive-stage SCLC. The combination treatment prolonged the progression-free survival to approximately 13 months and overall survival to 25 months; this is well above the existing standard, and this patient did not experience any major adverse effects during the course of therapy.

Treatment with a VEGFR-2 antibody results in intra-tumor immune modulation and enhances anti-tumor efficacy of PD-L1 blockade in syngeneic murine tumor models

Prolonged activation of vascular endothelial growth factor receptor-2 (VEGFR-2) due to mis-regulation of the VEGF pathway induces aberrant blood vessel expansion, which supports growth and survival of solid tumors. Therapeutic interventions that inhibit the VEGFR-2 pathway have therefore become a mainstay of cancer treatment. Non-clinical studies have recently revealed that blockade of angiogenesis can modulate the tumor microenvironment and enhance the efficacy of concurrent immune therapies. Ramucirumab is an FDA-approved anti-angiogenic antibody that inhibits VEGFR-2 and is currently being evaluated in clinical studies in combination with anti-programmed cell death (PD-1) axis checkpoint inhibitors (pembrolizumab, durvalumab, or sintilimab) across several cancer types. The purpose of this study is to establish a mechanistic basis for the enhanced activity observed in the combined blockade of VEGFR-2 and PD-1-axis pathways. Pre-clinical studies were conducted in murine tumor models known to be responsive to anti-PD-1 axis therapy, using monoclonal antibodies that block mouse VEGFR-2 and programmed death-ligand 1 (PD-L1). Combination therapy resulted in enhanced anti-tumor activity compared to anti-PD-L1 monotherapy. VEGFR-2 blockade at early timepoints post-anti-PD-L1 therapy resulted in a dose-dependent and transient enhanced infiltration of T cells, and establishment of immunological memory. VEGFR-2 blockade at later timepoints resulted in enhancement of anti-PD-L1-driven immune cell infiltration. VEGFR-2 and PD-L1 monotherapies induced both unique and overlapping patterns of immune gene expression, and combination therapy resulted in an enhanced immune activation signature. Collectively, these results provide new and actionable insights into the mechanisms by which concurrent VEGFR-2 and PD-L1 antibody therapy leads to enhanced anti-tumor efficacy.

The Multi-Kinase Inhibitor Lucitanib Enhances the Antitumor Activity of Coinhibitory and Costimulatory Immune Pathway Modulators in Syngeneic Models

Lucitanib is a multi-tyrosine kinase inhibitor whose targets are associated with angiogenesis and other key cancer and immune pathways. Its antiangiogenic properties are understood, but lucitanib's immunomodulatory activity is heretofore unknown. Lucitanib exhibited such activity in vivo, increasing CD3+, CD8+, and CD4+ T cells and decreasing dendritic cells and monocyte-derived suppressor cells in mouse spleens. Depletion of CD8+ T cells from syngeneic MC38 colon tumor-bearing mice reduced the antitumor efficacy of lucitanib and revealed a CD8+ T-cell-dependent component of lucitanib's activity. The combination of lucitanib and costimulatory immune pathway agonists targeting 4-1BB, glucocorticoid-induced TNFR (GITR), inducible T-cell co-stimulator (ICOS), or OX40 exhibited enhanced antitumor activity compared with each single agent in immunocompetent tumor models. Lucitanib combined with blockade of cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) or programmed cell death protein-1 (PD-1) coinhibitory immune pathways also showed enhanced antitumor activity over the single agents in multiple models. In CT26 tumors, lucitanib, alone or combined with anti-PD-1, reduced CD31+ vessels and depleted F4/80+ macrophages. Combination treatment also increased the number of intratumoral T cells. Gene expression in pathways associated with immune activity was upregulated by lucitanib in MC38 tumors and further potentiated by combination with anti-PD-1. Accordingly, lucitanib, alone or combined with anti-PD-1, increased intratumoral CD8+ T-cell abundance. Lucitanib's antitumor and pharmacodynamic activity, alone or combined with anti-PD-1, was not recapitulated by specific vascular endothelial growth factor receptor-2 (VEGFR2) inhibition. These data indicate that lucitanib can modulate vascular and immune components of the tumor microenvironment and cooperate with immunotherapy to enhance antitumor efficacy. They support the clinical development of lucitanib combined with immune pathway modulators to treat cancer.

Combined application of bevacizumab and PD-1 blockade displays durable treatment effects by increasing the infiltration and cytotoxic function of CD8+ T cells in lung cancer

Aim: VEGF/VEGFR inhibitors may help immune checkpoint inhibitors expand the population that will benefit from treatment. The authors investigated the efficacy of combined bevacizumab and PD-1 antibody. Materials & methods: C57BL/6J mice were injected subcutaneously with 1 × 10⁶ Lewis lung carcinoma cells. The mice were intraperitoneally injected with 0.25 mg anti-PD-1 inhibitors and/or 15 mg/kg bevacizumab. Tumor tissues were harvested. The authors reported that a non-small cell lung cancer patient received 200 mg PD-1 antibody combined with 7.5 mg/kg bevacizumab as fourth-line treatment. Results: Bevacizumab combined with PD-1 antibody induced a strong and durable antitumor effect. Bevacizumab combined with PD-1 antibody improved abnormal tumor vessels and enhanced the cytotoxic function and infiltration of T lymphocytes. The patient's survival time was significantly prolonged. Conclusion: Bevacizumab combined with anti-PD-1 antibody induces a durable antitumor effect by increasing the infiltration and cytotoxic function of CD8⁺ T cells in lung cancer.

Efficacy and Safety of PD-1/PD-L1 Inhibitor Chemotherapy Combined with Lung Cancer Fang No. 1 in Relapsed and Refractory SCLC: A Retrospective Observational Study

Background

Relapsed and refractory small cell lung cancer (SCLC) accounts for about 15% of all lung cancers. The prognosis of patients is poor. The 5-year survival rate is almost 0. The average survival time of patients who refuse to receive treatment is only 2-4 months. For patients with extensive-stage SCLC, the current first-line treatment regimens are mainly platinum-containing double-drug chemotherapy. Poside combined with cisplatin/carboplatin and irinotecan combined with cisplatin/carboplatin are commonly used clinical regimens for the treatment of patients with extensive-stage SCLC. Although SCLC is very sensitive to radiotherapy and chemotherapy, most patients will develop recurrence and metastasis after initial treatment. Therefore, it is necessary to study clinically effective therapeutic drugs for relapsed and refractory SCLC.

Objective

To investigate the relationship between programmed death receptor-1 (programmed death receptor-1 (PD-1)) and programmed death receptor-ligand 1 (programmed death-ligand 1 (PD-L1)) inhibitors and Lung Cancer No. 1 efficacy and safety of Lung Cancer Fang No. 1 in the treatment of relapsed and refractory SCLC.

Methods

80 patients with refractory SCLC were selected and randomly divided into control group and treatment group with 40 cases in each group. Among them, the control group received PD-1/PD-L1 inhibitor chemotherapy, and the treatment group received PD-1/PD-L1 inhibitor chemotherapy combined with Lung Cancer Fang No. 1 treatment. The differences in immune and tumor marker levels, clinical efficacy, and prognostic complications between the two groups before and after treatment were observed and compared.

Results

Before treatment, there was no significant difference in clinical improvement between the two groups. After treatment, the clinical symptom scores and body weight changes in the treatment group were significantly improved. The clinical symptom scores in the treatment group were lower than those in the control group, but the body weight changes were higher than those in the control group. The difference was statistically significant (P < 0.05). Before treatment, there was no significant difference in the levels of tumor markers between the two groups. After treatment, the levels of CYFRA21-1, CA125, and VGEF in the treatment group were significantly lower than those in the control group, and the difference was statistically significant (P < 0.05). There was no significant difference in the immune level between the two groups before treatment (P > 0.05), while the differences in CD4+, CD3+, and CD4+/CD8+ after treatment were significant, and the treatment group was higher than the control group, with statistical significance (P < 0.05). After treatment, the clinical efficacy of the two groups was significantly improved. The DCR90.00% of the treatment group was significantly higher than that of the control group, 67.50%, and the difference was statistically significant (P < 0.05). The analysis of complications after treatment showed that fatigue, anorexia, hypertension, hand-foot syndrome, diarrhea, leukopenia, thrombocytopenia, and urinary protein in the treatment group were significantly lower than those in the control group, and the difference was statistically significant (P < 0.05).

Conclusion

PD-1/PD-L1 inhibitor chemotherapy combined with Lung Cancer Fang No. 1 has a good and safe effect on SCLC patients. It has a good curative effect in improving the clinical symptoms of patients. It can stabilize the tumor, inhibit the development of lung cancer, improve the body's cellular immune function, adjust the level and expression of tumor markers, improve the body's material metabolism, and restore the balance of yin and yang in the body.